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• Validating a linked item&rsquo;s data template in Sitecore

  - by Kyle Burns

  I’ve been doing quite a bit of work in Sitecore recently and last week I encountered a situation that it appears many others have hit.  I was working with a field that had been configured originally as a grouped droplink, but now needed to be updated to support additional levels of hierarchy in the folder structure.  If you’ve done any work in Sitecore that statement makes sense, but if not it may seem a bit cryptic.  Sitecore offers a number of different field types and a subset of these field types focus on providing links either to other items on the content tree or to content that is not stored in Sitecore.  In the case of the grouped droplink, the field is configured with a “root” folder and each direct descendant of this folder is considered to be a header for a grouping of other items and displayed in a dropdown.  A picture is worth a thousand words, so consider the following piece of a content tree: If I configure a grouped droplink field to use the “Current” folder as its datasource, the control that gets to my content author looks like this: This presents a nicely organized display and limits the user to selecting only the direct grandchildren of the folder root.  It also presents the limitation that struck as we were thinking through the content architecture and how it would hold up over time – the authors cannot further organize content under the root folder because of the structure required for the dropdown to work.  Over time, not allowing the hierarchy to go any deeper would prevent out authors from being able to organize their content in a way that it would be found when needed, so the grouped droplink data type was not going to fit the bill. I needed to look for an alternative data type that allowed for selection of a single item and limited my choices to descendants of a specific node on the content tree.  After looking at the options available for links in Sitecore and considering them against each other, one option stood out as nearly perfect – the droptree.  This field type stores its data identically to the droplink and allows for the selection of zero or one items under a specific node in the content tree.  By changing my data template to use droptree instead of grouped droplink, the author is now presented with the following when selecting a linked item: Sounds great, but a did say almost perfect – there’s still one flaw.  The code intended to display the linked item is expecting the selection to use a specific data template (or more precisely it makes certain assumptions about the fields that will be present), but the droptree does nothing to prevent the author from selecting a folder (since folders are items too) instead of one of the items contained within a folder.  I looked to see if anyone had already solved this problem.  I found many people discussing the problem, but the closest that I found to a solution was the statement “the best thing would probably be to create a custom validator” with no further discussion in regards to what this validator might look like.  I needed to create my own validator to ensure that the user had not selected a folder.  Since so many people had the same issue, I decided to make the validator as reusable as possible and share it here. The validator that I created inherits from StandardValidator.  In order to make the validator more intuitive to developers that are familiar with the TreeList controls in Sitecore, I chose to implement the following parameters: ExcludeTemplatesForSelection – serves as a “deny list”.  If the data template of the selected item is in this list it will not validate IncludeTemplatesForSelection – this can either be empty to indicate that any template not contained in the exclusion list is acceptable or it can contain the list of acceptable templates Now that I’ve explained the parameters and the purpose of the validator, I’ll let the code do the rest of the talking: 1: /// <summary> 2: /// Validates that a link field value meets template requirements 3: /// specified using the following parameters: 4: /// - ExcludeTemplatesForSelection: If present, the item being 5: /// based on an excluded template will cause validation to fail. 6: /// - IncludeTemplatesForSelection: If present, the item not being 7: /// based on an included template will cause validation to fail 8: /// 9: /// ExcludeTemplatesForSelection trumps IncludeTemplatesForSelection 10: /// if the same value appears in both lists. Lists are comma seperated 11: /// </summary> 12: [Serializable] 13: public class LinkItemTemplateValidator : StandardValidator 14: { 15: public LinkItemTemplateValidator() 16: { 17: } 18:   19: /// <summary> 20: /// Serialization constructor is required by the runtime 21: /// </summary> 22: /// <param name="info"></param> 23: /// <param name="context"></param> 24: public LinkItemTemplateValidator(SerializationInfo info, StreamingContext context) : base(info, context) { } 25:   26: /// <summary> 27: /// Returns whether the linked item meets the template 28: /// constraints specified in the parameters 29: /// </summary> 30: /// <returns> 31: /// The result of the evaluation. 32: /// </returns> 33: protected override ValidatorResult Evaluate() 34: { 35: if (string.IsNullOrWhiteSpace(ControlValidationValue)) 36: { 37: return ValidatorResult.Valid; // let "required" validation handle 38: } 39:   40: var excludeString = Parameters["ExcludeTemplatesForSelection"]; 41: var includeString = Parameters["IncludeTemplatesForSelection"]; 42: if (string.IsNullOrWhiteSpace(excludeString) && string.IsNullOrWhiteSpace(includeString)) 43: { 44: return ValidatorResult.Valid; // "allow anything" if no params 45: } 46:   47: Guid linkedItemGuid; 48: if (!Guid.TryParse(ControlValidationValue, out linkedItemGuid)) 49: { 50: return ValidatorResult.Valid; // probably put validator on wrong field 51: } 52:   53: var item = GetItem(); 54: var linkedItem = item.Database.GetItem(new ID(linkedItemGuid)); 55:   56: if (linkedItem == null) 57: { 58: return ValidatorResult.Valid; // this validator isn't for broken links 59: } 60:   61: var exclusionList = (excludeString ?? string.Empty).Split(','); 62: var inclusionList = (includeString ?? string.Empty).Split(','); 63:   64: if ((inclusionList.Length == 0 || inclusionList.Contains(linkedItem.TemplateName)) 65: && !exclusionList.Contains(linkedItem.TemplateName)) 66: { 67: return ValidatorResult.Valid; 68: } 69:   70: Text = GetText("The field \"{0}\" specifies an item which is based on template \"{1}\". This template is not valid for selection", GetFieldDisplayName(), linkedItem.TemplateName); 71:   72: return GetFailedResult(ValidatorResult.FatalError); 73: } 74:   75: protected override ValidatorResult GetMaxValidatorResult() 76: { 77: return ValidatorResult.FatalError; 78: } 79:   80: public override string Name 81: { 82: get { return @"LinkItemTemplateValidator"; } 83: } 84: }   In this blog entry, I have shared some code that I found useful in solving a problem that seemed fairly common.  Hopefully the next person that is looking for this answer finds it useful as well.

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• Tricks and Optimizations for you Sitecore website

  - by amaniar

  When working with Sitecore there are some optimizations/configurations I usually repeat in order to make my app production ready. Following is a small list I have compiled from experience, Sitecore documentation, communicating with Sitecore Engineers etc. This is not supposed to be technically complete and might not be fit for all environments.   Simple configurations that can make a difference: 1) Configure Sitecore Caches. This is the most straight forward and sure way of increasing the performance of your website. Data and item cache sizes (/databases/database/ [id=web] ) should be configured as needed. You may start with a smaller number and tune them as needed. <cacheSizes hint="setting"> <data>300MB</data> <items>300MB</items> <paths>5MB</paths> <standardValues>5MB</standardValues> </cacheSizes> Tune the html, registry etc cache sizes for your website.   <cacheSizes> <sites> <website> <html>300MB</html> <registry>1MB</registry> <viewState>10MB</viewState> <xsl>5MB</xsl> </website> </sites> </cacheSizes> Tune the prefetch cache settings under the App_Config/Prefetch/ folder. Sample /App_Config/Prefetch/Web.Config: <configuration> <cacheSize>300MB</cacheSize> <!--preload items that use this template--> <template desc="mytemplate">{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}</template> <!--preload this item--> <item desc="myitem">{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX }</item> <!--preload children of this item--> <children desc="childitems">{XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX}</children> </configuration> Break your page into sublayouts so you may cache most of them. Read the caching configuration reference: http://sdn.sitecore.net/upload/sitecore6/sc62keywords/cache_configuration_reference_a4.pdf   2) Disable Analytics for the Shell Site <site name="shell" virtualFolder="/sitecore/shell" physicalFolder="/sitecore/shell" rootPath="/sitecore/content" startItem="/home" language="en" database="core" domain="sitecore" loginPage="/sitecore/login" content="master" contentStartItem="/Home" enableWorkflow="true" enableAnalytics="false" xmlControlPage="/sitecore/shell/default.aspx" browserTitle="Sitecore" htmlCacheSize="2MB" registryCacheSize="3MB" viewStateCacheSize="200KB" xslCacheSize="5MB" />   3) Increase the Check Interval for the MemoryMonitorHook so it doesn’t run every 5 seconds (default). <hook type="Sitecore.Diagnostics.MemoryMonitorHook, Sitecore.Kernel"> <param desc="Threshold">800MB</param> <param desc="Check interval">00:05:00</param> <param desc="Minimum time between log entries">00:01:00</param> <ClearCaches>false</ClearCaches> <GarbageCollect>false</GarbageCollect> <AdjustLoadFactor>false</AdjustLoadFactor> </hook>   4) Set Analytics.PeformLookup (Sitecore.Analytics.config) to false if your environment doesn’t have access to the internet or you don’t intend to use reverse DNS lookup. <setting name="Analytics.PerformLookup" value="false" />   5) Set the value of the “Media.MediaLinkPrefix” setting to “-/media”: <setting name="Media.MediaLinkPrefix" value="-/media" /> Add the following line to the customHandlers section: <customHandlers> <handler trigger="-/media/" handler="sitecore_media.ashx" /> <handler trigger="~/media/" handler="sitecore_media.ashx" /> <handler trigger="~/api/" handler="sitecore_api.ashx" /> <handler trigger="~/xaml/" handler="sitecore_xaml.ashx" /> <handler trigger="~/icon/" handler="sitecore_icon.ashx" /> <handler trigger="~/feed/" handler="sitecore_feed.ashx" /> </customHandlers> Link: http://squad.jpkeisala.com/2011/10/sitecore-media-library-performance-optimization-checklist/   6) Performance counters should be disabled in production if not being monitored <setting name="Counters.Enabled" value="false" />   7) Disable Item/Memory/Timing threshold warnings. Due to the nature of this component, it brings no value in production. <!--<processor type="Sitecore.Pipelines.HttpRequest.StartMeasurements, Sitecore.Kernel" />--> <!--<processor type="Sitecore.Pipelines.HttpRequest.StopMeasurements, Sitecore.Kernel"> <TimingThreshold desc="Milliseconds">1000</TimingThreshold> <ItemThreshold desc="Item count">1000</ItemThreshold> <MemoryThreshold desc="KB">10000</MemoryThreshold> </processor>—>   8) The ContentEditor.RenderCollapsedSections setting is a hidden setting in the web.config file, which by default is true. Setting it to false will improve client performance for authoring environments. <setting name="ContentEditor.RenderCollapsedSections" value="false" />   9) Add a machineKey section to your Web.Config file when using a web farm. Link: http://msdn.microsoft.com/en-us/library/ff649308.aspx   10) If you get errors in the log files similar to: WARN Could not create an instance of the counter 'XXX.XXX' (category: 'Sitecore.System') Exception: System.UnauthorizedAccessException Message: Access to the registry key 'Global' is denied. Make sure the ApplicationPool user is a member of the system “Performance Monitor Users” group on the server.   11) Disable WebDAV configurations on the CD Server if not being used. More: http://sitecoreblog.alexshyba.com/2011/04/disable-webdav-in-sitecore.html   12) Change Log4Net settings to only log Errors on content delivery environments to avoid unnecessary logging. <root> <priority value="ERROR" /> <appender-ref ref="LogFileAppender" /> </root>   13) Disable Analytics for any content item that doesn’t add value. For example a page that redirects to another page.   14) When using Web User Controls avoid registering them on the page the asp.net way: <%@ Register Src="~/layouts/UserControls/MyControl.ascx" TagName="MyControl" TagPrefix="uc2" %> Use Sublayout web control instead – This way Sitecore caching could be leveraged <sc:Sublayout ID="ID" Path="/layouts/UserControls/MyControl.ascx" Cacheable="true" runat="server" />   15) Avoid querying for all children recursively when all items are direct children. Sitecore.Context.Database.SelectItems("/sitecore/content/Home//*"); //Use: Sitecore.Context.Database.GetItem("/sitecore/content/Home");   16) On IIS — you enable static & dynamic content compression on CM and CD More: http://technet.microsoft.com/en-us/library/cc754668%28WS.10%29.aspx   17) Enable HTTP Keep-alive and content expiration in IIS.   18) Use GUID’s when accessing items and fields instead of names or paths. Its faster and wont break your code when things get moved or renamed. Context.Database.GetItem("{324DFD16-BD4F-4853-8FF1-D663F6422DFF}") Context.Item.Fields["{89D38A8F-394E-45B0-826B-1A826CF4046D}"]; //is better than Context.Database.GetItem("/Home/MyItem") Context.Item.Fields["FieldName"]   Hope this helps.

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• Azure, don't give me multiple VMs, give me one elastic VM

  - by FransBouma

  Yesterday, Microsoft revealed new major features for Windows Azure (see ScottGu's post). It all looks shiny and great, but after reading most of the material describing the new features, I still find the overall idea behind all of it flawed: why should I care on how much VMs my web app runs? Isn't that a problem to solve for the Windows Azure engineers / software? And what if I need the file system, why can't I simply get a virtual filesystem ? To illustrate my point, let's use a real example: a product website with a customer system/database and next to it a support site with accompanying database. Both are written in .NET, using ASP.NET and use a SQL Server database each. The product website offers files to download by customers, very simple. You have a couple of options to host these websites: Buy a server, place it in a rack at an ISP and run the sites on that server Use 'shared hosting' with an ISP, which means your sites' appdomains are running on the same machine, as well as the files stored, and the databases are hosted in the same server as the other shared databases. Hire a VM, install your OS of choice at an ISP, and host the sites on that VM, basically the same as the first option, except you don't have a physical server At some cloud-vendor, either host the sites 'shared' or in a VM. See above. With all of those options, scalability is a problem, even the cloud-based ones, though not due to the same reasons: The physical server solution has the obvious problem that if you need more power, you need to buy a bigger server or more servers which requires you to add replication and other overhead Shared hosting solutions are almost always capped on memory usage / traffic and database size: if your sites get too big, you have to move out of the shared hosting environment and start over with one of the other solutions The VM solution, be it a VM at an ISP or 'in the cloud' at e.g. Windows Azure or Amazon, in theory allows scaling out by simply instantiating more VMs, however that too introduces the same overhead problems as with the physical servers: suddenly more than 1 instance runs your sites. If a cloud vendor offers its services in the form of VMs, you won't gain much over having a VM at some ISP: the main problems you have to work around are still there: when you spin up more than one VM, your application must be completely stateless at any moment, including the DB sub system, because what's in memory in instance 1 might not be in memory in instance 2. This might sounds trivial but it's not. A lot of the websites out there started rather small: they were perfectly runnable on a single machine with normal memory and CPU power. After all, you don't need a big machine to run a website with even thousands of users a day. Moving these sites to a multi-VM environment will cause a problem: all the in-memory state they use, all the multi-page transitions they use while keeping state across the transition, they can't do that anymore like they did that on a single machine: state is something of the past, you have to store every byte of state in either a DB or in a viewstate or in a cookie somewhere so with the next request, all state information is available through the request, as nothing is kept in-memory. Our example uses a bunch of files in a file system. Using multiple VMs will require that these files move to a cloud storage system which is mounted in each VM so we don't have to store the files on each VM. This might require different file paths, but this change should be minor. What's perhaps less minor is the maintenance procedure in place on the new type of cloud storage used: instead of ftp-ing into a VM, you might have to update the files using different ways / tools. All in all this makes moving an existing website which was written for an environment that's based around a VM (namely .NET with its CLR) overly cumbersome and problematic: it forces you to refactor your website system to be able to be used 'in the cloud', which is caused by the limited way how e.g. Windows Azure offers its cloud services: in blocks of VMs. Offer a scalable, flexible VM which extends with my needs Instead, cloud vendors should offer simply one VM to me. On that VM I run the websites, store my DB and my files. As it's a virtual machine, how this machine is actually ran on physical hardware (e.g. partitioned), I don't care, as that's the problem for the cloud vendor to solve. If I need more resources, e.g. I have more traffic to my server, way more visitors per day, the VM stretches, like I bought a bigger box. This frees me from the problem which comes with multiple VMs: I don't have any refactoring to do at all: I can simply build my website as if it runs on my local hardware server, upload it to the VM offered by the cloud vendor, install it on the VM and I'm done. "But that might require changes to windows!" Yes, but Microsoft is Windows. Windows Azure is their service, they can make whatever change to what they offer to make it look like it's windows. Yet, they're stuck, like Amazon, in thinking in VMs, which forces developers to 'think ahead' and gamble whether they would need to migrate to a cloud with multiple VMs in the future or not. Which comes down to: gamble whether they should invest time in code / architecture which they might never need. (YAGNI anyone?) So the VM we're talking about, is that a low-level VM which runs a guest OS, or is that VM a different kind of VM? The flexible VM: .NET's CLR ? My example websites are ASP.NET based, which means they run inside a .NET appdomain, on the .NET CLR, which is a VM. The only physical OS resource the sites need is the file system, however this too is accessed through .NET. In short: all the websites see is what .NET allows the websites to see, the world as the websites know it is what .NET shows them and lets them access. How the .NET appdomain is run physically, that's the concern of .NET, not mine. This begs the question why Windows Azure doesn't offer virtual appdomains? Or better: .NET environments which look like one machine but could be physically multiple machines. In such an environment, no change has to be made to the websites to migrate them from a local machine or own server to the cloud to get proper scaling: the .NET VM will simply scale with the need: more memory needed, more CPU power needed, it stretches. What it offers to the application running inside the appdomain is simply increasing, but not fragmented: all resources are available to the application: this means that the problem of how to scale is back to where it should be: with the cloud vendor. "Yeah, great, but what about the databases?" The .NET application communicates with the database server through a .NET ADO.NET provider. Where the database is located is not a problem of the appdomain: the ADO.NET provider has to solve that. I.o.w.: we can host the databases in an environment which offers itself as a single resource and is accessible through one connection string without replication overhead on the outside, and use that environment inside the .NET VM as if it was a single DB. But what about memory replication and other problems? This environment isn't simple, at least not for the cloud vendor. But it is simple for the customer who wants to run his sites in that cloud: no work needed. No refactoring needed of existing code. Upload it, run it. Perhaps I'm dreaming and what I described above isn't possible. Yet, I think if cloud vendors don't move into that direction, what they're offering isn't interesting: it doesn't solve a problem at all, it simply offers a way to instantiate more VMs with the guest OS of choice at the cost of me needing to refactor my website code so it can run in the straight jacket form factor dictated by the cloud vendor. Let's not kid ourselves here: most of us developers will never build a website which needs a truck load of VMs to run it: almost all websites created by developers can run on just a few VMs at most. Yet, the most expensive change is right at the start: moving from one to two VMs. As soon as you have refactored your website code to run across multiple VMs, adding another one is just as easy as clicking a mouse button. But that first step, that's the problem here and as it's right there at the beginning of scaling the website, it's particularly strange that cloud vendors refuse to solve that problem and leave it to the developers to solve that. Which makes migrating 'to the cloud' particularly expensive.

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• Gnome Do not Launching

  - by PyRulez

  When I try running gnome do, I get this. chris@Chris-Ubuntu-Laptop:~$ gnome-do pgrep: invalid user name: -u and it is not writable Trying sudo: chris@Chris-Ubuntu-Laptop:~$ sudo gnome-do [NetworkService] Could not initialize Network Manager dbus: Unable to open the session message bus. [Error 17:54:30.122] [SystemService] Could not initialize dbus: Unable to open the session message bus. (Do:2401): Wnck-CRITICAL **: wnck_set_client_type got called multiple times. (Do:2401): libdo-WARNING **: Binding '<Super>space' failed! [Error 17:54:30.649] [AbstractKeyBindingService] Key "" is already mapped. Tomboy.NotesItemSource "Tomboy Notes" encountered an error in UpdateItems: System.TypeInitializationException: An exception was thrown by the type initializer for Tomboy.TomboyDBus ---> System.Exception: Unable to open the session message bus. ---> System.ArgumentNullException: Argument cannot be null. Parameter name: address at NDesk.DBus.Bus.Open (System.String address) [0x00000] in <filename unknown>:0 at NDesk.DBus.Bus.get_Session () [0x00000] in <filename unknown>:0 --- End of inner exception stack trace --- at NDesk.DBus.Bus.get_Session () [0x00000] in <filename unknown>:0 at Tomboy.TomboyDBus..cctor () [0x00000] in <filename unknown>:0 --- End of inner exception stack trace --- at Tomboy.NotesItemSource.UpdateItems () [0x00000] in <filename unknown>:0 at Do.Universe.Safe.SafeItemSource.UpdateItems () [0x00000] in <filename unknown>:0 . Firefox.PlacesItemSource "Firefox Places" encountered an error in UpdateItems: System.InvalidCastException: Cannot cast from source type to destination type. at Mono.Data.Sqlite.SqliteDataReader.VerifyType (Int32 i, DbType typ) [0x00000] in <filename unknown>:0 at Mono.Data.Sqlite.SqliteDataReader.GetString (Int32 i) [0x00000] in <filename unknown>:0 at Firefox.PlacesItemSource+<LoadPlaceItems>c__Iterator3.MoveNext () [0x00000] in <filename unknown>:0 at System.Collections.Generic.List`1[Firefox.PlaceItem].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0 at System.Collections.Generic.List`1[Firefox.PlaceItem]..ctor (IEnumerable`1 collection) [0x00000] in <filename unknown>:0 at System.Linq.Enumerable.ToArray[PlaceItem] (IEnumerable`1 source) [0x00000] in <filename unknown>:0 at Firefox.PlacesItemSource.UpdateItems () [0x00000] in <filename unknown>:0 at Do.Universe.Safe.SafeItemSource.UpdateItems () [0x00000] in <filename unknown>:0 . Do.Universe.Linux.GNOMESpecialLocationsItemSource "GNOME Special Locations" encountered an error in UpdateItems: System.IO.FileNotFoundException: Could not find file "/root/.gtk-bookmarks". File name: '/root/.gtk-bookmarks' at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options) [0x00000] in <filename unknown>:0 at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share) [0x00000] in <filename unknown>:0 at (wrapper remoting-invoke-with-check) System.IO.FileStream:.ctor (string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare) at System.IO.File.OpenRead (System.String path) [0x00000] in <filename unknown>:0 at System.IO.StreamReader..ctor (System.String path, System.Text.Encoding encoding, Boolean detectEncodingFromByteOrderMarks, Int32 bufferSize) [0x00000] in <filename unknown>:0 at System.IO.StreamReader..ctor (System.String path) [0x00000] in <filename unknown>:0 at (wrapper remoting-invoke-with-check) System.IO.StreamReader:.ctor (string) at Do.Universe.Linux.GNOMESpecialLocationsItemSource+<ReadBookmarkItems>c__Iterator3.MoveNext () [0x00000] in <filename unknown>:0 at Do.Universe.Linux.GNOMESpecialLocationsItemSource.UpdateItems () [0x00000] in <filename unknown>:0 at Do.Universe.Safe.SafeItemSource.UpdateItems () [0x00000] in <filename unknown>:0 . ^[^\Full thread dump: "<unnamed thread>" tid=0x0xb7570700 this=0x0x56f18 thread handle 0x403 state : not waiting owns () at (wrapper managed-to-native) Mono.Unix.Native.Syscall.read (int,intptr,ulong) <0xffffffff> at Mono.Unix.Native.Syscall.read (int,void*,ulong) <0x00023> at Mono.Unix.UnixStream.Read (byte[],int,int) <0x0008b> at NDesk.DBus.Connection.ReadMessage () <0x0003c> at NDesk.DBus.Connection.Iterate () <0x0001b> at NDesk.DBus.BusG/<Init>c__AnonStorey0.<>m__0 (intptr,NDesk.GLib.IOCondition,intptr) <0x00033> at (wrapper native-to-managed) NDesk.DBus.BusG/<Init>c__AnonStorey0.<>m__0 (intptr,NDesk.GLib.IOCondition,intptr) <0xffffffff> at (wrapper managed-to-native) Gtk.Clipboard.gtk_clipboard_wait_is_text_available (intptr) <0xffffffff> at Gtk.Clipboard.WaitIsTextAvailable () <0x00017> at Do.Universe.SelectedTextItem.UpdateSelection (object,System.EventArgs) <0x00027> at Do.Platform.AbstractApplicationService.OnSummoned () <0x00025> at Do.Platform.ApplicationService.<ApplicationService>m__31 (object,System.EventArgs) <0x00013> at Do.Core.Controller.OnSummoned () <0x00025> at Do.Core.Controller.Summon () <0x00027> at Do.Do.Main (string[]) <0x001eb> at (wrapper runtime-invoke) <Module>.runtime_invoke_void_object (object,intptr,intptr,intptr) <0xffffffff> "<unnamed thread>" tid=0x0xb2c81b40 this=0x0x194150 thread handle 0x412 state : interrupted state owns () at (wrapper managed-to-native) System.IO.InotifyWatcher.ReadFromFD (intptr,byte[],intptr) <0xffffffff> at System.IO.InotifyWatcher.Monitor () <0x0005f> at System.Threading.Thread.StartInternal () <0x00057> at (wrapper runtime-invoke) object.runtime_invoke_void__this__ (object,intptr,intptr,intptr) <0xffffffff> "Universe Update Dispatcher" tid=0x0xb29ffb40 this=0x0x569d8 thread handle 0x41b state : interrupted state owns () at (wrapper managed-to-native) System.Threading.WaitHandle.WaitOne_internal (System.Threading.WaitHandle,intptr,int,bool) <0xffffffff> at System.Threading.WaitHandle.WaitOne (System.TimeSpan,bool) <0x00133> at System.Threading.WaitHandle.WaitOne (System.TimeSpan) <0x00022> at Do.Core.UniverseManager.UniverseUpdateLoop () <0x0007a> at System.Threading.Thread.StartInternal () <0x00057> at (wrapper runtime-invoke) object.runtime_invoke_void__this__ (object,intptr,intptr,intptr) <0xffffffff> Tomboy.NotesItemSource "Tomboy Notes" encountered an error in UpdateItems: System.TypeInitializationException: An exception was thrown by the type initializer for Tomboy.TomboyDBus ---> System.Exception: Unable to open the session message bus. ---> System.ArgumentNullException: Argument cannot be null. Parameter name: address at NDesk.DBus.Bus.Open (System.String address) [0x00000] in <filename unknown>:0 at NDesk.DBus.Bus.get_Session () [0x00000] in <filename unknown>:0 --- End of inner exception stack trace --- at NDesk.DBus.Bus.get_Session () [0x00000] in <filename unknown>:0 at Tomboy.TomboyDBus..cctor () [0x00000] in <filename unknown>:0 --- End of inner exception stack trace --- at Tomboy.NotesItemSource.UpdateItems () [0x00000] in <filename unknown>:0 at Do.Universe.Safe.SafeItemSource.UpdateItems () [0x00000] in <filename unknown>:0 . Firefox.PlacesItemSource "Firefox Places" encountered an error in UpdateItems: System.InvalidCastException: Cannot cast from source type to destination type. at Mono.Data.Sqlite.SqliteDataReader.VerifyType (Int32 i, DbType typ) [0x00000] in <filename unknown>:0 at Mono.Data.Sqlite.SqliteDataReader.GetString (Int32 i) [0x00000] in <filename unknown>:0 at Firefox.PlacesItemSource+<LoadPlaceItems>c__Iterator3.MoveNext () [0x00000] in <filename unknown>:0 at System.Collections.Generic.List`1[Firefox.PlaceItem].AddEnumerable (IEnumerable`1 enumerable) [0x00000] in <filename unknown>:0 at System.Collections.Generic.List`1[Firefox.PlaceItem]..ctor (IEnumerable`1 collection) [0x00000] in <filename unknown>:0 at System.Linq.Enumerable.ToArray[PlaceItem] (IEnumerable`1 source) [0x00000] in <filename unknown>:0 at Firefox.PlacesItemSource.UpdateItems () [0x00000] in <filename unknown>:0 at Do.Universe.Safe.SafeItemSource.UpdateItems () [0x00000] in <filename unknown>:0 . Do.Universe.Linux.GNOMESpecialLocationsItemSource "GNOME Special Locations" encountered an error in UpdateItems: System.IO.FileNotFoundException: Could not find file "/root/.gtk-bookmarks". File name: '/root/.gtk-bookmarks' at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, Boolean anonymous, FileOptions options) [0x00000] in <filename unknown>:0 at System.IO.FileStream..ctor (System.String path, FileMode mode, FileAccess access, FileShare share) [0x00000] in <filename unknown>:0 at (wrapper remoting-invoke-with-check) System.IO.FileStream:.ctor (string,System.IO.FileMode,System.IO.FileAccess,System.IO.FileShare) at System.IO.File.OpenRead (System.String path) [0x00000] in <filename unknown>:0 at System.IO.StreamReader..ctor (System.String path, System.Text.Encoding encoding, Boolean detectEncodingFromByteOrderMarks, Int32 bufferSize) [0x00000] in <filename unknown>:0 at System.IO.StreamReader..ctor (System.String path) [0x00000] in <filename unknown>:0 at (wrapper remoting-invoke-with-check) System.IO.StreamReader:.ctor (string) at Do.Universe.Linux.GNOMESpecialLocationsItemSource+<ReadBookmarkItems>c__Iterator3.MoveNext () [0x00000] in <filename unknown>:0 at Do.Universe.Linux.GNOMESpecialLocationsItemSource.UpdateItems () [0x00000] in <filename unknown>:0 at Do.Universe.Safe.SafeItemSource.UpdateItems () [0x00000] in <filename unknown>:0 . It stops when I try my key combination, ctrl-alt-. It does not pop up though.

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• Metro: Introduction to the WinJS ListView Control

  - by Stephen.Walther

  The goal of this blog entry is to provide a quick introduction to the ListView control – just the bare minimum that you need to know to start using the control. When building Metro style applications using JavaScript, the ListView control is the primary control that you use for displaying lists of items. For example, if you are building a product catalog app, then you can use the ListView control to display the list of products. The ListView control supports several advanced features that I plan to discuss in future blog entries. For example, you can group the items in a ListView, you can create master/details views with a ListView, and you can efficiently work with large sets of items with a ListView. In this blog entry, we’ll keep things simple and focus on displaying a list of products. There are three things that you need to do in order to display a list of items with a ListView: Create a data source Create an Item Template Declare the ListView Creating the ListView Data Source The first step is to create (or retrieve) the data that you want to display with the ListView. In most scenarios, you will want to bind a ListView to a WinJS.Binding.List object. The nice thing about the WinJS.Binding.List object is that it enables you to take a standard JavaScript array and convert the array into something that can be bound to the ListView. It doesn’t matter where the JavaScript array comes from. It could be a static array that you declare or you could retrieve the array as the result of an Ajax call to a remote server. The following JavaScript file – named products.js – contains a list of products which can be bound to a ListView. (function () { "use strict"; var products = new WinJS.Binding.List([ { name: "Milk", price: 2.44 }, { name: "Oranges", price: 1.99 }, { name: "Wine", price: 8.55 }, { name: "Apples", price: 2.44 }, { name: "Steak", price: 1.99 }, { name: "Eggs", price: 2.44 }, { name: "Mushrooms", price: 1.99 }, { name: "Yogurt", price: 2.44 }, { name: "Soup", price: 1.99 }, { name: "Cereal", price: 2.44 }, { name: "Pepsi", price: 1.99 } ]); WinJS.Namespace.define("ListViewDemos", { products: products }); })(); The products variable represents a WinJS.Binding.List object. This object is initialized with a plain-old JavaScript array which represents an array of products. To avoid polluting the global namespace, the code above uses the module pattern and exposes the products using a namespace. The list of products is exposed to the world as ListViewDemos.products. To learn more about the module pattern and namespaces in WinJS, see my earlier blog entry: http://stephenwalther.com/blog/archive/2012/02/22/metro-namespaces-and-modules.aspx Creating the ListView Item Template The ListView control does not know how to render anything. It doesn’t know how you want each list item to appear. To get the ListView control to render something useful, you must create an Item Template. Here’s what our template for rendering an individual product looks like: <div id="productTemplate" data-win-control="WinJS.Binding.Template"> <div class="product"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> </div> This template displays the product name and price from the data source. Normally, you will declare your template in the same file as you declare the ListView control. In our case, both the template and ListView are declared in the default.html file. To learn more about templates, see my earlier blog entry: http://stephenwalther.com/blog/archive/2012/02/27/metro-using-templates.aspx Declaring the ListView The final step is to declare the ListView control in a page. Here’s the markup for declaring a ListView: <div data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource:ListViewDemos.products.dataSource, itemTemplate:select('#productTemplate') }"> </div> You declare a ListView by adding the data-win-control to an HTML DIV tag. The data-win-options attribute is used to set two properties of the ListView. The ListView is associated with its data source with the itemDataSource property. Notice that the data source is ListViewDemos.products.dataSource and not just ListViewDemos.products. You need to associate the ListView with the dataSoure property. The ListView is associated with its item template with the help of the itemTemplate property. The ID of the item template — #productTemplate – is used to select the template from the page. Here’s what the complete version of the default.html page looks like: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>ListViewDemos</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- ListViewDemos references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script src="/js/products.js" type="text/javascript"></script> <style type="text/css"> .product { width: 200px; height: 100px; border: white solid 1px; } </style> </head> <body> <div id="productTemplate" data-win-control="WinJS.Binding.Template"> <div class="product"> <span data-win-bind="innerText:name"></span> <span data-win-bind="innerText:price"></span> </div> </div> <div data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource:ListViewDemos.products.dataSource, itemTemplate:select('#productTemplate') }"> </div> </body> </html> Notice that the page above includes a reference to the products.js file: <script src=”/js/products.js” type=”text/javascript”></script> The page above also contains a Template control which contains the ListView item template. Finally, the page includes the declaration of the ListView control. Summary The goal of this blog entry was to describe the minimal set of steps which you must complete to use the WinJS ListView control to display a simple list of items. You learned how to create a data source, declare an item template, and declare a ListView control.

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• C#: LINQ vs foreach - Round 1.

  - by James Michael Hare

  So I was reading Peter Kellner's blog entry on Resharper 5.0 and its LINQ refactoring and thought that was very cool.  But that raised a point I had always been curious about in my head -- which is a better choice: manual foreach loops or LINQ?    The answer is not really clear-cut.  There are two sides to any code cost arguments: performance and maintainability.  The first of these is obvious and quantifiable.  Given any two pieces of code that perform the same function, you can run them side-by-side and see which piece of code performs better.   Unfortunately, this is not always a good measure.  Well written assembly language outperforms well written C++ code, but you lose a lot in maintainability which creates a big techncial debt load that is hard to offset as the application ages.  In contrast, higher level constructs make the code more brief and easier to understand, hence reducing technical cost.   Now, obviously in this case we're not talking two separate languages, we're comparing doing something manually in the language versus using a higher-order set of IEnumerable extensions that are in the System.Linq library.   Well, before we discuss any further, let's look at some sample code and the numbers.  First, let's take a look at the for loop and the LINQ expression.  This is just a simple find comparison:       // find implemented via LINQ     public static bool FindViaLinq(IEnumerable<int> list, int target)     {         return list.Any(item => item == target);     }         // find implemented via standard iteration     public static bool FindViaIteration(IEnumerable<int> list, int target)     {         foreach (var i in list)         {             if (i == target)             {                 return true;             }         }           return false;     }   Okay, looking at this from a maintainability point of view, the Linq expression is definitely more concise (8 lines down to 1) and is very readable in intention.  You don't have to actually analyze the behavior of the loop to determine what it's doing.   So let's take a look at performance metrics from 100,000 iterations of these methods on a List<int> of varying sizes filled with random data.  For this test, we fill a target array with 100,000 random integers and then run the exact same pseudo-random targets through both searches.                       List<T> On 100,000 Iterations     Method      Size     Total (ms)  Per Iteration (ms)  % Slower     Any         10       26          0.00046             30.00%     Iteration   10       20          0.00023             -     Any         100      116         0.00201             18.37%     Iteration   100      98          0.00118             -     Any         1000     1058        0.01853             16.78%     Iteration   1000     906         0.01155             -     Any         10,000   10,383      0.18189             17.41%     Iteration   10,000   8843        0.11362             -     Any         100,000  104,004     1.8297              18.27%     Iteration   100,000  87,941      1.13163             -   The LINQ expression is running about 17% slower for average size collections and worse for smaller collections.  Presumably, this is due to the overhead of the state machine used to track the iterators for the yield returns in the LINQ expressions, which seems about right in a tight loop such as this.   So what about other LINQ expressions?  After all, Any() is one of the more trivial ones.  I decided to try the TakeWhile() algorithm using a Count() to get the position stopped like the sample Pete was using in his blog that Resharper refactored for him into LINQ:       // Linq form     public static int GetTargetPosition1(IEnumerable<int> list, int target)     {         return list.TakeWhile(item => item != target).Count();     }       // traditionally iterative form     public static int GetTargetPosition2(IEnumerable<int> list, int target)     {         int count = 0;           foreach (var i in list)         {             if(i == target)             {                 break;             }               ++count;         }           return count;     }   Once again, the LINQ expression is much shorter, easier to read, and should be easier to maintain over time, reducing the cost of technical debt.  So I ran these through the same test data:                       List<T> On 100,000 Iterations     Method      Size     Total (ms)  Per Iteration (ms)  % Slower     TakeWhile   10       41          0.00041             128%     Iteration   10       18          0.00018             -     TakeWhile   100      171         0.00171             88%     Iteration   100      91          0.00091             -     TakeWhile   1000     1604        0.01604             94%     Iteration   1000     825         0.00825             -     TakeWhile   10,000   15765       0.15765             92%     Iteration   10,000   8204        0.08204             -     TakeWhile   100,000  156950      1.5695              92%     Iteration   100,000  81635       0.81635             -     Wow!  I expected some overhead due to the state machines iterators produce, but 90% slower?  That seems a little heavy to me.  So then I thought, well, what if TakeWhile() is not the right tool for the job?  The problem is TakeWhile returns each item for processing using yield return, whereas our for-loop really doesn't care about the item beyond using it as a stop condition to evaluate. So what if that back and forth with the iterator state machine is the problem?  Well, we can quickly create an (albeit ugly) lambda that uses the Any() along with a count in a closure (if a LINQ guru knows a better way PLEASE let me know!), after all , this is more consistent with what we're trying to do, we're trying to find the first occurence of an item and halt once we find it, we just happen to be counting on the way.  This mostly matches Any().       // a new method that uses linq but evaluates the count in a closure.     public static int TakeWhileViaLinq2(IEnumerable<int> list, int target)     {         int count = 0;         list.Any(item =>             {                 if(item == target)                 {                     return true;                 }                   ++count;                 return false;             });         return count;     }     Now how does this one compare?                         List<T> On 100,000 Iterations     Method         Size     Total (ms)  Per Iteration (ms)  % Slower     TakeWhile      10       41          0.00041             128%     Any w/Closure  10       23          0.00023             28%     Iteration      10       18          0.00018             -     TakeWhile      100      171         0.00171             88%     Any w/Closure  100      116         0.00116             27%     Iteration      100      91          0.00091             -     TakeWhile      1000     1604        0.01604             94%     Any w/Closure  1000     1101        0.01101             33%     Iteration      1000     825         0.00825             -     TakeWhile      10,000   15765       0.15765             92%     Any w/Closure  10,000   10802       0.10802             32%     Iteration      10,000   8204        0.08204             -     TakeWhile      100,000  156950      1.5695              92%     Any w/Closure  100,000  108378      1.08378             33%     Iteration      100,000  81635       0.81635             -     Much better!  It seems that the overhead of TakeAny() returning each item and updating the state in the state machine is drastically reduced by using Any() since Any() iterates forward until it finds the value we're looking for -- for the task we're attempting to do.   So the lesson there is, make sure when you use a LINQ expression you're choosing the best expression for the job, because if you're doing more work than you really need, you'll have a slower algorithm.  But this is true of any choice of algorithm or collection in general.     Even with the Any() with the count in the closure it is still about 30% slower, but let's consider that angle carefully.  For a list of 100,000 items, it was the difference between 1.01 ms and 0.82 ms roughly in a List<T>.  That's really not that bad at all in the grand scheme of things.  Even running at 90% slower with TakeWhile(), for the vast majority of my projects, an extra millisecond to save potential errors in the long term and improve maintainability is a small price to pay.  And if your typical list is 1000 items or less we're talking only microseconds worth of difference.   It's like they say: 90% of your performance bottlenecks are in 2% of your code, so over-optimizing almost never pays off.  So personally, I'll take the LINQ expression wherever I can because they will be easier to read and maintain (thus reducing technical debt) and I can rely on Microsoft's development to have coded and unit tested those algorithm fully for me instead of relying on a developer to code the loop logic correctly.   If something's 90% slower, yes, it's worth keeping in mind, but it's really not until you start get magnitudes-of-order slower (10x, 100x, 1000x) that alarm bells should really go off.  And if I ever do need that last millisecond of performance?  Well then I'll optimize JUST THAT problem spot.  To me it's worth it for the readability, speed-to-market, and maintainability.

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• Upgrading from 12.10 to 13.04 -> dpkg: error processing sudo (--configure)

  - by Korrigan Nagirrok

  Here's the deal and reason I'm asking for your help. Last night I went on upgrading my Xubuntu 12.10 installation to 13.04, so at tty1 I run the command sudo do-release-upgrade and everything seemed to went well except that after rebooting and when I run sudo apt-get update && sudo apt-get upgrade I get this error: sudo apt-get update && sudo apt-get upgrade Hit http://pt.archive.ubuntu.com raring Release.gpg Hit http://pt.archive.ubuntu.com raring-updates Release.gpg Hit http://dl.google.com stable Release.gpg Hit http://pt.archive.ubuntu.com raring-backports Release.gpg Hit http://pt.archive.ubuntu.com raring Release Hit http://archive.canonical.com raring Release.gpg Hit http://ppa.launchpad.net raring Release.gpg Hit http://pt.archive.ubuntu.com raring-updates Release Hit http://extras.ubuntu.com raring Release.gpg Hit http://pt.archive.ubuntu.com raring-backports Release Hit http://dl.google.com stable Release Hit http://pt.archive.ubuntu.com raring/main Sources Hit http://pt.archive.ubuntu.com raring/restricted Sources Hit http://extras.ubuntu.com raring Release Hit http://archive.canonical.com raring Release Hit http://ppa.launchpad.net raring Release.gpg Hit http://pt.archive.ubuntu.com raring/universe Sources Hit http://pt.archive.ubuntu.com raring/multiverse Sources Hit http://dl.google.com stable/main i386 Packages Get:1 http://security.ubuntu.com raring-security Release.gpg [933 B] Hit http://pt.archive.ubuntu.com raring/main i386 Packages Hit http://extras.ubuntu.com raring/main Sources Hit http://ppa.launchpad.net raring Release Hit http://archive.canonical.com raring/partner i386 Packages Hit http://pt.archive.ubuntu.com raring/restricted i386 Packages Hit http://pt.archive.ubuntu.com raring/universe i386 Packages Hit http://extras.ubuntu.com raring/main i386 Packages Hit http://pt.archive.ubuntu.com raring/multiverse i386 Packages Hit http://ppa.launchpad.net raring Release Hit http://pt.archive.ubuntu.com raring/main Translation-en Hit http://ppa.launchpad.net raring/main Sources Hit http://ppa.launchpad.net raring/main i386 Packages Hit http://pt.archive.ubuntu.com raring/multiverse Translation-en Hit http://pt.archive.ubuntu.com raring/restricted Translation-en Hit http://pt.archive.ubuntu.com raring/universe Translation-en Hit http://pt.archive.ubuntu.com raring-updates/main Sources Hit http://pt.archive.ubuntu.com raring-updates/restricted Sources Hit http://ppa.launchpad.net raring/main Sources Hit http://pt.archive.ubuntu.com raring-updates/universe Sources Hit http://pt.archive.ubuntu.com raring-updates/multiverse Sources Hit http://pt.archive.ubuntu.com raring-updates/main i386 Packages Hit http://ppa.launchpad.net raring/main i386 Packages Hit http://pt.archive.ubuntu.com raring-updates/restricted i386 Packages Hit http://pt.archive.ubuntu.com raring-updates/universe i386 Packages Hit http://pt.archive.ubuntu.com raring-updates/multiverse i386 Packages Ign http://dl.google.com stable/main Translation-en_US Hit http://pt.archive.ubuntu.com raring-updates/main Translation-en Ign http://archive.canonical.com raring/partner Translation-en_US Ign http://extras.ubuntu.com raring/main Translation-en_US Ign http://dl.google.com stable/main Translation-en Ign http://archive.canonical.com raring/partner Translation-en Hit http://pt.archive.ubuntu.com raring-updates/multiverse Translation-en Ign http://extras.ubuntu.com raring/main Translation-en Hit http://pt.archive.ubuntu.com raring-updates/restricted Translation-en Hit http://pt.archive.ubuntu.com raring-updates/universe Translation-en Hit http://pt.archive.ubuntu.com raring-backports/main Sources Hit http://pt.archive.ubuntu.com raring-backports/restricted Sources Hit http://pt.archive.ubuntu.com raring-backports/universe Sources Hit http://pt.archive.ubuntu.com raring-backports/multiverse Sources Hit http://pt.archive.ubuntu.com raring-backports/main i386 Packages Hit http://pt.archive.ubuntu.com raring-backports/restricted i386 Packages Hit http://pt.archive.ubuntu.com raring-backports/universe i386 Packages Hit http://pt.archive.ubuntu.com raring-backports/multiverse i386 Packages Hit http://pt.archive.ubuntu.com raring-backports/main Translation-en Hit http://pt.archive.ubuntu.com raring-backports/multiverse Translation-en Get:2 http://security.ubuntu.com raring-security Release [40.8 kB] Hit http://pt.archive.ubuntu.com raring-backports/restricted Translation-en Hit http://pt.archive.ubuntu.com raring-backports/universe Translation-en Ign http://ppa.launchpad.net raring/main Translation-en_US Ign http://ppa.launchpad.net raring/main Translation-en Get:3 http://security.ubuntu.com raring-security/main Sources [2,109 B] Ign http://ppa.launchpad.net raring/main Translation-en_US Ign http://ppa.launchpad.net raring/main Translation-en Get:4 http://security.ubuntu.com raring-security/restricted Sources [14 B] Get:5 http://security.ubuntu.com raring-security/universe Sources [14 B] Get:6 http://security.ubuntu.com raring-security/multiverse Sources [14 B] Get:7 http://security.ubuntu.com raring-security/main i386 Packages [3,670 B] Get:8 http://security.ubuntu.com raring-security/restricted i386 Packages [14 B] Get:9 http://security.ubuntu.com raring-security/universe i386 Packages [2,824 B] Get:10 http://security.ubuntu.com raring-security/multiverse i386 Packages [14 B] Ign http://pt.archive.ubuntu.com raring/main Translation-en_US Ign http://pt.archive.ubuntu.com raring/multiverse Translation-en_US Ign http://pt.archive.ubuntu.com raring/restricted Translation-en_US Ign http://pt.archive.ubuntu.com raring/universe Translation-en_US Ign http://pt.archive.ubuntu.com raring-updates/main Translation-en_US Ign http://pt.archive.ubuntu.com raring-updates/multiverse Translation-en_US Hit http://security.ubuntu.com raring-security/main Translation-en Ign http://pt.archive.ubuntu.com raring-updates/restricted Translation-en_US Ign http://pt.archive.ubuntu.com raring-updates/universe Translation-en_US Ign http://pt.archive.ubuntu.com raring-backports/main Translation-en_US Ign http://pt.archive.ubuntu.com raring-backports/multiverse Translation-en_US Ign http://pt.archive.ubuntu.com raring-backports/restricted Translation-en_US Hit http://security.ubuntu.com raring-security/multiverse Translation-en Ign http://pt.archive.ubuntu.com raring-backports/universe Translation-en_US Hit http://security.ubuntu.com raring-security/restricted Translation-en Hit http://security.ubuntu.com raring-security/universe Translation-en Ign http://security.ubuntu.com raring-security/main Translation-en_US Ign http://security.ubuntu.com raring-security/multiverse Translation-en_US Ign http://security.ubuntu.com raring-security/restricted Translation-en_US Ign http://security.ubuntu.com raring-security/universe Translation-en_US Fetched 50.4 kB in 6s (7,454 B/s) Reading package lists... Done Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 2 not fully installed or removed. Need to get 0 B/373 kB of archives. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]? Y dpkg: error processing sudo (--configure): Package is in a very bad inconsistent state - you should reinstall it before attempting configuration. No apport report written because MaxReports is reached already dpkg: dependency problems prevent configuration of ubuntu-minimal: ubuntu-minimal depends on sudo; however: Package sudo is not configured yet. dpkg: error processing ubuntu-minimal (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already Errors were encountered while processing: sudo ubuntu-minimal E: Sub-process /usr/bin/dpkg returned an error code (1) I've tried everything I thought logical, like sudo dpkg --configure -a dpkg: error processing sudo (--configure): Package is in a very bad inconsistent state - you should reinstall it before attempting configuration. dpkg: dependency problems prevent configuration of ubuntu-minimal: ubuntu-minimal depends on sudo; however: Package sudo is not configured yet. dpkg: error processing ubuntu-minimal (--configure): dependency problems - leaving unconfigured Errors were encountered while processing: sudo ubuntu-minimal sudo apt-get install -f Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 2 not fully installed or removed. Need to get 0 B/373 kB of archives. After this operation, 0 B of additional disk space will be used. dpkg: error processing sudo (--configure): Package is in a very bad inconsistent state - you should reinstall it before attempting configuration. dpkg: dependency problems prevent configuration of ubuntu-minimal: ubuntu-minimal depends on sudo; however: Package sudo is not configured yet. dpkg: error processing ubuntu-minimal (--configure): dependency problems - leaving unconfigured No apport report written because MaxReports is reached already No apport report written because MaxReports is reached already Errors were encountered while processing: sudo ubuntu-minimal E: Sub-process /usr/bin/dpkg returned an error code (1) Can someone help me, please. Edit: Here's some more info that could be of help for anyone. The output of apt-cache policy linux-image-generic-pae linux-generic-pae is linux-image-generic-pae: Installed: (none) Candidate: 3.8.0.19.35 Version table: 3.8.0.19.35 0 500 http://pt.archive.ubuntu.com/ubuntu/ raring/main i386 Packages linux-generic-pae: Installed: (none) Candidate: 3.8.0.19.35 Version table: 3.8.0.19.35 0 500 http://pt.archive.ubuntu.com/ubuntu/ raring/main i386 Packages

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• Charms and the App Bar

  - by Dennis Vroegop

  Ok. I admit. I made a mistake in the last post about our planespotter app. I have dedicated a full part of the hub to Social. I also had a section called Friends but that made sense since I said that “Friends” is a special group of people that connect to each other through our app and only our app. Social however is sharing our spots with Twitter, Facebook and so on. Now, we could write that functionality in our app in a different section but there is one small problem with that: users don’t expect that. Ok, I admit. The mistake was quite deliberate to give me an excuse to write this part. But still: the mistake is one I see a lot. People are trying to do stuff in their application that they shouldn’t be doing. This always strike me as slightly odd: why do some work when others have already done it for you and you can just use it? After all: good developers are lazy (lazy people will always try to find the easiest way to do something and in development land this usually means the cleanest and best to support way…) So. What is that part that Microsoft has done for us and we don’t have to do ourselves? The answer lies on the right hand of your Win8 screen: This is a screenshot of my tablet (as you can see I am writing this right now….) When I swipe my finger from out of the screen on the right inside the screen (or move the mouse to the upper right corner) this menu will appear. Next to settings and the start menu button we’ll find the Search and the Share charms. These are two ways that your app can share the information it contains with the rest of the world, or at least: the rest of your system. So don’t write a Search feature in your app. Don’t write a Share feature in your app. It’s here already. Users, once they are used to Windows 8, will use that feature and expect it to work. If it doesn’t, they won’t like your app and you can kiss you dreams of everlasting fame goodbye. So use these two. What are they? Well, simply they are parts of a contract. In your app you say somewhere in code that you are supporting Search and Share. So when the user selects Share the system will interrogate the current app in the foreground if it supports this feature. Your app will say “But why, yes, I do!” Then the system will ask the app “Ok then, wisecrack, then share!” and you will have to provide the system with some information about the format. Other applications have subscribed to be at the receiving end of the Share contract. They have told the system that they support Sharing (receiving) and which formats they understand. If one or more of them support the formats you specify, the user will see them. The user clicks / taps on the app of their choice and data is moved from your app to the new one. So if you say you support Facebook and Twitter users can post data from your app to these networks by selecting Share. The same applies to Search. Don’t make a “search” button in your app but use the contract to tell the system that you support search and use that instead. Users will be grateful (remember that bar with men/women/creatures that are waiting for you?) The more and more people get to know Windows 8, the more they will use this. And if you are one of the people who wrote an app that helped them learn the system, well, that’s even better. So. We don’t have a Share or a Search button. We do have other buttons. Most important: we probably need a “New Spot” button. And a “Filter” might be useful. Or someway to open the camera so you can add a picture to the spot. Where will be put those? The answer is the “Appbar” . This is a application / context aware menu that slides up from the bottom of the screen when you move your finger / mouse from below the screen into it. From above downwards works just as well. Here you see an example of the appbar from the People app. (click on it for a larger version). This appears whenever you slide your finger up from below of down from above. This is where you put your commands. Remember, this is context aware so this menu will change when you are in different parts of your app or when you have selected different items. There are a few conventions when you create this appbar. First, the items on the right are “General” items, meaning they have little to do with what is on the screen right now. I think this would be a great place to add our “New Spot” icon. On the far left are items associated with the current selected item or screen. So if you have a spot selected, the button for Add Photo should be visible here and on the left hand side. Not everything is as clear as this, but this is what you should strive for. Group items together. And please note: this is the only place in Metro design where we are allowed to use lines as separators. So when you want to separate a group of icons from another group, add a line. Also note the simplicity of the buttons. No colors, no lights or shadows, no 3D. After a couple of years of fancy almost realistic looking icons people have finally decided that hey, this is a virtual world: it’s ok to look virtual as well. So make things as readable and clear as possible and don’t try to duplicate nature. It’s all about the information, remember? (If you don’t remember I’d like to point you to a older blog post of mine about the what and why of Metro). So.. think about the buttons a bit and think about Share and Search. What will you put there? Remember: this is the way the users interact with your apps and while you shouldn’t judge a book by its covers when it comes to people, this isn’t entirely so when it comes to apps. People DO judge an app by its looks and the way it feels. Take advantage of that. History has learned that a crappy app with a GREAT user interface gets better reviews than a GREAT app with a lousy UI… I know: developers will find this extremely unfair but that’s the world we live in (No, I am not saying you should deliver rubbish apps). Next time: we’ll start by building the darn thing!

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• Is RTD Stateless or Stateful?

  - by [email protected]

  Yes.   A stateless service is one where each request is an independent transaction that can be processed by any of the servers in a cluster.  A stateful service is one where state is kept in a server's memory from transaction to transaction, thus necessitating the proper routing of requests to the right server. The main advantage of stateless systems is simplicity of design. The main advantage of stateful systems is performance. I'm often asked whether RTD is a stateless or stateful service, so I wanted to clarify this issue in depth so that RTD's architecture will be properly understood. The short answer is: "RTD can be configured as a stateless or stateful service." The performance difference between stateless and stateful systems can be very significant, and while in a call center implementation it may be reasonable to use a pure stateless configuration, a web implementation that produces thousands of requests per second is practically impossible with a stateless configuration. RTD's performance is orders of magnitude better than most competing systems. RTD was architected from the ground up to achieve this performance. Features like automatic and dynamic compression of prediction models, automatic translation of metadata to machine code, lack of interpreted languages, and separation of model building from decisioning contribute to achieving this performance level. Because  of this focus on performance we decided to have RTD's default configuration work in a stateful manner. By being stateful RTD requests are typically handled in a few milliseconds when repeated requests come to the same session. Now, those readers that have participated in implementations of RTD know that RTD's architecture is also focused on reducing Total Cost of Ownership (TCO) with features like automatic model building, automatic time windows, automatic maintenance of database tables, automatic evaluation of data mining models, automatic management of models partitioned by channel, geography, etcetera, and hot swapping of configurations. How do you reconcile the need for a low TCO and the need for performance? How do you get the performance of a stateful system with the simplicity of a stateless system? The answer is that you make the system behave like a stateless system to the exterior, but you let it automatically take advantage of situations where being stateful is better. For example, one of the advantages of stateless systems is that you can route a message to any server in a cluster, without worrying about sending it to the same server that was handling the session in previous messages. With an RTD stateful configuration you can still route the message to any server in the cluster, so from the point of view of the configuration of other systems, it is the same as a stateless service. The difference though comes in performance, because if the message arrives to the right server, RTD can serve it without any external access to the session's state, thus tremendously reducing processing time. In typical implementations it is not rare to have high percentages of messages routed directly to the right server, while those that are not, are easily handled by forwarding the messages to the right server. This architecture usually provides the best of both worlds with performance and simplicity of configuration.   Configuring RTD as a pure stateless service A pure stateless configuration requires session data to be persisted at the end of handling each and every message and reloading that data at the beginning of handling any new message. This is of course, the root of the inefficiency of these configurations. This is also the reason why many "stateless" implementations actually do keep state to take advantage of a request coming back to the same server. Nevertheless, if the implementation requires a pure stateless decision service, this is easy to configure in RTD. The way to do it is: Mark every Integration Point to Close the session at the end of processing the message In the Session entity persist the session data on closing the session In the session entity check if a persisted version exists and load it An excellent solution for persisting the session data is Oracle Coherence, which provides a high performance, distributed cache that minimizes the performance impact of persisting and reloading the session. Alternatively, the session can be persisted to a local database. An interesting feature of the RTD stateless configuration is that it can cope with serializing concurrent requests for the same session. For example, if a web page produces two requests to the decision service, these requests could come concurrently to the decision services and be handled by different servers. Most stateless implementation would have the two requests step onto each other when saving the state, or fail one of the messages. When properly configured, RTD will make one message wait for the other before processing.   A Word on Context Using the context of a customer interaction typically significantly increases lift. For example, offer success in a call center could double if the context of the call is taken into account. For this reason, it is important to utilize the contextual information in decision making. To make the contextual information available throughout a session it needs to be persisted. When there is a well defined owner for the information then there is no problem because in case of a session restart, the information can be easily retrieved. If there is no official owner of the information, then RTD can be configured to persist this information.   Once again, RTD provides flexibility to ensure high performance when it is adequate to allow for some loss of state in the rare cases of server failure. For example, in a heavy use web site that serves 1000 pages per second the navigation history may be stored in the in memory session. In such sites it is typical that there is no OLTP that stores all the navigation events, therefore if an RTD server were to fail, it would be possible for the navigation to that point to be lost (note that a new session would be immediately established in one of the other servers). In most cases the loss of this navigation information would be acceptable as it would happen rarely. If it is desired to save this information, RTD would persist it every time the visitor navigates to a new page. Note that this practice is preferred whether RTD is configured in a stateless or stateful manner.  

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• Working With Extended Events

  - by Fatherjack

  SQL Server 2012 has made working with Extended Events (XE) pretty simple when it comes to what sessions you have on your servers and what options you have selected and so forth but if you are like me then you still have some SQL Server instances that are 2008 or 2008 R2. For those servers there is no built-in way to view the Extended Event sessions in SSMS. I keep coming up against the same situations – Where are the xel log files? What events, actions or predicates are set for the events on the server? What sessions are there on the server already? I got tired of this being a perpetual question and wrote some TSQL to save as a snippet in SQL Prompt so that these details are permanently only a couple of clicks away. First, some history. If you just came here for the code skip down a few paragraphs and it’s all there. If you want a little time to reminisce about SQL Server then stick with me through the next paragraph or two. We are in a bit of a cross-over period currently, there are many versions of SQL Server but I would guess that SQL Server 2008, 2008 R2 and 2012 comprise the majority of installations. With each of these comes a set of management tools, of which SQL Server Management Studio (SSMS) is one. In 2008 and 2008 R2 Extended Events made their first appearance and there was no way to work with them in the SSMS interface. At some point the Extended Events guru Jonathan Kehayias (http://www.sqlskills.com/blogs/jonathan/) created the SQL Server 2008 Extended Events SSMS Addin which is really an excellent tool to ease XE session administration. This addin will install in SSMS 2008 or 2008R2 but not SSMS 2012. If you use a compatible version of SSMS then I wholly recommend downloading and using it to make your work with XE much easier. If you have SSMS 2012 installed, and there is no reason not to as it will let you work with all versions of SQL Server, then you cannot install this addin. If you are working with SQL Server 2012 then SSMS 2012 has built in functionality to manage XE sessions – this functionality does not apply for 2008 or 2008 R2 instances though. This means you are somewhat restricted and have to use TSQL to manage XE sessions on older versions of SQL Server. OK, those of you that skipped ahead for the code, you need to start from here: So, you are working with SSMS 2012 but have a SQL Server that is an earlier version that needs an XE session created or you think there is a session created but you aren’t sure, or you know it’s there but can’t remember if it is running and where the output is going. How do you find out? Well, none of the information is hidden as such but it is a bit of a wrangle to locate it and it isn’t a lot of code that is unlikely to remain in your memory. I have created two pieces of code. The first examines the SYS.Server_Event_… management views in combination with the SYS.DM_XE_… management views to give the name of all sessions that exist on the server, regardless of whether they are running or not and two pieces of TSQL code. One piece will alter the state of the session: if the session is running then the code will stop the session if executed and vice versa. The other piece of code will drop the selected session. If the session is running then the code will stop it first. Do not execute the DROP code unless you are sure you have the Create code to hand. It will be dropped from the server without a second chance to change your mind. /**************************************************************/ /***   To locate and describe event sessions on a server    ***/ /***                                                        ***/ /***   Generates TSQL to start/stop/drop sessions           ***/ /***                                                        ***/ /***        Jonathan Allen - @fatherjack                    ***/ /***                 June 2013                                ***/ /***                                                        ***/ /**************************************************************/ SELECT  [EES].[name] AS [Session Name - all sessions] ,         CASE WHEN [MXS].[name] IS NULL THEN ISNULL([MXS].[name], 'Stopped')              ELSE 'Running'         END AS SessionState ,         CASE WHEN [MXS].[name] IS NULL              THEN ISNULL([MXS].[name],                          'ALTER EVENT SESSION [' + [EES].[name]                          + '] ON SERVER STATE = START;')              ELSE 'ALTER EVENT SESSION [' + [EES].[name]                   + '] ON SERVER STATE = STOP;'         END AS ALTER_SessionState ,         CASE WHEN [MXS].[name] IS NULL              THEN ISNULL([MXS].[name],                          'DROP EVENT SESSION [' + [EES].[name]                          + '] ON SERVER; -- This WILL drop the session. It will no longer exist. Don't do it unless you are certain you can recreate it if you need it.')              ELSE 'ALTER EVENT SESSION [' + [EES].[name]                   + '] ON SERVER STATE = STOP; ' + CHAR(10)                   + '-- DROP EVENT SESSION [' + [EES].[name]                   + '] ON SERVER; -- This WILL stop and drop the session. It will no longer exist. Don't do it unless you are certain you can recreate it if you need it.'         END AS DROP_Session FROM    [sys].[server_event_sessions] AS EES         LEFT JOIN [sys].[dm_xe_sessions] AS MXS ON [EES].[name] = [MXS].[name] WHERE   [EES].[name] NOT IN ( 'system_health', 'AlwaysOn_health' ) ORDER BY SessionState GO I have excluded the system_health and AlwaysOn sessions as I don’t want to accidentally execute the drop script for these sessions that are created as part of the SQL Server installation. It is possible to recreate the sessions but that is a whole lot of aggravation I’d rather avoid. The second piece of code gathers details of running XE sessions only and provides information on the Events being collected, any predicates that are set on those events, the actions that are set to be collected, where the collected information is being logged and if that logging is to a file target, where that file is located. /**********************************************/ /***    Running Session summary                ***/ /***                                        ***/ /***    Details key values of XE sessions     ***/ /***    that are in a running state            ***/ /***                                        ***/ /***        Jonathan Allen - @fatherjack    ***/ /***        June 2013                        ***/ /***                                        ***/ /**********************************************/ SELECT  [EES].[name] AS [Session Name - running sessions] ,         [EESE].[name] AS [Event Name] ,         COALESCE([EESE].[predicate], 'unfiltered') AS [Event Predicate Filter(s)] ,         [EESA].[Action] AS [Event Action(s)] ,         [EEST].[Target] AS [Session Target(s)] ,         ISNULL([EESF].[value], 'No file target in use') AS [File_Target_UNC] -- select * FROM    [sys].[server_event_sessions] AS EES         INNER JOIN [sys].[dm_xe_sessions] AS MXS ON [EES].[name] = [MXS].[name]         INNER JOIN [sys].[server_event_session_events] AS [EESE] ON [EES].[event_session_id] = [EESE].[event_session_id]         LEFT JOIN [sys].[server_event_session_fields] AS EESF ON ( [EES].[event_session_id] = [EESF].[event_session_id]                                                               AND [EESF].[name] = 'filename'                                                               )         CROSS APPLY ( SELECT    STUFF(( SELECT  ', ' + sest.name                                         FROM    [sys].[server_event_session_targets]                                                 AS SEST                                         WHERE   [EES].[event_session_id] = [SEST].[event_session_id]                                       FOR                                         XML PATH('')                                       ), 1, 2, '') AS [Target]                     ) AS EEST         CROSS APPLY ( SELECT    STUFF(( SELECT  ', ' + [sesa].NAME                                         FROM    [sys].[server_event_session_actions]                                                 AS sesa                                         WHERE   [sesa].[event_session_id] = [EES].[event_session_id]                                       FOR                                         XML PATH('')                                       ), 1, 2, '') AS [Action]                     ) AS EESA WHERE   [EES].[name] NOT IN ( 'system_health', 'AlwaysOn_health' ) /*Optional to exclude 'out-of-the-box' traces*/ I hope that these scripts are useful to you and I would be obliged if you would keep my name in the script comments. I have no problem with you using it in production or personal circumstances, however it has no warranty or guarantee. Don’t use it unless you understand it and are happy with what it is going to do. I am not ever responsible for the consequences of executing this script on your servers.

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• C#/.NET Little Wonders: Comparer&lt;T&gt;.Default

  - by James Michael Hare

  I’ve been working with a wonderful team on a major release where I work, which has had the side-effect of occupying most of my spare time preparing, testing, and monitoring.  However, I do have this Little Wonder tidbit to offer today. Introduction The IComparable<T> interface is great for implementing a natural order for a data type.  It’s a very simple interface with a single method: 1: public interface IComparer<in T> 2: { 3: // Compare two instances of same type. 4: int Compare(T x, T y); 5: }  So what do we expect for the integer return value?  It’s a pseudo-relative measure of the ordering of x and y, which returns an integer value in much the same way C++ returns an integer result from the strcmp() c-style string comparison function: If x == y, returns 0. If x > y, returns > 0 (often +1, but not guaranteed) If x < y, returns < 0 (often –1, but not guaranteed) Notice that the comparison operator used to evaluate against zero should be the same comparison operator you’d use as the comparison operator between x and y.  That is, if you want to see if x > y you’d see if the result > 0. The Problem: Comparing With null Can Be Messy This gets tricky though when you have null arguments.  According to the MSDN, a null value should be considered equal to a null value, and a null value should be less than a non-null value.  So taking this into account we’d expect this instead: If x == y (or both null), return 0. If x > y (or y only is null), return > 0. If x < y (or x only is null), return < 0. But here’s the problem – if x is null, what happens when we attempt to call CompareTo() off of x? 1: // what happens if x is null? 2: x.CompareTo(y); It’s pretty obvious we’ll get a NullReferenceException here.  Now, we could guard against this before calling CompareTo(): 1: int result; 2:  3: // first check to see if lhs is null. 4: if (x == null) 5: { 6: // if lhs null, check rhs to decide on return value. 7: if (y == null) 8: { 9: result = 0; 10: } 11: else 12: { 13: result = -1; 14: } 15: } 16: else 17: { 18: // CompareTo() should handle a null y correctly and return > 0 if so. 19: result = x.CompareTo(y); 20: } Of course, we could shorten this with the ternary operator (?:), but even then it’s ugly repetitive code: 1: int result = (x == null) 2: ? ((y == null) ? 0 : -1) 3: : x.CompareTo(y); Fortunately, the null issues can be cleaned up by drafting in an external Comparer.  The Soltuion: Comparer<T>.Default You can always develop your own instance of IComparer<T> for the job of comparing two items of the same type.  The nice thing about a IComparer is its is independent of the things you are comparing, so this makes it great for comparing in an alternative order to the natural order of items, or when one or both of the items may be null. 1: public class NullableIntComparer : IComparer<int?> 2: { 3: public int Compare(int? x, int? y) 4: { 5: return (x == null) 6: ? ((y == null) ? 0 : -1) 7: : x.Value.CompareTo(y); 8: } 9: }  Now, if you want a custom sort -- especially on large-grained objects with different possible sort fields -- this is the best option you have.  But if you just want to take advantage of the natural ordering of the type, there is an easier way.  If the type you want to compare already implements IComparable<T> or if the type is System.Nullable<T> where T implements IComparable, there is a class in the System.Collections.Generic namespace called Comparer<T> which exposes a property called Default that will create a singleton that represents the default comparer for items of that type.  For example: 1: // compares integers 2: var intComparer = Comparer<int>.Default; 3:  4: // compares DateTime values 5: var dateTimeComparer = Comparer<DateTime>.Default; 6:  7: // compares nullable doubles using the null rules! 8: var nullableDoubleComparer = Comparer<double?>.Default;  This helps you avoid having to remember the messy null logic and makes it to compare objects where you don’t know if one or more of the values is null. This works especially well when creating say an IComparer<T> implementation for a large-grained class that may or may not contain a field.  For example, let’s say you want to create a sorting comparer for a stock open price, but if the market the stock is trading in hasn’t opened yet, the open price will be null.  We could handle this (assuming a reasonable Quote definition) like: 1: public class Quote 2: { 3: // the opening price of the symbol quoted 4: public double? Open { get; set; } 5:  6: // ticker symbol 7: public string Symbol { get; set; } 8:  9: // etc. 10: } 11:  12: public class OpenPriceQuoteComparer : IComparer<Quote> 13: { 14: // Compares two quotes by opening price 15: public int Compare(Quote x, Quote y) 16: { 17: return Comparer<double?>.Default.Compare(x.Open, y.Open); 18: } 19: } Summary Defining a custom comparer is often needed for non-natural ordering or defining alternative orderings, but when you just want to compare two items that are IComparable<T> and account for null behavior, you can use the Comparer<T>.Default comparer generator and you’ll never have to worry about correct null value sorting again.     Technorati Tags: C#,.NET,Little Wonders,BlackRabbitCoder,IComparable,Comparer

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• Data Source Connection Pool Sizing

  - by Steve Felts

  Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} One of the most time-consuming procedures of a database application is establishing a connection. The connection pooling of the data source can be used to minimize this overhead.  That argues for using the data source instead of accessing the database driver directly. Configuring the size of the pool in the data source is somewhere between an art and science – this article will try to move it closer to science.  From the beginning, WLS data source has had an initial capacity and a maximum capacity configuration values.  When the system starts up and when it shrinks, initial capacity is used.  The pool can grow to maximum capacity.  Customers found that they might want to set the initial capacity to 0 (more on that later) but didn’t want the pool to shrink to 0.  In WLS 10.3.6, we added minimum capacity to specify the lower limit to which a pool will shrink.  If minimum capacity is not set, it defaults to the initial capacity for upward compatibility.   We also did some work on the shrinking in release 10.3.4 to reduce thrashing; the algorithm that used to shrink to the maximum of the currently used connections or the initial capacity (basically the unused connections were all released) was changed to shrink by half of the unused connections. The simple approach to sizing the pool is to set the initial/minimum capacity to the maximum capacity.  Doing this creates all connections at startup, avoiding creating connections on demand and the pool is stable.  However, there are a number of reasons not to take this simple approach. When WLS is booted, the deployment of the data source includes synchronously creating the connections.  The more connections that are configured in initial capacity, the longer the boot time for WLS (there have been several projects for parallel boot in WLS but none that are available).  Related to creating a lot of connections at boot time is the problem of logon storms (the database gets too much work at one time).   WLS has a solution for that by setting the login delay seconds on the pool but that also increases the boot time. There are a number of cases where it is desirable to set the initial capacity to 0.  By doing that, the overhead of creating connections is deferred out of the boot and the database doesn’t need to be available.  An application may not want WLS to automatically connect to the database until it is actually needed, such as for some code/warm failover configurations. There are a number of cases where minimum capacity should be less than maximum capacity.  Connections are generally expensive to keep around.  They cause state to be kept on both the client and the server, and the state on the backend may be heavy (for example, a process).  Depending on the vendor, connection usage may cost money.  If work load is not constant, then database connections can be freed up by shrinking the pool when connections are not in use.  When using Active GridLink, connections can be created as needed according to runtime load balancing (RLB) percentages instead of by connection load balancing (CLB) during data source deployment. Shrinking is an effective technique for clearing the pool when connections are not in use.  In addition to the obvious reason that there times where the workload is lighter,  there are some configurations where the database and/or firewall conspire to make long-unused or too-old connections no longer viable.  There are also some data source features where the connection has state and cannot be used again unless the state matches the request.  Examples of this are identity based pooling where the connection has a particular owner and XA affinity where the connection is associated with a particular RAC node.  At this point, WLS does not re-purpose (discard/replace) connections and shrinking is a way to get rid of the unused existing connection and get a new one with the correct state when needed. So far, the discussion has focused on the relationship of initial, minimum, and maximum capacity.  Computing the maximum size requires some knowledge about the application and the current number of simultaneously active users, web sessions, batch programs, or whatever access patterns are common.  The applications should be written to only reserve and close connections as needed but multiple statements, if needed, should be done in one reservation (don’t get/close more often than necessary).  This means that the size of the pool is likely to be significantly smaller then the number of users.   If possible, you can pick a size and see how it performs under simulated or real load.  There is a high-water mark statistic (ActiveConnectionsHighCount) that tracks the maximum connections concurrently used.  In general, you want the size to be big enough so that you never run out of connections but no bigger.   It will need to deal with spikes in usage, which is where shrinking after the spike is important.  Of course, the database capacity also has a big influence on the decision since it’s important not to overload the database machine.  Planning also needs to happen if you are running in a Multi-Data Source or Active GridLink configuration and expect that the remaining nodes will take over the connections when one of the nodes in the cluster goes down.  For XA affinity, additional headroom is also recommended.  In summary, setting initial and maximum capacity to be the same may be simple but there are many other factors that may be important in making the decision about sizing.

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• SQL SERVER – Securing TRUNCATE Permissions in SQL Server

  - by pinaldave

  Download the Script of this article from here. On December 11, 2010, Vinod Kumar, a Databases & BI technology evangelist from Microsoft Corporation, graced Ahmedabad by spending some time with the Community during the Community Tech Days (CTD) event. As he was running through a few demos, Vinod asked the audience one of the most fundamental and common interview questions – “What is the difference between a DELETE and TRUNCATE?“ Ahmedabad SQL Server User Group Expert Nakul Vachhrajani has come up with excellent solutions of the same. I must congratulate Nakul for this excellent solution and as a encouragement to User Group member, I am publishing the same article over here. Nakul Vachhrajani is a Software Specialist and systems development professional with Patni Computer Systems Limited. He has functional experience spanning legacy code deprecation, system design, documentation, development, implementation, testing, maintenance and support of complex systems, providing business intelligence solutions, database administration, performance tuning, optimization, product management, release engineering, process definition and implementation. He has comprehensive grasp on Database Administration, Development and Implementation with MS SQL Server and C, C++, Visual C++/C#. He has about 6 years of total experience in information technology. Nakul is an member of the Ahmedabad and Gandhinagar SQL Server User Groups, and actively contributes to the community by actively participating in multiple forums and websites like SQLAuthority.com, BeyondRelational.com, SQLServerCentral.com and many others. Please note: The opinions expressed herein are Nakul own personal opinions and do not represent his employer’s view in anyway. All data from everywhere here on Earth go through a series of  four distinct operations, identified by the words: CREATE, READ, UPDATE and DELETE, or simply, CRUD. Putting in Microsoft SQL Server terms, is the process goes like this: INSERT, SELECT, UPDATE and DELETE/TRUNCATE. Quite a few interesting responses were received and evaluated live during the session. To summarize them, the most important similarity that came out was that both DELETE and TRUNCATE participate in transactions. The major differences (not all) that came out of the exercise were: DELETE: DELETE supports a WHERE clause DELETE removes rows from a table, row-by-row Because DELETE moves row-by-row, it acquires a row-level lock Depending upon the recovery model of the database, DELETE is a fully-logged operation. Because DELETE moves row-by-row, it can fire off triggers TRUNCATE: TRUNCATE does not support a WHERE clause TRUNCATE works by directly removing the individual data pages of a table TRUNCATE directly occupies a table-level lock. (Because a lock is acquired, and because TRUNCATE can also participate in a transaction, it has to be a logged operation) TRUNCATE is, therefore, a minimally-logged operation; again, this depends upon the recovery model of the database Triggers are not fired when TRUNCATE is used (because individual row deletions are not logged) Finally, Vinod popped the big homework question that must be critically analyzed: “We know that we can restrict a DELETE operation to a particular user, but how can we restrict the TRUNCATE operation to a particular user?” After returning home and having a nice cup of coffee, I noticed that my gray cells immediately started to work. Below was the result of my research. As what is always said, the devil is in the details. Upon looking at the Permissions section for the TRUNCATE statement in Books On Line, the following jumps right out: “The minimum permission required is ALTER on table_name. TRUNCATE TABLE permissions default to the table owner, members of the sysadmin fixed server role, and the db_owner and db_ddladmin fixed database roles, and are not transferable. However, you can incorporate the TRUNCATE TABLE statement within a module, such as a stored procedure, and grant appropriate permissions to the module using the EXECUTE AS clause.“ Now, what does this mean? Unlike DELETE, one cannot directly assign permissions to a user/set of users allowing or revoking TRUNCATE rights. However, there is a way to circumvent this. It is important to recall that in Microsoft SQL Server, database engine security surrounds the concept of a “securable”, which is any object like a table, stored procedure, trigger, etc. Rights are assigned to a principal on a securable. Refer to the image below (taken from the SQL Server Books On Line). urable”, which is any object like a table, stored procedure, trigger, etc. Rights are assigned to a principal on a securable. Refer to the image below (taken from the SQL Server Books On Line). SETTING UP THE ENVIRONMENT – (01A_Truncate Table Permissions.sql) Script Provided at the end of the article. By the end of this demo, one will be able to do all the CRUD operations, except the TRUNCATE, and the other will only be able to execute the TRUNCATE. All you will need for this test is any edition of SQL Server 2008. (With minor changes, these scripts can be made to work with SQL 2005.) We begin by creating the following: 1.       A test database 2.        Two database roles: associated logins and users 3.       Switch over to the test database and create a test table. Then, add some data into it. I am using row constructors, which is new to SQL 2008. Creating the modules that will be used to enforce permissions 1.       We have already created one of the modules that we will be assigning permissions to. That module is the table: TruncatePermissionsTest 2.       We will now create two stored procedures; one is for the DELETE operation and the other for the TRUNCATE operation. Please note that for all practical purposes, the end result is the same – all data from the table TruncatePermissionsTest is removed Assigning the permissions Now comes the most important part of the demonstration – assigning permissions. A permissions matrix can be worked out as under: To apply the security rights, we use the GRANT and DENY clauses, as under: That’s it! We are now ready for our big test! THE TEST (01B_Truncate Table Test Queries.sql) Script Provided at the end of the article. I will now need two separate SSMS connections, one with the login AllowedTruncate and the other with the login RestrictedTruncate. Running the test is simple; all that’s required is to run through the script – 01B_Truncate Table Test Queries.sql. What I will demonstrate here via screen-shots is the behavior of SQL Server when logged in as the AllowedTruncate user. There are a few other combinations than what are highlighted here. I will leave the reader the right to explore the behavior of the RestrictedTruncate user and these additional scenarios, as a form of self-study. 1.       Testing SELECT permissions 2.       Testing TRUNCATE permissions (Remember, “deny by default”?) 3.       Trying to circumvent security by trying to TRUNCATE the table using the stored procedure Hence, we have now proved that a user can indeed be assigned permissions to specifically assign TRUNCATE permissions. I also hope that the above has sparked curiosity towards putting some security around the probably “destructive” operations of DELETE and TRUNCATE. I would like to wish each and every one of the readers a very happy and secure time with Microsoft SQL Server. (Please find the scripts – 01A_Truncate Table Permissions.sql and 01B_Truncate Table Test Queries.sql that have been used in this demonstration. Please note that these scripts contain purely test-level code only. These scripts must not, at any cost, be used in the reader’s production environments). 01A_Truncate Table Permissions.sql /* ***************************************************************************************************************** Developed By          : Nakul Vachhrajani Functionality         : This demo is focused on how to allow only TRUNCATE permissions to a particular user How to Use            : 1. Run through, step-by-step through the sequence till Step 08 to create a test database 2. Switch over to the "Truncate Table Test Queries.sql" and execute it step-by-step in two different SSMS windows, one where you have logged in as 'RestrictedTruncate', and the other as 'AllowedTruncate' 3. Come back to "Truncate Table Permissions.sql" 4. Execute Step 10 to cleanup! Modifications         : December 13, 2010 - NAV - Updated to add a security matrix and improve code readability when applying security December 12, 2010 - NAV - Created ***************************************************************************************************************** */ -- Step 01: Create a new test database CREATE DATABASE TruncateTestDB GO USE TruncateTestDB GO -- Step 02: Add roles and users to demonstrate the security of the Truncate operation -- 2a. Create the new roles CREATE ROLE AllowedTruncateRole; GO CREATE ROLE RestrictedTruncateRole; GO -- 2b. Create new logins CREATE LOGIN AllowedTruncate WITH PASSWORD = 'truncate@2010', CHECK_POLICY = ON GO CREATE LOGIN RestrictedTruncate WITH PASSWORD = 'truncate@2010', CHECK_POLICY = ON GO -- 2c. Create new Users using the roles and logins created aboave CREATE USER TruncateUser FOR LOGIN AllowedTruncate WITH DEFAULT_SCHEMA = dbo GO CREATE USER NoTruncateUser FOR LOGIN RestrictedTruncate WITH DEFAULT_SCHEMA = dbo GO -- 2d. Add the newly created login to the newly created role sp_addrolemember 'AllowedTruncateRole','TruncateUser' GO sp_addrolemember 'RestrictedTruncateRole','NoTruncateUser' GO -- Step 03: Change over to the test database USE TruncateTestDB GO -- Step 04: Create a test table within the test databse CREATE TABLE TruncatePermissionsTest (Id INT IDENTITY(1,1), Name NVARCHAR(50)) GO -- Step 05: Populate the required data INSERT INTO TruncatePermissionsTest VALUES (N'Delhi'), (N'Mumbai'), (N'Ahmedabad') GO -- Step 06: Encapsulate the DELETE within another module CREATE PROCEDURE proc_DeleteMyTable WITH EXECUTE AS SELF AS DELETE FROM TruncateTestDB..TruncatePermissionsTest GO -- Step 07: Encapsulate the TRUNCATE within another module CREATE PROCEDURE proc_TruncateMyTable WITH EXECUTE AS SELF AS TRUNCATE TABLE TruncateTestDB..TruncatePermissionsTest GO -- Step 08: Apply Security /* *****************************SECURITY MATRIX*************************************** =================================================================================== Object                   | Permissions |                 Login |             | AllowedTruncate   |   RestrictedTruncate |             |User:NoTruncateUser|   User:TruncateUser =================================================================================== TruncatePermissionsTest  | SELECT,     |      GRANT        |      (Default) | INSERT,     |                   | | UPDATE,     |                   | | DELETE      |                   | -------------------------+-------------+-------------------+----------------------- TruncatePermissionsTest  | ALTER       |      DENY         |      (Default) -------------------------+-------------+----*/----------------+----------------------- proc_DeleteMyTable | EXECUTE | GRANT | DENY -------------------------+-------------+-------------------+----------------------- proc_TruncateMyTable | EXECUTE | DENY | GRANT -------------------------+-------------+-------------------+----------------------- *****************************SECURITY MATRIX*************************************** */ /* Table: TruncatePermissionsTest*/ GRANT SELECT, INSERT, UPDATE, DELETE ON TruncateTestDB..TruncatePermissionsTest TO NoTruncateUser GO DENY ALTER ON TruncateTestDB..TruncatePermissionsTest TO NoTruncateUser GO /* Procedure: proc_DeleteMyTable*/ GRANT EXECUTE ON TruncateTestDB..proc_DeleteMyTable TO NoTruncateUser GO DENY EXECUTE ON TruncateTestDB..proc_DeleteMyTable TO TruncateUser GO /* Procedure: proc_TruncateMyTable*/ DENY EXECUTE ON TruncateTestDB..proc_TruncateMyTable TO NoTruncateUser GO GRANT EXECUTE ON TruncateTestDB..proc_TruncateMyTable TO TruncateUser GO -- Step 09: Test --Switch over to the "Truncate Table Test Queries.sql" and execute it step-by-step in two different SSMS windows: --    1. one where you have logged in as 'RestrictedTruncate', and --    2. the other as 'AllowedTruncate' -- Step 10: Cleanup sp_droprolemember 'AllowedTruncateRole','TruncateUser' GO sp_droprolemember 'RestrictedTruncateRole','NoTruncateUser' GO DROP USER TruncateUser GO DROP USER NoTruncateUser GO DROP LOGIN AllowedTruncate GO DROP LOGIN RestrictedTruncate GO DROP ROLE AllowedTruncateRole GO DROP ROLE RestrictedTruncateRole GO USE MASTER GO DROP DATABASE TruncateTestDB GO 01B_Truncate Table Test Queries.sql /* ***************************************************************************************************************** Developed By          : Nakul Vachhrajani Functionality         : This demo is focused on how to allow only TRUNCATE permissions to a particular user How to Use            : 1. Switch over to this from "Truncate Table Permissions.sql", Step #09 2. Execute this step-by-step in two different SSMS windows a. One where you have logged in as 'RestrictedTruncate', and b. The other as 'AllowedTruncate' 3. Return back to "Truncate Table Permissions.sql" 4. Execute Step 10 to cleanup! Modifications         : December 12, 2010 - NAV - Created ***************************************************************************************************************** */ -- Step 09A: Switch to the test database USE TruncateTestDB GO -- Step 09B: Ensure that we have valid data SELECT * FROM TruncatePermissionsTest GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Line 1 -- The SELECT permission was denied on the object 'TruncatePermissionsTest', database 'TruncateTestDB', schema 'dbo'. --Step 09C: Attempt to Truncate Data from the table without using the stored procedure TRUNCATE TABLE TruncatePermissionsTest GO -- (Expected: Following error will occur) --  Msg 1088, Level 16, State 7, Line 2 --  Cannot find the object "TruncatePermissionsTest" because it does not exist or you do not have permissions. -- Step 09D:Regenerate Test Data INSERT INTO TruncatePermissionsTest VALUES (N'London'), (N'Paris'), (N'Berlin') GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Line 1 -- The INSERT permission was denied on the object 'TruncatePermissionsTest', database 'TruncateTestDB', schema 'dbo'. --Step 09E: Attempt to Truncate Data from the table using the stored procedure EXEC proc_TruncateMyTable GO -- (Expected: Will execute successfully with 'AllowedTruncate' user, will error out as under with 'RestrictedTruncate') -- Msg 229, Level 14, State 5, Procedure proc_TruncateMyTable, Line 1 -- The EXECUTE permission was denied on the object 'proc_TruncateMyTable', database 'TruncateTestDB', schema 'dbo'. -- Step 09F:Regenerate Test Data INSERT INTO TruncatePermissionsTest VALUES (N'Madrid'), (N'Rome'), (N'Athens') GO --Step 09G: Attempt to Delete Data from the table without using the stored procedure DELETE FROM TruncatePermissionsTest GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Line 2 -- The DELETE permission was denied on the object 'TruncatePermissionsTest', database 'TruncateTestDB', schema 'dbo'. -- Step 09H:Regenerate Test Data INSERT INTO TruncatePermissionsTest VALUES (N'Spain'), (N'Italy'), (N'Greece') GO --Step 09I: Attempt to Delete Data from the table using the stored procedure EXEC proc_DeleteMyTable GO -- (Expected: Following error will occur if logged in as "AllowedTruncate") -- Msg 229, Level 14, State 5, Procedure proc_DeleteMyTable, Line 1 -- The EXECUTE permission was denied on the object 'proc_DeleteMyTable', database 'TruncateTestDB', schema 'dbo'. --Step 09J: Close this SSMS window and return back to "Truncate Table Permissions.sql" Thank you Nakul to take up the challenge and prove that Ahmedabad and Gandhinagar SQL Server User Group has talent to solve difficult problems. Reference: Pinal Dave (http://blog.SQLAuthority.com) Filed under: Best Practices, Pinal Dave, Readers Contribution, Readers Question, SQL, SQL Authority, SQL Query, SQL Scripts, SQL Security, SQL Server, SQL Tips and Tricks, T SQL, Technology

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• How to avoid the Portlet Skin mismatch

  - by Martin Deh

  here are probably many on going debates whether to use portlets or taskflows in a WebCenter custom portal application.  Usually the main battle on which side to take in these debates are centered around which technology enables better performance.  The good news is that both of my colleagues, Maiko Rocha and George Maggessy have posted their respective views on this topic so I will not have to further the discussion.  However, if you do plan to use portlets in a WebCenter custom portal application, this post will help you not have the "portlet skin mismatch" issue.   An example of the presence of the mismatch can be view from the applications log: The skin customsharedskin.desktop specified on the requestMap will be used even though the consumer's skin's styleSheetDocumentId on the requestMap does not match the local skin's styleSheetDocument's id. This will impact performance since the consumer and producer stylesheets cannot be shared. The producer styleclasses will not be compressed to avoid conflicts. A reason the ids do not match may be the jars are not identical on the producer and the consumer. For example, one might have trinidad-skins.xml's skin-additions in a jar file on the class path that the other does not have. Notice that due to the mismatch the portlet's CSS will not be able to be compressed, which will most like impact performance in the portlet's consuming portal. The first part of the blog will define the portlet mismatch and cover some debugging tips that can help you solve the portlet mismatch issue.  Following that I will give a complete example of the creating, using and sharing a shared skin in both a portlet producer and the consumer application. Portlet Mismatch Defined  In general, when you consume/render an ADF page (or task flow) using the ADF Portlet bridge, the portlet (producer) would try to use the skin of the consumer page - this is called skin-sharing. When the producer cannot match the consumer skin, the portlet would generate its own stylesheet and reference it from its markup - this is called mismatched-skin. This can happen because: The consumer and producer use different versions of ADF Faces, or The consumer has additional skin-additions that the producer doesn't have or vice-versa, or The producer does not have the consumer skin For case (1) & (2) above, the producer still uses the consumer skin ID to render its markup. For case (3), the producer would default to using portlet skin. If there is a skin mis-match then there may be a performance hit because: The browser needs to fetch this extra stylesheet (though it should be cached unless expires caching is turned off) The generated portlet markup uses uncompressed styles resulting in a larger markup It is often not obvious when a skin mismatch occurs, unless you look for either of these indicators: The log messages in the producer log, for example: The skin blafplus-rich.desktop specified on the requestMap will not be used because the styleSheetDocument id on the requestMap does not match the local skin's styleSheetDocument's id. It could mean the jars are not identical. For example, one might have trinidad-skins.xml's skin-additions in a jar file on the class path that the other does not have. View the portlet markup inside the iframe, there should be a <link> tag to the portlet stylesheet resource like this (note the CSS is proxied through consumer's resourceproxy): <link rel=\"stylesheet\" charset=\"UTF-8\" type=\"text/css\" href=\"http:.../resourceproxy/portletId...252525252Fadf%252525252Fstyles%252525252Fcache%252525252Fblafplus-rich-portlet-d1062g-en-ltr-gecko.css... Using HTTP monitoring tool (eg, firebug, httpwatch), you can see a request is made to the portlet stylesheet resource (see URL above) There are a number of reasons for mismatched-skin. For skin to match the producer and consumer must match the following configurations: The ADF Faces version (different versions may have different style selectors) Style Compression, this is defined in the web.xml (default value is false, i.e. compression is ON) Tonal styles or themes, also defined in the web.xml via context-params The same skin additions (jars with skin) are available for both producer and consumer.  Skin additions are defined in the trinidad-skins.xml, using the <skin-addition> tags. These are then aggregated from all the jar files in the classpath. If there's any jar that exists on the producer but not the consumer, or vice veras, you get a mismatch. Debugging Tips  Ensure the style compression and tonal styles/themes match on the consumer and producer, by looking at the web.xml documents for the consumer & producer applications It is bit more involved to determine if the jars match.  However, you can enable the Trinidad logging to show which skin-addition it is processing.  To enable this feature, update the logging.xml log level of both the producer and consumer WLS to FINEST.  For example, in the case of the WebLogic server used by JDeveloper: $JDEV_USER_DIR/system<version number>/DefaultDomain/config/fmwconfig/servers/DefaultServer/logging.xml Add a new entry: <logger name="org.apache.myfaces.trinidadinternal.skin.SkinUtils" level="FINEST"/> Restart WebLogic.  Run the consumer page, you should see the following logging in both the consumer and producer log files. Any entries that don't match is the cause of the mismatch.  The following is an example of what the log will produce with this setting: [SRC_CLASS: org.apache.myfaces.trinidadinternal.skin.SkinUtils] [APP: WebCenter] [SRC_METHOD: _getMetaInfSkinsNodeList] Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/announcement-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/calendar-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/custComps-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/forum-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/page-service-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/peopleconnections-kudos-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/peopleconnections-wall-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/portlet-client-adf-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/rtc-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/serviceframework-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/smarttag-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.skin/in1ar8/APP-INF/lib/spaces-service-skins.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/oracle.webcenter.composer/3yo7j/WEB-INF/lib/custComps-skin.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/adf.oracle.domain.webapp/q433f9/WEB-INF/lib/adf-richclient-impl-11.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/adf.oracle.domain.webapp/q433f9/WEB-INF/lib/dvt-faces.jar!/META-INF/trinidad-skins.xml Processing skin URL:zip:/tmp/_WL_user/adf.oracle.domain.webapp/q433f9/WEB-INF/lib/dvt-trinidad.jar!/META-INF/trinidad-skins.xml   The Complete Example The first step is to create the shared library.  The WebCenter documentation covering this is located here in section 15.7.  In addition, our ADF guru Frank Nimphius also covers this in hes blog.  Here are my steps (in JDeveloper) to create the skin that will be used as the shared library for both the portlet producer and consumer. Create a new Generic Application Give application name (i.e. MySharedSkin) Give a project name (i.e. MySkinProject) Leave Project Technologies blank (none selected), and click Finish Create the trinidad-skins.xml Right-click on the MySkinProject node in the Application Navigator and select "New" In the New Galley, click on "General", select "File" from the Items, and click OK In the Create File dialog, name the file trinidad-skins.xml, and (IMPORTANT) give the directory path to MySkinProject\src\META-INF In the trinidad-skins.xml, complete the skin entry.  for example: <?xml version="1.0" encoding="windows-1252" ?> <skins xmlns="http://myfaces.apache.org/trinidad/skin">   <skin>     <id>mysharedskin.desktop</id>     <family>mysharedskin</family>     <extends>fusionFx-v1.desktop</extends>     <style-sheet-name>css/mysharedskin.css</style-sheet-name>   </skin> </skins> Create CSS file In the Application Navigator, right click on the META-INF folder (where the trinidad-skins.xml is located), and select "New" In the New Gallery, select Web-Tier-> HTML, CSS File from the the Items and click OK In the Create Cascading Style Sheet dialog, give the name (i.e. mysharedskin.css) Ensure that the Directory path is the under the META-INF (i.e. MySkinProject\src\META-INF\css) Once the new CSS opens in the editor, add in a style selector.  For example, this selector will style the background of a particular panelGroupLayout: af|panelGroupLayout.customPGL{     background-color:Fuchsia; } Create the MANIFEST.MF (used for deployment JAR) In the Application Navigator, right click on the META-INF folder (where the trinidad-skins.xml is located), and select "New" In the New Galley, click on "General", select "File" from the Items, and click OK In the Create File dialog, name the file MANIFEST.MF, and (IMPORTANT) ensure that the directory path is to MySkinProject\src\META-INF Complete the MANIFEST.MF, where the extension name is the shared library name Manifest-Version: 1.1 Created-By: Martin Deh Implementation-Title: mysharedskin Extension-Name: mysharedskin.lib.def Specification-Version: 1.0.1 Implementation-Version: 1.0.1 Implementation-Vendor: MartinDeh Create new Deployment Profile Right click on the MySkinProject node, and select New From the New Gallery, select General->Deployment Profiles, Shared Library JAR File from Items, and click OK In the Create Deployment Profile dialog, give name (i.e.mysharedskinlib) and click OK In the Edit JAR Deployment dialog, un-check Include Manifest File option  Select Project Output->Contributors, and check Project Source Path Select Project Output->Filters, ensure that all items under the META-INF folder are selected Click OK to exit the Project Properties dialog Deploy the shared lib to WebLogic (start server before steps) Right click on MySkin Project and select Deploy For this example, I will deploy to JDeverloper WLS In the Deploy dialog, select Deploy to Weblogic Application Server and click Next Choose IntegratedWebLogicServer and click Next Select Deploy to selected instances in the domain radio, select Default Server (note: server must be already started), and ensure Deploy as a shared Library radio is selected Click Finish Open the WebLogic console to see the deployed shared library The following are the steps to create a simple test Portlet Create a new WebCenter Portal - Portlet Producer Application In the Create Portlet Producer dialog, select default settings and click Finish Right click on the Portlets node and select New IIn the New Gallery, select Web-Tier->Portlets, Standards-based Java Portlet (JSR 286) and click OK In the General Portlet information dialog, give portlet name (i.e. MyPortlet) and click Next 2 times, stopping at Step 3 In the Content Types, select the "view" node, in the Implementation Method, select the Generate ADF-Faces JSPX radio and click Finish Once the portlet code is generated, open the view.jspx in the source editor Based on the simple CSS entry, which sets the background color of a panelGroupLayout, replace the <af:form/> tag with the example code <af:form>         <af:panelGroupLayout id="pgl1" styleClass="customPGL">           <af:outputText value="background from shared lib skin" id="ot1"/>         </af:panelGroupLayout>  </af:form> Since this portlet is to use the shared library skin, in the generated trinidad-config.xml, remove both the skin-family tag and the skin-version tag In the Application Resources view, under Descriptors->META-INF, double-click to open the weblogic-application.xml Add a library reference to the shared skin library (note: the library-name must match the extension-name declared in the MANIFEST.MF):  <library-ref>     <library-name>mysharedskin.lib.def</library-name>  </library-ref> Notice that a reference to oracle.webcenter.skin exists.  This is important if this portlet is going to be consumed by a WebCenter Portal application.  If this tag is not present, the portlet skin mismatch will happen.  Configure the portlet for deployment Create Portlet deployment WAR Right click on the Portlets node and select New In the New Gallery, select Deployment Profiles, WAR file from Items and click OK In the Create Deployment Profile dialog, give name (i.e. myportletwar), click OK Keep all of the defaults, however, remember the Context Root entry (i.e. MyPortlet4SharedLib-Portlets-context-root, this will be needed to obtain the producer WSDL URL) Click OK, then OK again to exit from the Properties dialog Since the weblogic-application.xml has to be included in the deployment, the portlet must be deployed as a WAR, within an EAR In the Application dropdown, select Deploy->New Deployment Profile... By default EAR File has been selected, click OK Give Deployment Profile (EAR) a name (i.e. MyPortletProducer) and click OK In the Properties dialog, select Application Assembly and ensure that the myportletwar is checked Keep all of the other defaults and click OK For this demo, un-check the Auto Generate ..., and all of the Security Deployment Options, click OK Save All In the Application dropdown, select Deploy->MyPortletProducer In the Deployment Action, select Deploy to Application Server, click Next Choose IntegratedWebLogicServer and click Next Select Deploy to selected instances in the domain radio, select Default Server (note: server must be already started), and ensure Deploy as a standalone Application radio is selected The select deployment type (identifying the deployment as a JSR 286 portlet) dialog appears.  Keep default radio "Yes" selection and click OK Open the WebLogic console to see the deployed Portlet The last step is to create the test portlet consuming application.  This will be done using the OOTB WebCenter Portal - Framework Application.  Create the Portlet Producer Connection In the JDeveloper Deployment log, copy the URL of the portlet deployment (i.e. http://localhost:7101/MyPortlet4SharedLib-Portlets-context-root Open a browser and paste in the URL.  The Portlet information page should appear.  Click on the WSRP v2 WSDL link Copy the URL from the browser (i.e. http://localhost:7101/MyPortlet4SharedLib-Portlets-context-root/portlets/wsrp2?WSDL) In the Application Resources view, right click on the Connections folder and select New Connection->WSRP Connection Give the producer a name or accept the default, click Next Enter (paste in) the WSDL URL, click Next If connection to Portlet is succesful, Step 3 (Specify Additional ...) should appear.  Accept defaults and click Finish Add the portlet to a test page Open the home.jspx.  Note in the visual editor, the orange dashed border, which identifies the panelCustomizable tag. From the Application Resources. select the MyPortlet portlet node, and drag and drop the node into the panelCustomizable section.  A Confirm Portlet Type dialog appears, keep default ADF Rich Portlet and click OK Configure the portlet to use the shared skin library Open the weblogic-application.xml and add the library-ref entry (mysharedskin.lib.def) for the shared skin library.  See create portlet example above for the steps Since by default, the custom portal using a managed bean to (dynamically) determine the skin family, the default trinidad-config.xml will need to be altered Open the trinidad-config.xml in the editor and replace the EL (preferenceBean) for the skin-family tag, with mysharedskin (this is the skin-family named defined in the trinidad-skins.xml) Remove the skin-version tag Right click on the index.html to test the application   Notice that the JDeveloper log view does not have any reporting of a skin mismatch.  In addition, since I have configured the extra logging outlined in debugging section above, I can see the processed skin jar in both the producer and consumer logs: <SkinUtils> <_getMetaInfSkinsNodeList> Processing skin URL:zip:/JDeveloper/system11.1.1.6.38.61.92/DefaultDomain/servers/DefaultServer/upload/mysharedskin.lib.def/[email protected]/app/mysharedskinlib.jar!/META-INF/trinidad-skins.xml 

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• jQuery, ASP.NET, and Browser History

  - by Stephen Walther

  One objection that people always raise against Ajax applications concerns browser history. Because an Ajax application updates its content by performing sneaky Ajax postbacks, the browser backwards and forwards buttons don’t work as you would normally expect. In a normal, non-Ajax application, when you click the browser back button, you return to a previous state of the application. For example, if you are paging through a set of movie records, you might return to the previous page of records. In an Ajax application, on the other hand, the browser backwards and forwards buttons do not work as you would expect. If you navigate to the second page in a list of records and click the backwards button, you won’t return to the previous page. Most likely, you will end up navigating away from the application entirely (which is very unexpected and irritating). Bookmarking presents a similar problem. You cannot bookmark a particular page of records in an Ajax application because the address bar does not reflect the state of the application. The Ajax Solution There is a solution to both of these problems. To solve both of these problems, you must take matters into your own hands and take responsibility for saving and restoring your application state yourself. Furthermore, you must ensure that the address bar gets updated to reflect the state of your application. In this blog entry, I demonstrate how you can take advantage of a jQuery library named bbq that enables you to control browser history (and make your Ajax application bookmarkable) in a cross-browser compatible way. The JavaScript Libraries In this blog entry, I take advantage of the following four JavaScript files: jQuery-1.4.2.js – The jQuery library. Available from the Microsoft Ajax CDN at http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js jquery.pager.js – Used to generate pager for navigating records. Available from http://plugins.jquery.com/project/Pager microtemplates.js – John Resig’s micro-templating library. Available from http://ejohn.org/blog/javascript-micro-templating/ jquery.ba-bbq.js – The Back Button and Query (BBQ) Library. Available from http://benalman.com/projects/jquery-bbq-plugin/ All of these libraries, with the exception of the Micro-templating library, are available under the MIT open-source license. The Ajax Application Let’s start by building a simple Ajax application that enables you to page through a set of movie database records, 3 records at a time. We’ll use my favorite database named MoviesDB. This database contains a Movies table that looks like this: We’ll create a data model for this database by taking advantage of the ADO.NET Entity Framework. The data model looks like this: Finally, we’ll expose the data to the universe with the help of a WCF Data Service named MovieService.svc. The code for the data service is contained in Listing 1. Listing 1 – MovieService.svc using System.Data.Services; using System.Data.Services.Common; namespace WebApplication1 { public class MovieService : DataService<MoviesDBEntities> { public static void InitializeService(DataServiceConfiguration config) { config.SetEntitySetAccessRule("Movies", EntitySetRights.AllRead); config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; } } } The WCF Data Service in Listing 1 exposes the movies so that you can query the movie database table with URLs that looks like this: http://localhost:2474/MovieService.svc/Movies -- Returns all movies http://localhost:2474/MovieService.svc/Movies?$top=5 – Returns 5 movies The HTML page in Listing 2 enables you to page through the set of movies retrieved from the WCF Data Service. Listing 2 – Original.html <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Movies with History</title> <link href="Design/Pager.css" rel="stylesheet" type="text/css" /> </head> <body> <h1>Page <span id="pageNumber"></span> of <span id="pageCount"></span></h1> <div id="pager"></div> <br style="clear:both" /><br /> <div id="moviesContainer"></div> <script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script> <script src="App_Scripts/Microtemplates.js" type="text/javascript"></script> <script src="App_Scripts/jquery.pager.js" type="text/javascript"></script> <script type="text/javascript"> var pageSize = 3, pageIndex = 0; // Show initial page of movies showMovies(); function showMovies() { // Build OData query var query = "/MovieService.svc" // base URL + "/Movies" // top-level resource + "?$skip=" + pageIndex * pageSize // skip records + "&$top=" + pageSize // take records + " &$inlinecount=allpages"; // include total count of movies // Make call to WCF Data Service $.ajax({ dataType: "json", url: query, success: showMoviesComplete }); } function showMoviesComplete(result) { // unwrap results var movies = result["d"]["results"]; var movieCount = result["d"]["__count"] // Show movies using template var showMovie = tmpl("<li><%=Id%> - <%=Title %></li>"); var html = ""; for (var i = 0; i < movies.length; i++) { html += showMovie(movies[i]); } $("#moviesContainer").html(html); // show pager $("#pager").pager({ pagenumber: (pageIndex + 1), pagecount: Math.ceil(movieCount / pageSize), buttonClickCallback: selectPage }); // Update page number and page count $("#pageNumber").text(pageIndex + 1); $("#pageCount").text(movieCount); } function selectPage(pageNumber) { pageIndex = pageNumber - 1; showMovies(); } </script> </body> </html> The page in Listing 3 has the following three functions: showMovies() – Performs an Ajax call against the WCF Data Service to retrieve a page of movies. showMoviesComplete() – When the Ajax call completes successfully, this function displays the movies by using a template. This function also renders the pager user interface. selectPage() – When you select a particular page by clicking on a page number in the pager UI, this function updates the current page index and calls the showMovies() function. Figure 1 illustrates what the page looks like when it is opened in a browser. Figure 1 If you click the page numbers then the browser history is not updated. Clicking the browser forward and backwards buttons won’t move you back and forth in browser history. Furthermore, the address displayed in the address bar does not change when you navigate to different pages. You cannot bookmark any page except for the first page. Adding Browser History The Back Button and Query (bbq) library enables you to add support for browser history and bookmarking to a jQuery application. The bbq library supports two important methods: jQuery.bbq.pushState(object) – Adds state to browser history. jQuery.bbq.getState(key) – Gets state from browser history. The bbq library also supports one important event: hashchange – This event is raised when the part of an address after the hash # is changed. The page in Listing 3 demonstrates how to use the bbq library to add support for browser navigation and bookmarking to an Ajax page. Listing 3 – Default.html <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Movies with History</title> <link href="Design/Pager.css" rel="stylesheet" type="text/css" /> </head> <body> <h1>Page <span id="pageNumber"></span> of <span id="pageCount"></span></h1> <div id="pager"></div> <br style="clear:both" /><br /> <div id="moviesContainer"></div> <script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.4.2.js" type="text/javascript"></script> <script src="App_Scripts/jquery.ba-bbq.js" type="text/javascript"></script> <script src="App_Scripts/Microtemplates.js" type="text/javascript"></script> <script src="App_Scripts/jquery.pager.js" type="text/javascript"></script> <script type="text/javascript"> var pageSize = 3, pageIndex = 0; $(window).bind('hashchange', function (e) { pageIndex = e.getState("pageIndex") || 0; pageIndex = parseInt(pageIndex); showMovies(); }); $(window).trigger('hashchange'); function showMovies() { // Build OData query var query = "/MovieService.svc" // base URL + "/Movies" // top-level resource + "?$skip=" + pageIndex * pageSize // skip records + "&$top=" + pageSize // take records +" &$inlinecount=allpages"; // include total count of movies // Make call to WCF Data Service $.ajax({ dataType: "json", url: query, success: showMoviesComplete }); } function showMoviesComplete(result) { // unwrap results var movies = result["d"]["results"]; var movieCount = result["d"]["__count"] // Show movies using template var showMovie = tmpl("<li><%=Id%> - <%=Title %></li>"); var html = ""; for (var i = 0; i < movies.length; i++) { html += showMovie(movies[i]); } $("#moviesContainer").html(html); // show pager $("#pager").pager({ pagenumber: (pageIndex + 1), pagecount: Math.ceil(movieCount / pageSize), buttonClickCallback: selectPage }); // Update page number and page count $("#pageNumber").text(pageIndex + 1); $("#pageCount").text(movieCount); } function selectPage(pageNumber) { pageIndex = pageNumber - 1; $.bbq.pushState({ pageIndex: pageIndex }); } </script> </body> </html> Notice the first chunk of JavaScript code in Listing 3: $(window).bind('hashchange', function (e) { pageIndex = e.getState("pageIndex") || 0; pageIndex = parseInt(pageIndex); showMovies(); }); $(window).trigger('hashchange'); When the hashchange event occurs, the current pageIndex is retrieved by calling the e.getState() method. The value is returned as a string and the value is cast to an integer by calling the JavaScript parseInt() function. Next, the showMovies() method is called to display the page of movies. The $(window).trigger() method is called to raise the hashchange event so that the initial page of records will be displayed. When you click a page number, the selectPage() method is invoked. This method adds the current page index to the address by calling the following method: $.bbq.pushState({ pageIndex: pageIndex }); For example, if you click on page number 2 then page index 1 is saved to the URL. The URL looks like this: Notice that when you click on page 2 then the browser address is updated to look like: /Default.htm#pageIndex=1 If you click on page 3 then the browser address is updated to look like: /Default.htm#pageIndex=2 Because the browser address is updated when you navigate to a new page number, the browser backwards and forwards button will work to navigate you backwards and forwards through the page numbers. When you click page 2, and click the backwards button, you will navigate back to page 1. Furthermore, you can bookmark a particular page of records. For example, if you bookmark the URL /Default.htm#pageIndex=1 then you will get the second page of records whenever you open the bookmark. Summary You should not avoid building Ajax applications because of worries concerning browser history or bookmarks. By taking advantage of a JavaScript library such as the bbq library, you can make your Ajax applications behave in exactly the same way as a normal web application.

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• MVVM in Task-It

  As I'm gearing up to write a post about dynamic XAP loading with MEF, I'd like to first talk a bit about MVVM, the Model-View-ViewModel pattern, as I will be leveraging this pattern in my future posts. Download Source Code Why MVVM? Your first question may be, "why do I need this pattern? I've been using a code-behind approach for years and it works fine." Well, you really don't have to make the switch to MVVM, but let me first explain some of the benefits I see for doing so. MVVM Benefits Testability - This is the one you'll probably hear the most about when it comes to MVVM. Moving most of the code from your code-behind to a separate view model class means you can now write unit tests against the view model without any knowledge of a view (UserControl). Multiple UIs - Let's just say that you've created a killer app, it's running in the browser, and maybe you've even made it run out-of-browser. Now what if your boss comes to you and says, "I heard about this new Windows Phone 7 device that is coming out later this year. Can you start porting the app to that device?". Well, now you have to create a new UI (UserControls, etc.) because you have a lot less screen real estate to work with. So what do you do, copy all of your existing UserControls, paste them, rename them, and then start changing the code? Hmm, that doesn't sound so good. But wait, if most of the code that makes your browser-based app tick lives in view model classes, now you can create new view (UserControls) for Windows Phone 7 that reference the same view model classes as your browser-based app. Page state - In Silverlight you're at some point going to be faced with the same issue you dealt with for years in ASP.NET, maintaining page state. Let's say a user hits your Products page, does some stuff (filters record, etc.), then leaves the page and comes back later. It would be best if the Products page was in the same state as when they left it right? Well, if you've thrown away your view (UserControl or Page) and moved off to another part of the UI, when you come back to Products you're probably going to re-instantiate your view...which will put it right back in the state it was when it started. Hmm, not good. Well, with a little help from MEF you can store the state in your view model class, MEF will keep that view model instance hanging around in memory, and then you simply rebind your view to the view model class. I made that sound easy, but it's actually a bit of work to properly store and restore the state. At least it can be done though, which will make your users a lot happier! I'll talk more about this in an upcoming blog post. No event handlers? Another nice thing about MVVM is that you can bind your UserControls to the view model, which may eliminate the need for event handlers in your code-behind. So instead of having a Click handler on a Button (or RadMenuItem), for example, you can now bind your control's Command property to a DelegateCommand in your view model (I'll talk more about Commands in an upcoming post). Instead of having a SelectionChanged event handler on your RadGridView you can now bind its SelectedItem property to a property in your view model, and each time the user clicks a row, the view model property's setter will be called. Now through the magic of binding we can eliminate the need for traditional code-behind based event handlers on our user interface controls, and the best thing is that the view model knows about everything that's going on...which means we can test things without a user interface. The brains of the operation So what we're seeing here is that the view is now just a dumb layer that binds to the view model, and that the view model is in control of just about everything, like what happens when a RadGridView row is selected, or when a RadComboBoxItem is selected, or when a RadMenuItem is clicked. It is also responsible for loading data when the page is hit, as well as kicking off data inserts, updates and deletions. Once again, all of this stuff can be tested without the need for a user interface. If the test works, then it'll work regardless of whether the user is hitting the browser-based version of your app, or the Windows Phone 7 version. Nice! The database Before running the code for this app you will need to create the database. First, create a database called MVVMProject in SQL Server, then run MVVMProject.sql in the MVVMProject/Database directory of your downloaded .zip file. This should give you a Task table with 3 records in it. When you fire up the solution you will also need to update the connection string in web.config to point to your database instead of IBM12\SQLSERVER2008. The code One note about this code is that it runs against the latest Silverlight 4 RC and WCF RIA Services code. Please see my first blog post about updating to the RC bits. Beta to RC - Part 1 At the top of this post is a link to a sample project that demonstrates a sample application with a Tasks page that uses the MVVM pattern. This is a simplified version of how I have implemented the Tasks page in the Task-It application. Youll notice that Tasks.xaml has very little code to it. Just a TextBlock that displays the page title and a ContentControl. <StackPanel>     <TextBlock Text="Tasks" Style="{StaticResource PageTitleStyle}"/>     <Rectangle Style="{StaticResource StandardSpacerStyle}"/>     <ContentControl x:Name="ContentControl1"/> </StackPanel> In List.xaml we have a RadGridView. Notice that the ItemsSource is bound to a property in the view model class call Tasks, SelectedItem is bound to a property in the view model called SelectedItem, and IsBusy is bound to a property in the view model called IsLoading. <Grid>     <telerikGridView:RadGridView ItemsSource="{Binding Tasks}" SelectedItem="{Binding SelectedItem, Mode=TwoWay}"                                  IsBusy="{Binding IsLoading}" AutoGenerateColumns="False" IsReadOnly="True" RowIndicatorVisibility="Collapsed"                IsFilteringAllowed="False" ShowGroupPanel="False">         <telerikGridView:RadGridView.Columns>             <telerikGridView:GridViewDataColumn Header="Name" DataMemberBinding="{Binding Name}" Width="3*"/>             <telerikGridView:GridViewDataColumn Header="Due" DataMemberBinding="{Binding DueDate}" DataFormatString="{}{0:d}" Width="*"/>         </telerikGridView:RadGridView.Columns>     </telerikGridView:RadGridView> </Grid> In Details.xaml we have a Save button that is bound to a property called SaveCommand in our view model. We also have a simple form (Im using a couple of controls here from Silverlight.FX for the form layout, FormPanel and Label simply because they make for a clean XAML layout). Notice that the FormPanel is also bound to the SelectedItem in the view model (the same one that the RadGridView is). The two form controls, the TextBox and RadDatePicker) are bound to the SelectedItem's Name and DueDate properties. These are properties of the Task object that WCF RIA Services creates. <StackPanel>     <Button Content="Save" Command="{Binding SaveCommand}" HorizontalAlignment="Left"/>     <Rectangle Style="{StaticResource StandardSpacerStyle}"/>     <fxui:FormPanel DataContext="{Binding SelectedItem}" Style="{StaticResource FormContainerStyle}">         <fxui:Label Text="Name:"/>         <TextBox Text="{Binding Name, Mode=TwoWay}"/>         <fxui:Label Text="Due:"/>         <telerikInput:RadDatePicker SelectedDate="{Binding DueDate, Mode=TwoWay}"/>     </fxui:FormPanel> </StackPanel> In the code-behind of the Tasks control, Tasks.xaml.cs, I created an instance of the view model class (TasksViewModel) in the constructor and set it as the DataContext for the control. The Tasks page will load one of two child UserControls depending on whether you are viewing the list of tasks (List.xaml) or the form for editing a task (Details.xaml). // Set the DataContext to an instance of the view model class var viewModel = new TasksViewModel(); DataContext = viewModel;   // Child user controls (inherit DataContext from this user control) List = new List(); // RadGridView Details = new Details(); // Form When the page first loads, the List is loaded into the ContentControl. // Show the RadGridView first ContentControl1.Content = List; In the code-behind we also listen for a couple of the view models events. The ItemSelected event will be fired when the user clicks on a record in the RadGridView in the List control. The SaveCompleted event will be fired when the user clicks Save in the Details control (the form). Here the view model is in control, and is letting the view know when something needs to change. // Listeners for the view model's events viewModel.ItemSelected += OnItemSelected; viewModel.SaveCompleted += OnSaveCompleted; The event handlers toggle the view between the RadGridView (List) and the form (Details). void OnItemSelected(object sender, RoutedEventArgs e) {     // Show the form     ContentControl1.Content = Details; }   void OnSaveCompleted(object sender, RoutedEventArgs e) {     // Show the RadGridView     ContentControl1.Content = List; } In TasksViewModel, we instantiate a DataContext object and a SaveCommand in the constructor. DataContext is a WCF RIA Services object that well use to retrieve the list of Tasks and to save any changes to a task. Ill talk more about this and Commands in future post, but for now think of the SaveCommand as an event handler that is called when the Save button in the form is clicked. DataContext = new DataContext(); SaveCommand = new DelegateCommand(OnSave); When the TasksViewModel constructor is called we also make a call to LoadTasks. This sets IsLoading to true (which causes the RadGridViews busy indicator to appear) and retrieves the records via WCF RIA Services.         public LoadOperation<Task> LoadTasks()         {             // Show the loading message             IsLoading = true;             // Get the data via WCF RIA Services. When the call has returned, called OnTasksLoaded.             return DataContext.Load(DataContext.GetTasksQuery(), OnTasksLoaded, false);         } When the data is returned, OnTasksLoaded is called. This sets IsLoading to false (which hides the RadGridViews busy indicator), and fires property changed notifications to the UI to let it know that the IsLoading and Tasks properties have changed. This property changed notification basically tells the UI to rebind. void OnTasksLoaded(LoadOperation<Task> lo) {     // Hide the loading message     IsLoading = false;       // Notify the UI that Tasks and IsLoading properties have changed     this.OnPropertyChanged(p => p.Tasks);     this.OnPropertyChanged(p => p.IsLoading); } Next lets look at the view models SelectedItem property. This is the one thats bound to both the RadGridView and the form. When the user clicks a record in the RadGridView its setter gets called (set a breakpoint and see what I mean). The other code in the setter lets the UI know that the SelectedItem has changed (so the form displays the correct data), and fires the event that notifies the UI that a selection has occurred (which tells the UI to switch from List to Details). public Task SelectedItem {     get { return _selectedItem; }     set     {         _selectedItem = value;           // Let the UI know that the SelectedItem has changed (forces it to re-bind)         this.OnPropertyChanged(p => p.SelectedItem);         // Notify the UI, so it can switch to the Details (form) page         NotifyItemSelected();     } } One last thing, saving the data. When the Save button in the form is clicked it fires the SaveCommand, which calls the OnSave method in the view model (once again, set a breakpoint to see it in action). public void OnSave() {     // Save the changes via WCF RIA Services. When the save is complete, call OnSaveCompleted.     DataContext.SubmitChanges(OnSaveCompleted, null); } In OnSave, we tell WCF RIA Services to submit any changes, which there will be if you changed either the Name or the Due Date in the form. When the save is completed, it calls OnSaveCompleted. This method fires a notification back to the UI that the save is completed, which causes the RadGridView (List) to show again. public virtual void OnSaveCompleted(SubmitOperation so) {     // Clear the item that is selected in the grid (in case we want to select it again)     SelectedItem = null;     // Notify the UI, so it can switch back to the List (RadGridView) page     NotifySaveCompleted(); } Did you know that DotNetSlackers also publishes .net articles written by top known .net Authors? We already have over 80 articles in several categories including Silverlight. Take a look: here.

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• Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

  - by Stephen.Walther

  The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", “readwrite”); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", "readwrite"); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", "readwrite"); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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• Metro Walkthrough: Creating a Task List with a ListView and IndexedDB

  - by Stephen.Walther

  The goal of this blog entry is to describe how you can work with data in a Metro style application written with JavaScript. In particular, we create a super simple Task List application which enables you to create and delete tasks. Here’s a video which demonstrates how the Task List application works: In order to build this application, I had to take advantage of several features of the WinJS library and technologies including: IndexedDB – The Task List application stores data in an IndexedDB database. HTML5 Form Validation – The Task List application uses HTML5 validation to ensure that a required field has a value. ListView Control – The Task List application displays the tasks retrieved from the IndexedDB database in a WinJS ListView control. Creating the IndexedDB Database The Task List application stores all of its data in an IndexedDB database named TasksDB. This database is opened/created with the following code: var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; The msIndexedDB.open() method accepts two parameters: the name of the database to open and the version of the database to open. If a database with a matching version already exists, then calling the msIndexedDB.open() method opens a connection to the existing database. If the database does not exist then the upgradeneeded event is raised. You handle the upgradeneeded event to create a new database. In the code above, the upgradeneeded event handler creates an object store named “tasks” (An object store roughly corresponds to a database table). When you add items to the tasks object store then each item gets an id property with an auto-incremented value automatically. The code above also includes an error event handler. If the IndexedDB database cannot be opened or created, for whatever reason, then an error message is written to the Visual Studio JavaScript Console window. Displaying a List of Tasks The TaskList application retrieves its list of tasks from the tasks object store, which we created above, and displays the list of tasks in a ListView control. Here is how the ListView control is declared: <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> The ListView control is bound to the TaskList.tasks.dataSource data source. The TaskList.tasks.dataSource is created with the following code: // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks }); Notice the success event handler. This handler is called when a database is successfully opened/created. In the code above, all of the items from the tasks object store are retrieved into a cursor and added to a WinJS.Binding.List object named tasks. Because the ListView control is bound to the WinJS.Binding.List object, copying the tasks from the object store into the WinJS.Binding.List object causes the tasks to appear in the ListView: Adding a New Task You add a new task in the Task List application by entering the title of a new task into an HTML form and clicking the Add button. Here’s the markup for creating the form: <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> Notice that the INPUT element includes a required attribute. In a Metro application, you can take advantage of HTML5 Validation to validate form fields. If you don’t enter a value for the newTaskTitle field then the following validation error message is displayed: For a brief introduction to HTML5 validation, see my previous blog entry: http://stephenwalther.com/blog/archive/2012/03/13/html5-form-validation.aspx When you click the Add button, the form is submitted and the form submit event is raised. The following code is executed in the default.js file: // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); The code above retrieves the title of the new task and calls the addTask() method in the tasks.js file. Here’s the code for the addTask() method which is responsible for actually adding the new task to the IndexedDB database: // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } The code above does two things. First, it adds the new task to the tasks object store in the IndexedDB database. Second, it adds the new task to the data source bound to the ListView. The dataSource.insertAtEnd() method is called to add the new task to the data source so the new task will appear in the ListView (with a nice little animation). Deleting Existing Tasks The Task List application enables you to select one or more tasks by clicking or tapping on one or more tasks in the ListView. When you click the Delete button, the selected tasks are removed from both the IndexedDB database and the ListView. For example, in the following screenshot, two tasks are selected. The selected tasks appear with a teal background and a checkmark: When you click the Delete button, the following code in the default.js file is executed: // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); The selected tasks are retrieved with the TaskList selection.getItem() method. In the code above, the deleteTask() method is called for each of the selected tasks. Here’s the code for the deleteTask() method: // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } This code does two things: it deletes the existing task from the database and removes the existing task from the ListView. In both cases, the right task is removed by using the key associated with the task. However, the task key is different in the case of the database and in the case of the ListView. In the case of the database, the task key is the value of the task id property. In the case of the ListView, on the other hand, the task key is auto-generated by the ListView. When the task is removed from the ListView, an animation is used to collapse the tasks which appear above and below the task which was removed. The Complete Code Above, I did a lot of jumping around between different files in the application and I left out sections of code. For the sake of completeness, I want to include the entire code here: the default.html, default.js, and tasks.js files. Here are the contents of the default.html file. This file contains the UI for the Task List application: <!DOCTYPE html> <html> <head> <meta charset="utf-8"> <title>Task List</title> <!-- WinJS references --> <link href="//Microsoft.WinJS.0.6/css/ui-dark.css" rel="stylesheet"> <script src="//Microsoft.WinJS.0.6/js/base.js"></script> <script src="//Microsoft.WinJS.0.6/js/ui.js"></script> <!-- TaskList references --> <link href="/css/default.css" rel="stylesheet"> <script src="/js/default.js"></script> <script type="text/javascript" src="js/tasks.js"></script> <style type="text/css"> body { font-size: x-large; } form { display: inline; } #appContainer { margin: 20px; width: 600px; } .win-container { padding: 10px; } </style> </head> <body> <div> <!-- Templates --> <div id="taskTemplate" data-win-control="WinJS.Binding.Template"> <div> <span data-win-bind="innerText:title"></span> </div> </div> <h1>Super Task List</h1> <div id="appContainer"> <form id="addTaskForm"> <input id="newTaskTitle" title="New Task" required /> <button>Add</button> </form> <button id="btnDeleteTasks">Delete</button> <div id="tasksListView" data-win-control="WinJS.UI.ListView" data-win-options="{ itemDataSource: TaskList.tasks.dataSource, itemTemplate: select('#taskTemplate'), tapBehavior: 'toggleSelect', selectionMode: 'multi', layout: { type: WinJS.UI.ListLayout } }"> </div> </div> </div> </body> </html> Here is the code for the default.js file. This code wires up the Add Task form and Delete button: (function () { "use strict"; var app = WinJS.Application; app.onactivated = function (eventObject) { if (eventObject.detail.kind === Windows.ApplicationModel.Activation.ActivationKind.launch) { WinJS.UI.processAll().then(function () { // Get reference to Tasks ListView var tasksListView = document.getElementById("tasksListView"); // Handle Add Task document.getElementById("addTaskForm").addEventListener("submit", function (evt) { evt.preventDefault(); var newTaskTitle = document.getElementById("newTaskTitle"); TaskList.addTask({ title: newTaskTitle.value }); newTaskTitle.value = ""; }); // Handle Delete Tasks document.getElementById("btnDeleteTasks").addEventListener("click", function (evt) { tasksListView.winControl.selection.getItems().then(function(items) { items.forEach(function (item) { TaskList.deleteTask(item); }); }); }); }); } }; app.start(); })(); Finally, here is the tasks.js file. This file contains all of the code for opening, creating, and interacting with IndexedDB: (function () { "use strict"; // Create the data source var tasks = new WinJS.Binding.List(); // Open the database var db; var req = window.msIndexedDB.open("TasksDB", 1); req.onerror = function () { console.log("Could not open database"); }; req.onupgradeneeded = function (evt) { var newDB = evt.target.result; newDB.createObjectStore("tasks", { keyPath: "id", autoIncrement:true }); }; // Load the data source with data from the database req.onsuccess = function () { db = req.result; var tran = db.transaction("tasks"); tran.objectStore("tasks").openCursor().onsuccess = function(event) { var cursor = event.target.result; tasks.dataSource.beginEdits(); if (cursor) { tasks.dataSource.insertAtEnd(null, cursor.value); cursor.continue(); } else { tasks.dataSource.endEdits(); }; }; }; // Add a new task function addTask(taskToAdd) { var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var addRequest = transaction.objectStore("tasks").add(taskToAdd); addRequest.onsuccess = function (evt) { taskToAdd.id = evt.target.result; tasks.dataSource.insertAtEnd(null, taskToAdd); } } // Delete an existing task function deleteTask(listViewItem) { // Database key != ListView key var dbKey = listViewItem.data.id; var listViewKey = listViewItem.key; // Remove item from db and, if success, remove item from ListView var transaction = db.transaction("tasks", IDBTransaction.READ_WRITE); var deleteRequest = transaction.objectStore("tasks").delete(dbKey); deleteRequest.onsuccess = function () { tasks.dataSource.remove(listViewKey); } } // Expose the data source and functions WinJS.Namespace.define("TaskList", { tasks: tasks, addTask: addTask, deleteTask: deleteTask }); })(); Summary I wrote this blog entry because I wanted to create a walkthrough of building a simple database-driven application. In particular, I wanted to demonstrate how you can use a ListView control with an IndexedDB database to store and retrieve database data.

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• CodePlex Daily Summary for Friday, April 06, 2012

  CodePlex Daily Summary for Friday, April 06, 2012Popular ReleasesBetter Explorer: Better Explorer 2.0.0.861 Alpha: - fixed new folder button operation not work well in some situations - removed some unnecessary code like subclassing that is not needed anymore - Added option to make Better Exlorer default (at least for WIN+E operations) - Added option to enable file operation replacements (like Terracopy) to work with Better Explorer - Added some basic usability to "Share" button - Other fixesLightFarsiDictionary - ??????? ??? ?????/???????: LightFarsiDictionary - v1: LightFarsiDictionary - v1WPF Application Framework (WAF): WPF Application Framework (WAF) 2.5.0.3: Version: 2.5.0.3 (Milestone 3): This release contains the source code of the WPF Application Framework (WAF) and the sample applications. Requirements .NET Framework 4.0 (The package contains a solution file for Visual Studio 2010) The unit test projects require Visual Studio 2010 Professional Changelog Legend: [B] Breaking change; [O] Marked member as obsolete [O] WAF: Mark the StringBuilderExtensions class as obsolete because the AppendInNewLine method can be replaced with string.Jo...Community TFS Build Extensions: April 2012: Release notes to follow...ClosedXML - The easy way to OpenXML: ClosedXML 0.65.2: Aside from many bug fixes we now have Conditional Formatting The conditional formatting was sponsored by http://www.bewing.nl (big thanks) New on v0.65.1 Fixed issue when loading conditional formatting with default values for icon sets New on v0.65.2 Fixed issue loading conditional formatting Improved inserts performanceLiberty: v3.2.0.0 Release 4th April 2012: Change Log-Added -Halo 3 support (invincibility, ammo editing) -Halo 3: ODST support (invincibility, ammo editing) -The file transfer page now shows its progress in the Windows 7 taskbar -"About this build" settings page -Reach Change what an object is carrying -Reach Change which node a carried object is attached to -Reach Object node viewer and exporter -Reach Change which weapons you are carrying from the object editor -Reach Edit the weapon controller of vehicles and turrets -An error dia...MSBuild Extension Pack: April 2012: Release Blog Post The MSBuild Extension Pack April 2012 release provides a collection of over 435 MSBuild tasks. A high level summary of what the tasks currently cover includes the following: System Items: Active Directory, Certificates, COM+, Console, Date and Time, Drives, Environment Variables, Event Logs, Files and Folders, FTP, GAC, Network, Performance Counters, Registry, Services, Sound Code: Assemblies, AsyncExec, CAB Files, Code Signing, DynamicExecute, File Detokenisation, GUID’...DotNetNuke® Community Edition CMS: 06.01.05: Major Highlights Fixed issue that stopped users from creating vocabularies when the portal ID was not zero Fixed issue that caused modules configured to be displayed on all pages to be added to the wrong container in new pages Fixed page quota restriction issue in the Ribbon Bar Removed restriction that would not allow users to use a dash in page names. Now users can create pages with names like "site-map" Fixed issue that was causing the wrong container to be loaded in modules wh...51Degrees.mobi - Mobile Device Detection and Redirection: 2.1.3.1: One Click Install from NuGet Changes to Version 2.1.3.11. [assembly: AllowPartiallyTrustedCallers] has been added back into the AssemblyInfo.cs file to prevent failures with other assemblies in Medium trust environments. 2. The Lite data embedded into the assembly has been updated to include devices from December 2011. The 42 new RingMark properties will return Unknown if RingMark data is not available. Changes to Version 2.1.2.11Code Changes 1. The project is now licenced under the Mozilla...MVC Controls Toolkit: Mvc Controls Toolkit 2.0.0: Added Support for Mvc4 beta and WebApi The SafeqQuery and HttpSafeQuery IQueryable implementations that works as wrappers aroung any IQueryable to protect it from unwished queries. "Client Side" pager specialized in paging javascript data coming either from a remote data source, or from local data. LinQ like fluent javascript api to build queries either against remote data sources, or against local javascript data, with exactly the same interface. There are 3 different query objects exp...ExtAspNet: ExtAspNet v3.1.2: ExtAspNet - ?? ExtJS ??? ASP.NET 2.0 ???，????? AJAX ?????????? ExtAspNet ????? ExtJS ??? ASP.NET 2.0 ???，????? AJAX ??????????。 ExtAspNet ??????? JavaScript，?? CSS，?? UpdatePanel，?? ViewState，?? WebServices ???????。 ??????: IE 7.0, Firefox 3.6, Chrome 3.0, Opera 10.5, Safari 3.0+ ????：Apache License 2.0 (Apache) ??：http://extasp.net/ ??：http://bbs.extasp.net/ ??：http://extaspnet.codeplex.com/ ??：http://sanshi.cnblogs.com/ ????： +2012-04-04 v3.1.2 -??IE?????????????BUG（??"about:blank"?...nopCommerce. Open source shopping cart (ASP.NET MVC): nopcommerce 2.50: Highlight features & improvements: • Significant performance optimization. • Allow store owners to create several shipments per order. Added a new shipping status: “Partially shipped”. • Pre-order support added. Enables your customers to place a Pre-Order and pay for the item in advance. Displays “Pre-order” button instead of “Buy Now” on the appropriate pages. Makes it possible for customer to buy available goods and Pre-Order items during one session. It can be managed on a product variant ...WiX Toolset: WiX v3.6 RC0: WiX v3.6 RC0 (3.6.2803.0) provides support for VS11 and a more stable Burn engine. For more information see Rob's blog post about the release: http://robmensching.com/blog/posts/2012/4/3/WiX-v3.6-Release-Candidate-Zero-availableSageFrame: SageFrame 2.0: Sageframe is an open source ASP.NET web development framework developed using ASP.NET 3.5 with service pack 1 (sp1) technology. It is designed specifically to help developers build dynamic website by providing core functionality common to most web applications.iTuner - The iTunes Companion: iTuner 1.5.4475: Fix to parse empty playlists in iTunes LibraryDocument.Editor: 2012.2: Whats New for Document.Editor 2012.2: New Save Copy support New Page Setup support Minor Bug Fix's, improvements and speed upsDotNet.Highcharts: DotNet.Highcharts 1.2 with Examples: Tested and adapted to the latest version of Highcharts 2.2.1 Fixed Issue 359: Not implemented serialization array of type: System.Drawing.Color[] Fixed Issue 364: Crosshairs defined as array of CrosshairsForamt generates bad Highchart code For the example project: Added newest version of Highcharts 2.2.1 Added new demos to How To's section: Bind Data From Dictionary Bind Data From Object List Custom Theme Tooltip Crosshairs Theming The Reset Button Plot Band EventsVidCoder: 1.3.2: Added option for the minimum title length to scan. Added support to enable or disable LibDVDNav. Added option to prompt to delete source files after clearing successful completed items. Added option to disable remembering recent files and folders. Tweaked number box to only select all on a quick click.MJP's DirectX 11 Samples: Light Indexed Deferred Rendering: Implements light indexed deferred using per-tile light lists calculated in a compute shader, as well as a traditional deferred renderer that uses a compute shader for per-tile light culling and per-pixel shading.Pcap.Net: Pcap.Net 0.9.0 (66492): Pcap.Net - March 2012 Release Pcap.Net is a .NET wrapper for WinPcap written in C++/CLI and C#. It Features almost all WinPcap features and includes a packet interpretation framework. Version 0.9.0 (Change Set 66492)March 31, 2012 release of the Pcap.Net framework. Follow Pcap.Net on Google+Follow Pcap.Net on Google+ Files Pcap.Net.DevelopersPack.0.9.0.66492.zip - Includes all the tutorial example projects source files, the binaries in a 3rdParty directory and the documentation. It include...New Projects.Net Mutation Testing Tool: This tool will help for making and unit testing mutation changes. Mutation tests improve unit tests and applications.African Honey Bee Application Suite: This is the home of the software behind the African Honey Bee community enrichment project.Create Schema: Object extension method that generates schema creation scripts in SQL (MS SQL SERVER) from c# classes to rapidly get database tables from an existing class structure. Just edit the scripts (they are just guesses of how the database should look) to make them fit your database needs and then run them as a query in SQL Server. Check out vecklare.blogspot.se for more examples. CrtTfsDemo: demo project to test code review tool integration with tfsDolphins Salaam: This Library is a Cross Platform, UDP Broadcast solution for Peer to Peer network client detection. It is written in pure C# and is Mono and .Net compatible. It has been tested on Mac OS X, Windows, Linux, iOS, Android, Xbox and it is expected to be compatible with every other Mono compatible platform. The library is ready to use out of box and there is almost zero configurations needed for it to start working, regarding that, it is also flexible and configurable for your needs.Enhanced Content Query Webpart: This Enhanced Content Query Webpart for SharePoint 2010 is meant for the advanced application developer. You will be able to create any rollup of pages of any Content Type(s), Site Column(s) from any subsite(s) with (any) style you want. Xslt skills are required.fangxue: huijiaFrameworkComponent: frameworkcomponent 4 companyFsXna3DGame: 3D game written in XNA and F# (still very much a work in progress)GeoLock: GeoLock is a proof of concept (PoC). GeoLock demonstrates how to retrieve geolocation data from surrounding Wi-Fi networks triangulation without Global Positioning System (GPS) hardware. grab-libs: A quick hack to bundle up the shared libraries needed to run an i386 executable on an x86_64 machine.Logical Game Of Life: Make Logic Component with a game of life algoritmMagic Box: Magic Box is the application for "hiding" files in NTFS file system. NTFS Alternate Data Streams are used for this.Notes: Application to create fast notes on your Windows Phone.Orchard Google Infographics: **NOTE: Only works with Orchard >= v1.4** This module leverages Google's Infographics api for generating QR codes for each content item that uses the Orchard.Autoroute part. The api documentation may be found at https://developers.google.com/chart/infographics/docs/qr_codesOutlook Calendar Cleaner: If you port your email from a Lotus Notes server to Exchange Server or to Office 365, your Mac Outlook calendar items may be missing. This includes calendar appointments and meeting requests. This may include items that were ported over and also new items created after the port.Polarity: Polarity is a plugin-oriented bot written in C# for deviantArt chat written with simplicity and ease of use for plugin developers as the number one goal.Pool Game Paradise: Pool Game Club of Augmentum Inc. Wuhan Site.RCT2 DatChecker: A utility for Rollercoaster Tycoon 2 that catalogs, displays, and helps manage object files (*.DAT). Examine objects frame by frame or copy object images to the clipboard. Sort objects by size, type, or content. Use DatChecker to find and remove unwanted or duplicate objects, or RecipeML Manager: This project creates C# classes that support the RecipeML standard. It also enhances that standard to support full daily and weekly menus.s0t0o0c0k3246352543: 345234324324324324ScoutGames: scout games portalSharePoint All Page Scripting: This solution is the skeleton of the JavaScript loading in all pages on the SharePoint site collection. This solution can be deployed as a "sandbox solution". Supports the Office365 of course. ??????????SharePoint ?????????????????????????Java?????????????。 ????????????????????????。 ???、????Office365?????????。testtom04052012git02: testtom04052012git02testtom04052012tfs01: testtom04052012tfs01testtom04052012tfs03: testtom04052012tfs03Visual Studio Pattern Automation Toolkit (VSPAT): VSPAT is a set of development and deployment tools from Microsoft that generate and execute Visual Studio extensions called 'Pattern Toolkits' that redeliver best practices, expertise and proven solutions faster, more reliably and more consistently. If you are an *IT professional* are you are looking to build and deploy custom solutions that include proven best practices to improve quality, consistency and time to market. And if you wish to spend significantly less time having to learn all...Wet: Wet, the game.WPF Data Editors: WPF Data Editor controls contains most of editor controls in WPF.xSolon Instructions: Framework to run scripts

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• Inside the Concurrent Collections: ConcurrentDictionary

  - by Simon Cooper

  Using locks to implement a thread-safe collection is rather like using a sledgehammer - unsubtle, easy to understand, and tends to make any other tool redundant. Unlike the previous two collections I looked at, ConcurrentStack and ConcurrentQueue, ConcurrentDictionary uses locks quite heavily. However, it is careful to wield locks only where necessary to ensure that concurrency is maximised. This will, by necessity, be a higher-level look than my other posts in this series, as there is quite a lot of code and logic in ConcurrentDictionary. Therefore, I do recommend that you have ConcurrentDictionary open in a decompiler to have a look at all the details that I skip over. The problem with locks There's several things to bear in mind when using locks, as encapsulated by the lock keyword in C# and the System.Threading.Monitor class in .NET (if you're unsure as to what lock does in C#, I briefly covered it in my first post in the series): Locks block threads The most obvious problem is that threads waiting on a lock can't do any work at all. No preparatory work, no 'optimistic' work like in ConcurrentQueue and ConcurrentStack, nothing. It sits there, waiting to be unblocked. This is bad if you're trying to maximise concurrency. Locks are slow Whereas most of the methods on the Interlocked class can be compiled down to a single CPU instruction, ensuring atomicity at the hardware level, taking out a lock requires some heavy lifting by the CLR and the operating system. There's quite a bit of work required to take out a lock, block other threads, and wake them up again. If locks are used heavily, this impacts performance. Deadlocks When using locks there's always the possibility of a deadlock - two threads, each holding a lock, each trying to aquire the other's lock. Fortunately, this can be avoided with careful programming and structured lock-taking, as we'll see. So, it's important to minimise where locks are used to maximise the concurrency and performance of the collection. Implementation As you might expect, ConcurrentDictionary is similar in basic implementation to the non-concurrent Dictionary, which I studied in a previous post. I'll be using some concepts introduced there, so I recommend you have a quick read of it. So, if you were implementing a thread-safe dictionary, what would you do? The naive implementation is to simply have a single lock around all methods accessing the dictionary. This would work, but doesn't allow much concurrency. Fortunately, the bucketing used by Dictionary allows a simple but effective improvement to this - one lock per bucket. This allows different threads modifying different buckets to do so in parallel. Any thread making changes to the contents of a bucket takes the lock for that bucket, ensuring those changes are thread-safe. The method that maps each bucket to a lock is the GetBucketAndLockNo method: private void GetBucketAndLockNo( int hashcode, out int bucketNo, out int lockNo, int bucketCount) { // the bucket number is the hashcode (without the initial sign bit) // modulo the number of buckets bucketNo = (hashcode & 0x7fffffff) % bucketCount; // and the lock number is the bucket number modulo the number of locks lockNo = bucketNo % m_locks.Length; } However, this does require some changes to how the buckets are implemented. The 'implicit' linked list within a single backing array used by the non-concurrent Dictionary adds a dependency between separate buckets, as every bucket uses the same backing array. Instead, ConcurrentDictionary uses a strict linked list on each bucket: This ensures that each bucket is entirely separate from all other buckets; adding or removing an item from a bucket is independent to any changes to other buckets. Modifying the dictionary All the operations on the dictionary follow the same basic pattern: void AlterBucket(TKey key, ...) { int bucketNo, lockNo; 1: GetBucketAndLockNo( key.GetHashCode(), out bucketNo, out lockNo, m_buckets.Length); 2: lock (m_locks[lockNo]) { 3: Node headNode = m_buckets[bucketNo]; 4: Mutate the node linked list as appropriate } } For example, when adding another entry to the dictionary, you would iterate through the linked list to check whether the key exists already, and add the new entry as the head node. When removing items, you would find the entry to remove (if it exists), and remove the node from the linked list. Adding, updating, and removing items all follow this pattern. Performance issues There is a problem we have to address at this point. If the number of buckets in the dictionary is fixed in the constructor, then the performance will degrade from O(1) to O(n) when a large number of items are added to the dictionary. As more and more items get added to the linked lists in each bucket, the lookup operations will spend most of their time traversing a linear linked list. To fix this, the buckets array has to be resized once the number of items in each bucket has gone over a certain limit. (In ConcurrentDictionary this limit is when the size of the largest bucket is greater than the number of buckets for each lock. This check is done at the end of the TryAddInternal method.) Resizing the bucket array and re-hashing everything affects every bucket in the collection. Therefore, this operation needs to take out every lock in the collection. Taking out mutiple locks at once inevitably summons the spectre of the deadlock; two threads each hold a lock, and each trying to acquire the other lock. How can we eliminate this? Simple - ensure that threads never try to 'swap' locks in this fashion. When taking out multiple locks, always take them out in the same order, and always take out all the locks you need before starting to release them. In ConcurrentDictionary, this is controlled by the AcquireLocks, AcquireAllLocks and ReleaseLocks methods. Locks are always taken out and released in the order they are in the m_locks array, and locks are all released right at the end of the method in a finally block. At this point, it's worth pointing out that the locks array is never re-assigned, even when the buckets array is increased in size. The number of locks is fixed in the constructor by the concurrencyLevel parameter. This simplifies programming the locks; you don't have to check if the locks array has changed or been re-assigned before taking out a lock object. And you can be sure that when a thread takes out a lock, another thread isn't going to re-assign the lock array. This would create a new series of lock objects, thus allowing another thread to ignore the existing locks (and any threads controlling them), breaking thread-safety. Consequences of growing the array Just because we're using locks doesn't mean that race conditions aren't a problem. We can see this by looking at the GrowTable method. The operation of this method can be boiled down to: private void GrowTable(Node[] buckets) { try { 1: Acquire first lock in the locks array // this causes any other thread trying to take out // all the locks to block because the first lock in the array // is always the one taken out first // check if another thread has already resized the buckets array // while we were waiting to acquire the first lock 2: if (buckets != m_buckets) return; 3: Calculate the new size of the backing array 4: Node[] array = new array[size]; 5: Acquire all the remaining locks 6: Re-hash the contents of the existing buckets into array 7: m_buckets = array; } finally { 8: Release all locks } } As you can see, there's already a check for a race condition at step 2, for the case when the GrowTable method is called twice in quick succession on two separate threads. One will successfully resize the buckets array (blocking the second in the meantime), when the second thread is unblocked it'll see that the array has already been resized & exit without doing anything. There is another case we need to consider; looking back at the AlterBucket method above, consider the following situation: Thread 1 calls AlterBucket; step 1 is executed to get the bucket and lock numbers. Thread 2 calls GrowTable and executes steps 1-5; thread 1 is blocked when it tries to take out the lock in step 2. Thread 2 re-hashes everything, re-assigns the buckets array, and releases all the locks (steps 6-8). Thread 1 is unblocked and continues executing, but the calculated bucket and lock numbers are no longer valid. Between calculating the correct bucket and lock number and taking out the lock, another thread has changed where everything is. Not exactly thread-safe. Well, a similar problem was solved in ConcurrentStack and ConcurrentQueue by storing a local copy of the state, doing the necessary calculations, then checking if that state is still valid. We can use a similar idea here: void AlterBucket(TKey key, ...) { while (true) { Node[] buckets = m_buckets; int bucketNo, lockNo; GetBucketAndLockNo( key.GetHashCode(), out bucketNo, out lockNo, buckets.Length); lock (m_locks[lockNo]) { // if the state has changed, go back to the start if (buckets != m_buckets) continue; Node headNode = m_buckets[bucketNo]; Mutate the node linked list as appropriate } break; } } TryGetValue and GetEnumerator And so, finally, we get onto TryGetValue and GetEnumerator. I've left these to the end because, well, they don't actually use any locks. How can this be? Whenever you change a bucket, you need to take out the corresponding lock, yes? Indeed you do. However, it is important to note that TryGetValue and GetEnumerator don't actually change anything. Just as immutable objects are, by definition, thread-safe, read-only operations don't need to take out a lock because they don't change anything. All lockless methods can happily iterate through the buckets and linked lists without worrying about locking anything. However, this does put restrictions on how the other methods operate. Because there could be another thread in the middle of reading the dictionary at any time (even if a lock is taken out), the dictionary has to be in a valid state at all times. Every change to state has to be made visible to other threads in a single atomic operation (all relevant variables are marked volatile to help with this). This restriction ensures that whatever the reading threads are doing, they never read the dictionary in an invalid state (eg items that should be in the collection temporarily removed from the linked list, or reading a node that has had it's key & value removed before the node itself has been removed from the linked list). Fortunately, all the operations needed to change the dictionary can be done in that way. Bucket resizes are made visible when the new array is assigned back to the m_buckets variable. Any additions or modifications to a node are done by creating a new node, then splicing it into the existing list using a single variable assignment. Node removals are simply done by re-assigning the node's m_next pointer. Because the dictionary can be changed by another thread during execution of the lockless methods, the GetEnumerator method is liable to return dirty reads - changes made to the dictionary after GetEnumerator was called, but before the enumeration got to that point in the dictionary. It's worth listing at this point which methods are lockless, and which take out all the locks in the dictionary to ensure they get a consistent view of the dictionary: Lockless: TryGetValue GetEnumerator The indexer getter ContainsKey Takes out every lock (lockfull?): Count IsEmpty Keys Values CopyTo ToArray Concurrent principles That covers the overall implementation of ConcurrentDictionary. I haven't even begun to scratch the surface of this sophisticated collection. That I leave to you. However, we've looked at enough to be able to extract some useful principles for concurrent programming: Partitioning When using locks, the work is partitioned into independant chunks, each with its own lock. Each partition can then be modified concurrently to other partitions. Ordered lock-taking When a method does need to control the entire collection, locks are taken and released in a fixed order to prevent deadlocks. Lockless reads Read operations that don't care about dirty reads don't take out any lock; the rest of the collection is implemented so that any reading thread always has a consistent view of the collection. That leads us to the final collection in this little series - ConcurrentBag. Lacking a non-concurrent analogy, it is quite different to any other collection in the class libraries. Prepare your thinking hats!

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• CodePlex Daily Summary for Wednesday, November 16, 2011

  CodePlex Daily Summary for Wednesday, November 16, 2011Popular ReleasesMVC Controls Toolkit: Mvc Controls Toolkit 1.5.5: Added: Now the DateRanteAttribute accepts complex expressions containing "Now" and "Today" as static minimum and maximum. Menu, MenuFor helpers capable of handling a "currently selected element". The developer can choose between using a standard nested menu based on a standard SimpleMenuItem class or specifying an item template based on a custom class. Added also helpers to build the tree structure containing all data items the menu takes infos from. Improved the pager. Now the developer ...Public Key Infrastructure PowerShell module: PowerShell PKI Module v0.9.2: Installation guide: Use default installation path to install this module for all users To install this module for current user only — use the following path: %MyDocs%\WindowsPowerShell\Modules Note: you MUST uninstall previously installed module versions. Direct upgrade is not supported! Note: at this time PowerShell 3.0 CTP1 is not supported. Release notes for version 0.9.2: updated and corrected help for several commands. added online help for all commands. Get-CertificationAuthorit...Files Name Copier: 1.0.0.1: Files Name Copier is a simple easy to use utility that allows you to drag and drop any number of files onto it. The clipboard will now contain the list of files you just dropped.SQL Monitor - tracking sql server activities: SQLMon 4.1 alpha 3: 1. improved object search, now show previous/next navigation 2. shows server start up time 3. shows process cpu/ioCODE Framework: 4.0.11115.0: Added support for partial views in the WPF framework, as well as a new helper feature that allows hooking commands/actions to all WPF events.Silverlight Toolkit: Windows Phone Toolkit - Nov 2011 (7.1 SDK): This release is coming soon! What's new ListPicker once again works in a ScrollViewer LongListSelector bug fixes around OutOfRange exceptions, wrong ordering of items, grouping issues, and scrolling events. ItemTuple is now refactored to be the public type LongListSelectorItem to provide users better access to the values in selection changed handlers. PerformanceProgressBar binding fix for IsIndeterminate (item 9767 and others) There is no longer a GestureListener dependency with the C...DotNetNuke® Community Edition: 06.01.01: Major Highlights Fixed problem with the core skin object rendering CSS above the other framework inserted files, which caused problems when using core style skin objects Fixed issue with iFrames getting removed when content is saved Fixed issue with the HTML module removing styling and scripts from the content Fixed issue with inserting the link to jquery after the header of the page Security Fixesnone Updated Modules/Providers ModulesHTML version 6.1.0 ProvidersnoneDotNetNuke Performance Settings: 01.00.00: First release of DotNetNuke SQL update queries to set the DNN installation for optimimal performance. Please review and rate this release... (stars are welcome)SCCM Client Actions Tool: SCCM Client Actions Tool v0.8: SCCM Client Actions Tool v0.8 is currently the latest version. It comes with following changes since last version: Added "Wake On LAN" action. WOL.EXE is now included. Added new action "Get all active advertisements" to list all machine based advertisements on remote computers. Added new action "Get all active user advertisements" to list all user based advertisements for logged on users on remote computers. Added config.ini setting "enablePingTest" to control whether ping test is ru...Windows Azure SDK for PHP: Windows Azure SDK for PHP v4.0.4: INSTALLATION Windows Azure SDK for PHP requires no special installation steps. Simply download the SDK, extract it to the folder you would like to keep it in, and add the library directory to your PHP include_path. INSTALLATION VIA PEAR Maarten Balliauw provides an unofficial PEAR channel via http://www.pearplex.net. Here's how to use it: New installation: pear channel-discover pear.pearplex.net pear install pearplex/PHPAzure Or if you've already installed PHPAzure before: pear upgrade p...QuickGraph, Graph Data Structures And Algorithms for .Net: 3.6.61116.0: Portable library build that allows to use QuickGraph in any .NET environment: .net 4.0, silverlight 4.0, WP7, Win8 Metro apps.Devpad: 4.7: Whats new for Devpad 4.7: New export to Rich Text New export to FlowDocument Minor Bug Fix's, improvements and speed upsDesktop Google Reader: 1.4.2: This release remove the like and the broadcast buttons as Google Reader stopped supporting them (no, we don't like this decission...) Additionally and to have at least a small plus: the login window now automaitcally logs you in if you stored username and passwort (no more extra click needed) Finally added WebKit .NET to the about window and removed Awesomium MD5-Hash: 5fccf25a2fb4fecc1dc77ebabc8d3897 SHA-Hash: d44ff788b123bd33596ad1a75f3b9fa74a862fdbRDRemote: Remote Desktop remote configurator V 1.0.0: Remote Desktop remote configurator V 1.0.0Rawr: Rawr 4.2.7: This is the Downloadable WPF version of Rawr!For web-based version see http://elitistjerks.com/rawr.php You can find the version notes at: http://rawr.codeplex.com/wikipage?title=VersionNotes Rawr AddonWe now have a Rawr Official Addon for in-game exporting and importing of character data hosted on Curse. The Addon does not perform calculations like Rawr, it simply shows your exported Rawr data in wow tooltips and lets you export your character to Rawr (including bag and bank items) like Char...VidCoder: 1.2.2: Updated Handbrake core to svn 4344. Fixed the 6-channel discrete mixdown option not appearing for AAC encoders. Added handling for possible exceptions when copying to the clipboard, added retries and message when it fails. Fixed issue with audio bitrate UI not appearing sometimes when switching audio encoders. Added extra checks to protect against reported crashes. Added code to upgrade encoding profiles on old queued items.Media Companion: MC 3.422b Weekly: Ensure .NET 4.0 Full Framework is installed. (Available from http://www.microsoft.com/download/en/details.aspx?id=17718) Ensure the NFO ID fix is applied when transitioning from versions prior to 3.416b. (Details here) TV Show Resolutions... Made the TV Shows folder list sorted. Re-visibled 'Manually Add Path' in Root Folders. Sorted list to process during new tv episode search Rebuild Movies now processes thru folders alphabetically Fix for issue #208 - Display Missing Episodes is not popu...XPath Visualizer: XPathVisualizer v1.3 Latest: This is v1.3.0.6 of XpathVisualizer. This is an update release for v1.3. These workitems have been fixed since v1.3.0.5: 7429 7432 7427MSBuild Extension Pack: November 2011: Release Blog Post The MSBuild Extension Pack November 2011 release provides a collection of over 415 MSBuild tasks. A high level summary of what the tasks currently cover includes the following: System Items: Active Directory, Certificates, COM+, Console, Date and Time, Drives, Environment Variables, Event Logs, Files and Folders, FTP, GAC, Network, Performance Counters, Registry, Services, Sound Code: Assemblies, AsyncExec, CAB Files, Code Signing, DynamicExecute, File Detokenisation, GU...Extensions for Reactive Extensions (Rxx): Rxx 1.2: What's NewRelated Work Items Please read the latest release notes for details about what's new. Content SummaryRxx provides the following features. See the Documentation for details. Many IObservable<T> extension methods and IEnumerable<T> extension methods. Many useful types such as ViewModel, CommandSubject, ListSubject, DictionarySubject, ObservableDynamicObject, Either<TLeft, TRight>, Maybe<T> and others. Various interactive labs that illustrate the runtime behavior of the extensio...New Projects#foo MigratorFoo: Migration generator for NHibernate projects with integrated NuGet console commands.Best music production software: Programmers needed to make the perfect open source music production software: I have a well structured creative idea based on the following principle "powerful simplicity"...Bricks: Bricks is a development foundation for different technologyCultiv Jupiter Contact Form: A contact form package for Umbraco v5 (Jupiter)DNN Fan Gate: A simple module for fan gating content in DotNetNukeDobo: DoboDotNetNuke Performance Settings: A set of SQL queries that will change the (Host & Schedule) settings of your DotNetNuke installation for maximal production performance or set it optimal for Development. These queries were used in my presentation on DotNetNuke World 2011.Experiment Manager: This project was developed as a response to the requirements for an experiment manager software for clinical psychology experiments. Feedbook: Feedbook supports any RSS and Atom news feeds, It can also download podcasts saliently and play it within Feedbook. It integrates with Twitter and Google Buzz very well, you can send tweets/post easily and can also subscribe to twitter timelines/buzz feeds. Characters like # & @ also recognize as special keywords, so that you can subscribe to feeds of any on going topic on twitter like #download, #movie or #cricket. http://feedbook.orgFiles Name Copier: Files Name Copier is a simple easy to use utility that allows you to drag and drop any number of files onto it. The clipboard will now contain the list of files you just dropped.Kinban: Kinect + TFS This is a WPF representation of a Kanban board that can be manipulated with the Kinect.MapTeamsPolls: This is an ASP.Net ajax polls user controls. Using ajax and jQuery. This user controls can be used in any ASP.Net 4.0 projects. Use the build script to create Umbraco package for the user controls and the admin page. As a bonus, there is a ruby rake build script for the package.MetroButton with Converter Image SVG2XAML Silverlight: - Control library SL4 with Button Metro Style - Windows application for download and convert SVG to Resource.xaml for silverlightMetroIoc - a simple WinRT IoC container: A WinRT port of the MicroIoc container... MetroIoc is a native WinRT Inversion of Control container, for use in Metro style apps. Check the license for usage rights of this projectMTN Library: .NET library with extensions for LINQ and Entity Framework as well as useful extensions. Contains many extensions, features for display methods using jquery Ajax. Has a proxy to create and use methods with cache as much as in the ajax methods.myDeck: Main goal of this project is to show best practices and patterns for unit testing in Silverlight Technology. It is developed as part of BAThesisNetwork extensions for .net Micro Framework and Gadgeteer: Adds .net Microframework support for - BinaryReader - BinaryWriter Adds a FEZ way for TCP and UDP networking to the Gadgeteer platformNewSunse: this card creating projectOrchard CMS ImageResizer: resize or scale images in orchard simply by url or using the build-in HtmlHelperReportCenter: ReportCenterSharePoint 2010 Extended Lookup Field: This project installs a custom lookup field, which allows the user to choose the item through a SharePoint 2010 popup. Here are the features offered by this field: - high extensibility - high performance when woking with very large lists - small size for new and edit list forms - posibility to specify you own search page - SharePoint 2010 lookup and feel The project is a VS2010 SharePoint 2010 project. Simplicity Framework: Simplicity is a framework to automatic generate dataccess an UI code for crudlstackoverflowstore: Homenaje a stackoverflow.Stoc: Aplicatia Stoc simplifica generarea facturilor si a retelor, gestionand stocul marfii unei firme. Student PAS: Student PAS is a simple webapp for assign tasks for students. It was created with educational purposes. Thus, it is not an serious usable software.System Center 2012 - Operations Manager Managed Module Samples: Sample Visual Studio 2010 projects that illustrate how you can create custom module types for System Center 2012 - Operations Manager. The project contains the C# code for creating data source, write action, probe and condition detection modules and more.Tecnosop: Sistema de facturacion de TecnosopUtilityLibrary.FormControl: FormControlWebRequestFrequencyControl: This project intends to solve the web request frequency control problem. This solution is based on HttpModule and highly configurable. If you need to limit the frequency of requests, you may interest in this.Windows Phone Marketplace Analytics: Libraries (and data) to help you access and analyze the different information provided by the MS marketplace.Windows Troubleshooting Platform Starter Packs: Starter Packs are open source packages based on the Windows Troubleshooting Platform that can be modified by developers to suit their specific needs. Starter Packs are an easy way for developers to create and distribute a Windows Troubleshooting Pack to diagnose computer problems.

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• Picker view wont rotate- iPhone

  - by lotuseater

  hi, I am making a booking page. I have included 3 pickers in it. I have included all the delegates required for the pickers to work but it wont rotate. I have enabled user interaction and multitouch in the nib file. Here is my code. Please help me. :( @interface ChooseContactsFrom : UIViewController { IBOutlet UIPickerView *statePickup; IBOutlet UIPickerView *paymentMethodPickup; IBOutlet UIDatePicker *expiryDatePickup; IBOutlet UIView *statePickupView; IBOutlet UIView *paymentMethodPickupView; IBOutlet UIView *expiryDatePickupView; } (void)viewDidLoad { self.title = @"Choose Contacts"; //Fill in the states name/ stateArray = [[NSArray alloc]initWithObjects:@"",nil]; paymentModeArray = [[NSArray alloc] initWithObjects:@"Credit Card", @"Cash",@"Account",@"Voucher",@"Debit Card", nil]; paymentMethodPickup.frame = CGRectMake(0.0, 44.0, paymentMethodPickup.frame.size.width, paymentMethodPickup.frame.size.height); paymentMethodPickup.userInteractionEnabled = YES; paymentMethodPickup.multipleTouchEnabled = YES; paymentMethodPickupView.frame = CGRectMake(0.0, 210.0, paymentMethodPickupView.frame.size.width, paymentMethodPickupView.frame.size.height); statePickup.frame = CGRectMake(0.0, 44.0,statePickup.frame.size.width, statePickup.frame.size.height); statePickupView.frame = CGRectMake(0.0, 210.0, statePickupView.frame.size.width, statePickupView.frame.size.height); stateArray = [[NSArray alloc] initWithObjects:@"state1", @"state2", @"state3", @"state4", @"state5", @"state6", @"state7", @"state8", @"state9", @"state10", nil]; expiryDatePickup.frame = CGRectMake(0.0, 44.0, expiryDatePickup.frame.size.width, expiryDatePickup.frame.size.height); expiryDatePickupView.frame = CGRectMake(0.0, 210.0, expiryDatePickupView.frame.size.width, expiryDatePickupView.frame.size.height); [super viewDidLoad]; } -(IBAction)back:(id)sender { [self dismissModalViewControllerAnimated:YES]; } pragma mark pickerView delegates (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)thePickerView { return 1; } (NSInteger)pickerView:(UIPickerView *)thePickerView numberOfRowsInComponent:(NSInteger)component { if( thePickerView == statePickup) { return [stateArray count]; } else if(thePickerView == paymentMethodPickup) { return [paymentModeArray count]; } else { return 0; } } (NSString *)pickerView:(UIPickerView *)thePickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component { if(thePickerView == statePickup) { return [stateArray objectAtIndex:row]; } else if(thePickerView == paymentMethodPickup) { return [paymentModeArray objectAtIndex:row]; } else { return @" "; } } (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component{ return 50; } (CGFloat)pickerView:(UIPickerView *)pickerView widthForComponent:(NSInteger)component { return 250; } (void)pickerView:(UIPickerView *)thepickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component { if(thepickerView == statePickup) { state.text=[stateArray objectAtIndex:row]; } if(thepickerView == paymentMethodPickup) { payment.text=[paymentModeArray objectAtIndex:row]; } } (void)ClearSubviews { //[firstName resignFirstResponder]; // [lastName resignFirstResponder]; // [email resignFirstResponder]; // [address1 resignFirstResponder]; // [address2 resignFirstResponder]; // [city resignFirstResponder]; // //[state resignFirstResponder]; // [payment resignFirstResponder]; // [creditCard resignFirstResponder]; // [expirydate removeFromSuperview]; // [statePickup removeFromSuperview]; // [paymentMethodPickup removeFromSuperview]; } (BOOL)textFieldShouldBeginEditing:(UITextField *)textField { // [self showPicker:textField]; //[self setViewMovedUp]; if(textField == firstName || textField == lastName || textField == email || textField == address1 || textField == address2 ||textField == city) { [self ClearSubviews]; //pickerToolbar.hidden = TRUE; return YES; } else if(textField == payment) { [self ClearSubviews]; [self setViewMovedUp]; [payment setText:[paymentModeArray objectAtIndex:0]]; [self.view insertSubview:paymentMethodPickupView aboveSubview:self.view]; return NO; } else if(textField == state) { [self ClearSubviews]; [self setViewMovedUp]; [state setText:[stateArray objectAtIndex:0]]; [self.view insertSubview:statePickupView aboveSubview:self.view]; return NO; } else if(textField == expirydate) { [self setViewMovedUp]; expiryDatePickup.date = [NSDate date]; NSDate *date1 = [NSDate date]; NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateStyle:NSDateFormatterMediumStyle]; NSString *strDate=[dateFormatter stringFromDate:date1]; NSString *str=[[NSString alloc] initWithString: strDate]; [expirydate setText:str]; [self.view insertSubview:expiryDatePickupView aboveSubview:self.view]; return NO; } else if(textField == creditCard) { [self ClearSubviews]; [self setViewMovedUp]; return YES; } else { [self ClearSubviews]; return YES; } } -(BOOL)textFieldShouldEndEditing:(UITextField *)textField { return YES; } (void)textFieldDidEndEditing:(UITextField *)textField { if(textField == creditCard) { [self moveDown]; } } (BOOL)textFieldShouldReturn:(UITextField *)textField { [firstName resignFirstResponder]; [lastName resignFirstResponder]; [email resignFirstResponder]; [address1 resignFirstResponder]; [address2 resignFirstResponder]; [city resignFirstResponder]; [creditCard resignFirstResponder]; return YES; } -(IBAction)textFieldDoneEditing:(id)sender { [sender resignFirstResponder]; } ////////----------------------------------------------------------------------- pragma mark move screen (void)setViewMovedUp { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.3]; // Make changes to the view's frame inside the animation block. They will be animated instead // of taking place immediately. CGRect rect = [self.view frame]; // If moving up, not only decrease the origin but increase the height so the view // covers the entire screen behind the keyboard. rect.origin.y -= 50.0f; rect.size.height -= 80.0f; [self.view setFrame:rect]; [UIView commitAnimations]; } -(void)moveDown { [UIView beginAnimations:nil context:NULL]; [UIView setAnimationDuration:0.3]; // Make changes to the view's frame inside the animation block. They will be animated instead // of taking place immediately. CGRect rect = [self.view frame]; rect.origin.y += 50.0f; rect.size.height += 80.0f; [self.view setFrame:rect]; // [UIView setBackgroundColor:[UIColor darkGrayColor]]; [UIView commitAnimations]; } pragma mark Method to show pickers -(void)showPicker:(UITextField *)textField { if(textField == expirydate) { expiryDatePickup .date = [NSDate date]; NSDate *date1 = [NSDate date]; NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateStyle:NSDateFormatterMediumStyle]; NSString *strDate=[dateFormatter stringFromDate:date1]; NSString *str=[[NSString alloc] initWithString: strDate]; [expirydate setText:str]; [self.view insertSubview:expiryDatePickup aboveSubview:self.view]; } else if(textField == payment) { [payment setText:[paymentModeArray objectAtIndex:0]]; [self.view insertSubview:paymentMethodPickupView aboveSubview:self.view]; } else if(textField == state) { [state setText:[stateArray objectAtIndex:0]]; [self.view insertSubview:statePickupView aboveSubview:self.view]; } } (IBAction)datePickerChanged:(id)sender { NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateStyle:NSDateFormatterMediumStyle]; NSDate *date=expiryDatePickup.date; formattedDateString1 = [dateFormatter stringFromDate:date]; [expirydate setText:formattedDateString1]; NSCalendar *gregorian = [[NSCalendar alloc] initWithCalendarIdentifier:NSGregorianCalendar]; unsigned int unitFlags = NSMonthCalendarUnit | NSDayCalendarUnit; components = [gregorian components:unitFlags fromDate:date]; [gregorian release]; } pragma mark done and cancel methods -(IBAction) btnCancelExpiryDate:(id)sender { [self moveDown]; [expirydate setText:@" "]; [expiryDatePickupView removeFromSuperview]; } -(IBAction) btnDoneExpiryDate:(id)sender { [self moveDown]; [expiryDatePickupView removeFromSuperview]; expiryDatePickup .date = [NSDate date]; } -(IBAction)cancelPaymentType:(id)sender { [self moveDown]; [payment setText:@" "]; [paymentMethodPickupView removeFromSuperview]; } -(IBAction)donePaymentType:(id)sender { [self moveDown]; [paymentMethodPickupView removeFromSuperview]; } -(IBAction)doneState:(id)sender { [self moveDown]; [statePickupView removeFromSuperview]; } (IBAction)cancelState:(id)sender; { [self moveDown]; [state setText:@" "]; [statePickupView removeFromSuperview]; }

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• iPhone SDK Tableview Datasource singleton error

  - by mrburns05

  I basically followed apple "TheElements" sample and changed "PeriodicElements" .h & .m to my own "SortedItems" .h & .m During compile I get this error: "Undefined symbols: "_OBJC_CLASS_$_SortedItems", referenced from: __objc_classrefs__DATA@0 in SortedByNameTableDataSource.o ld: symbol(s) not found collect2: ld returned 1 exit status " here is my SortedItems.m file #import "SortedItems.h" #import "item.h" #import "MyAppDelegate.h" @interface SortedItems(mymethods) // these are private methods that outside classes need not use - (void)presortItemsByPhysicalState; - (void)presortItemInitialLetterIndexes; - (void)presortItemNamesForInitialLetter:(NSString *)aKey; - (void)presortItemsWithPhysicalState:(NSString *)state; - (NSArray *)presortItemsByNumber; - (NSArray *)presortItemsBySymbol; - (void)setupItemsArray; @end @implementation SortedItems @synthesize statesDictionary; @synthesize itemsDictionary; @synthesize nameIndexesDictionary; @synthesize itemNameIndexArray; @synthesize itemsSortedByNumber; @synthesize itemsSortedBySymbol; @synthesize itemPhysicalStatesArray; static SortedItems *sharedSortedItemsInstance = nil; + (SortedItems*)sharedSortedItems { @synchronized(self) { if (sharedSortedItemsInstance == nil) { [[self alloc] init]; // assignment not done here } } return sharedSortedItemsInstance; // note: Xcode (3.2) static analyzer will report this singleton as a false positive // '(Potential leak of an object allocated') } + (id)allocWithZone:(NSZone *)zone { @synchronized(self) { if (sharedSortedItemsInstance == nil) { sharedSortedItemsInstance = [super allocWithZone:zone]; return sharedSortedItemsInstance; // assignment and return on first allocation } } return nil; //on subsequent allocation attempts return nil } - (id)copyWithZone:(NSZone *)zone { return self; } - (id)retain { return self; } - (unsigned)retainCount { return UINT_MAX; //denotes an object that cannot be released } - (void)release { //do nothing } - (id)autorelease { return self; } // setup the data collection - init { if (self = [super init]) { [self setupItemsArray]; } return self; } - (void)setupItemsArray { NSDictionary *eachItem; // create dictionaries that contain the arrays of Item data indexed by // name self.itemsDictionary = [NSMutableDictionary dictionary]; // physical state self.statesDictionary = [NSMutableDictionary dictionary]; // unique first characters (for the Name index table) self.nameIndexesDictionary = [NSMutableDictionary dictionary]; // create empty array entries in the states Dictionary or each physical state [statesDictionary setObject:[NSMutableArray array] forKey:@"Solid"]; [statesDictionary setObject:[NSMutableArray array] forKey:@"Liquid"]; [statesDictionary setObject:[NSMutableArray array] forKey:@"Gas"]; [statesDictionary setObject:[NSMutableArray array] forKey:@"Artificial"]; MyAppDelegate *ad = (MyAppDelegate *)[[UIApplication sharedApplication]delegate]; NSMutableArray *rawItemsArray = [[NSMutableArray alloc] init]; [rawItemsArray addObjectsFromArray:ad.items]; // iterate over the values in the raw Items dictionary for (eachItem in rawItemsArray) { // create an atomic Item instance for each Item *anItem = [[Item alloc] initWithDictionary:eachItem]; // store that item in the Items dictionary with the name as the key [itemsDictionary setObject:anItem forKey:anItem.title]; // add that Item to the appropriate array in the physical state dictionary [[statesDictionary objectForKey:anItem.acct] addObject:anItem]; // get the Item's initial letter NSString *firstLetter = [anItem.title substringToIndex:1]; NSMutableArray *existingArray; // if an array already exists in the name index dictionary // simply add the Item to it, otherwise create an array // and add it to the name index dictionary with the letter as the key if (existingArray = [nameIndexesDictionary valueForKey:firstLetter]) { [existingArray addObject:anItem]; } else { NSMutableArray *tempArray = [NSMutableArray array]; [nameIndexesDictionary setObject:tempArray forKey:firstLetter]; [tempArray addObject:anItem]; } // release the Item, it is held by the various collections [anItem release]; } // release the raw Item data [rawItemsArray release]; // create the dictionary containing the possible Item states // and presort the states data self.itemPhysicalStatesArray = [NSArray arrayWithObjects:@"something",@"somethingElse",@"whatever",@"stuff",nil]; [self presortItemsByPhysicalState]; // presort the dictionaries now // this could be done the first time they are requested instead [self presortItemInitialLetterIndexes]; self.itemsSortedByNumber = [self presortItemsByNumber]; self.itemsSortedBySymbol = [self presortItemsBySymbol]; } // return the array of Items for the requested physical state - (NSArray *)itemsWithPhysicalState:(NSString*)aState { return [statesDictionary objectForKey:aState]; } // presort each of the arrays for the physical states - (void)presortItemsByPhysicalState { for (NSString *stateKey in itemPhysicalStatesArray) { [self presortItemsWithPhysicalState:stateKey]; } } - (void)presortItemsWithPhysicalState:(NSString *)state { NSSortDescriptor *nameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"title" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)] ; NSArray *descriptors = [NSArray arrayWithObject:nameDescriptor]; [[statesDictionary objectForKey:state] sortUsingDescriptors:descriptors]; [nameDescriptor release]; } // return an array of Items for an initial letter (ie A, B, C, ...) - (NSArray *)itemsWithInitialLetter:(NSString*)aKey { return [nameIndexesDictionary objectForKey:aKey]; } // presort the name index arrays so the items are in the correct order - (void)presortItemsInitialLetterIndexes { self.itemNameIndexArray = [[nameIndexesDictionary allKeys] sortedArrayUsingSelector:@selector(localizedCaseInsensitiveCompare:)]; for (NSString *eachNameIndex in itemNameIndexArray) { [self presortItemNamesForInitialLetter:eachNameIndex]; } } - (void)presortItemNamesForInitialLetter:(NSString *)aKey { NSSortDescriptor *nameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"title" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)] ; NSArray *descriptors = [NSArray arrayWithObject:nameDescriptor]; [[nameIndexesDictionary objectForKey:aKey] sortUsingDescriptors:descriptors]; [nameDescriptor release]; } // presort the ItemsSortedByNumber array - (NSArray *)presortItemsByNumber { NSSortDescriptor *nameDescriptor = [[NSSortDescriptor alloc] initWithKey:@"acct" ascending:YES selector:@selector(compare:)] ; NSArray *descriptors = [NSArray arrayWithObject:nameDescriptor]; NSArray *sortedItems = [[itemsDictionary allValues] sortedArrayUsingDescriptors:descriptors]; [nameDescriptor release]; return sortedItems; } // presort the itemsSortedBySymbol array - (NSArray *)presortItemsBySymbol { NSSortDescriptor *symbolDescriptor = [[NSSortDescriptor alloc] initWithKey:@"title" ascending:YES selector:@selector(localizedCaseInsensitiveCompare:)] ; NSArray *descriptors = [NSArray arrayWithObject:symbolDescriptor]; NSArray *sortedItems = [[itemsDictionary allValues] sortedArrayUsingDescriptors:descriptors]; [symbolDescriptor release]; return sortedItems; } @end I followed the sample exactly - don't know where I went wrong. Here is my "SortedByNameTableDataSource.m" #import "SortedByNameTableDataSource.h" #import "SortedItems.h" #import "Item.h" #import "ItemCell.h" #import "GradientView.h" #import "UIColor-Expanded.h" #import "MyAppDelegate.h" @implementation SortedByNameTableDataSource - (NSString *)title { return @"Title"; } - (UITableViewStyle)tableViewStyle { return UITableViewStylePlain; }; // return the atomic element at the index - (Item *)itemForIndexPath:(NSIndexPath *)indexPath { return [[[SortedItems sharedSortedItems] itemsWithInitialLetter:[[[SortedItems sharedSortedItems] itemNameIndexArray] objectAtIndex:indexPath.section]] objectAtIndex:indexPath.row]; } // UITableViewDataSource methods - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *MyIdentifier = @"ItemCell"; ItemCell *itemCell = (ItemCell *)[tableView dequeueReusableCellWithIdentifier:MyIdentifier]; if (itemCell == nil) { itemCell = [[[ItemCell alloc] initWithFrame:CGRectZero reuseIdentifier:MyIdentifier] autorelease]; itemCell = CGRectMake(0.0, 0.0, 320.0, ROW_HEIGHT); itemCell.backgroundView = [[[GradientView alloc] init] autorelease]; } itemCell.todo = [self itemForIndexPath:indexPath]; return itemCell; } - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { // this table has multiple sections. One for each unique character that an element begins with // [A,B,C,D,E,F,G,H,I,K,L,M,N,O,P,R,S,T,U,V,X,Y,Z] // return the count of that array return [[[SortedItems sharedSortedItems] itemNameIndexArray] count]; } - (NSArray *)sectionIndexTitlesForTableView:(UITableView *)tableView { // returns the array of section titles. There is one entry for each unique character that an element begins with // [A,B,C,D,E,F,G,H,I,K,L,M,N,O,P,R,S,T,U,V,X,Y,Z] return [[SortedItems sharedSortedItems] itemNameIndexArray]; } - (NSInteger)tableView:(UITableView *)tableView sectionForSectionIndexTitle:(NSString *)title atIndex:(NSInteger)index { return index; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { // the section represents the initial letter of the element // return that letter NSString *initialLetter = [[[SortedItems sharedSortedItems] itemNameIndexArray] objectAtIndex:section]; // get the array of elements that begin with that letter NSArray *itemsWithInitialLetter = [[SortedItems sharedSortedItems] itemsWithInitialLetter:initialLetter]; // return the count return [itemsWithInitialLetter count]; } - (NSString *)tableView:(UITableView *)tableView titleForHeaderInSection:(NSInteger)section { // this table has multiple sections. One for each unique character that an element begins with // [A,B,C,D,E,F,G,H,I,K,L,M,N,O,P,R,S,T,U,V,X,Y,Z] // return the letter that represents the requested section // this is actually a delegate method, but we forward the request to the datasource in the view controller return [[[SortedItems sharedSortedItems] itemNameIndexArray] objectAtIndex:section]; } @end

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• With a jquery modular dialog how do I stop the form values from persisting?

  - by stormist

  (Citing source at: http://jqueryui.com/demos/dialog/#modal-form) As an example, this works great but each time the form is subsequently opened the user entered values remain. How can I stop this behavior? (the form will be used multiple times on the same page. <style type="text/css"> body { font-size: 62.5%; } label, input { display:block; } input.text { margin-bottom:12px; width:95%; padding: .4em; } fieldset { padding:0; border:0; margin-top:25px; } h1 { font-size: 1.2em; margin: .6em 0; } div#users-contain { width: 350px; margin: 20px 0; } div#users-contain table { margin: 1em 0; border-collapse: collapse; width: 100%; } div#users-contain table td, div#users-contain table th { border: 1px solid #eee; padding: .6em 10px; text-align: left; } .ui-dialog .ui-state-error { padding: .3em; } .validateTips { border: 1px solid transparent; padding: 0.3em; } </style> <script type="text/javascript"> $(function() { // a workaround for a flaw in the demo system (http://dev.jqueryui.com/ticket/4375), ignore! $("#dialog").dialog("destroy"); var name = $("#name"), email = $("#email"), password = $("#password"), allFields = $([]).add(name).add(email).add(password), tips = $(".validateTips"); function updateTips(t) { tips .text(t) .addClass('ui-state-highlight'); setTimeout(function() { tips.removeClass('ui-state-highlight', 1500); }, 500); } function checkLength(o,n,min,max) { if ( o.val().length > max || o.val().length < min ) { o.addClass('ui-state-error'); updateTips("Length of " + n + " must be between "+min+" and "+max+"."); return false; } else { return true; } } function checkRegexp(o,regexp,n) { if ( !( regexp.test( o.val() ) ) ) { o.addClass('ui-state-error'); updateTips(n); return false; } else { return true; } } $("#dialog-form").dialog({ autoOpen: false, height: 300, width: 350, modal: true, buttons: { 'Create an account': function() { var bValid = true; allFields.removeClass('ui-state-error'); bValid = bValid && checkLength(name,"username",3,16); bValid = bValid && checkLength(email,"email",6,80); bValid = bValid && checkLength(password,"password",5,16); bValid = bValid && checkRegexp(name,/^[a-z]([0-9a-z_])+$/i,"Username may consist of a-z, 0-9, underscores, begin with a letter."); // From jquery.validate.js (by joern), contributed by Scott Gonzalez: http://projects.scottsplayground.com/email_address_validation/ bValid = bValid && checkRegexp(email,/^((([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+(\.([a-z]|\d|[!#\$%&'\*\+\-\/=\?\^_`{\|}~]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])+)*)|((\x22)((((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(([\x01-\x08\x0b\x0c\x0e-\x1f\x7f]|\x21|[\x23-\x5b]|[\x5d-\x7e]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(\\([\x01-\x09\x0b\x0c\x0d-\x7f]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF]))))*(((\x20|\x09)*(\x0d\x0a))?(\x20|\x09)+)?(\x22)))@((([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|\d|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.)+(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])|(([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])([a-z]|\d|-|\.|_|~|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])*([a-z]|[\u00A0-\uD7FF\uF900-\uFDCF\uFDF0-\uFFEF])))\.?$/i,"eg. [email protected]"); bValid = bValid && checkRegexp(password,/^([0-9a-zA-Z])+$/,"Password field only allow : a-z 0-9"); if (bValid) { $('#users tbody').append('<tr>' + '<td>' + name.val() + '</td>' + '<td>' + email.val() + '</td>' + '<td>' + password.val() + '</td>' + '</tr>'); $(this).dialog('close'); } }, Cancel: function() { $(this).dialog('close'); } }, close: function() { allFields.val('').removeClass('ui-state-error'); } }); $('#create-user') .button() .click(function() { $('#dialog-form').dialog('open'); }); }); </script> <div class="demo"> <div id="dialog-form" title="Create new user"> <p class="validateTips">All form fields are required.</p> <form> <fieldset> <label for="name">Name</label> <input type="text" name="name" id="name" class="text ui-widget-content ui-corner-all" /> <label for="email">Email</label> <input type="text" name="email" id="email" value="" class="text ui-widget-content ui-corner-all" /> <label for="password">Password</label> <input type="password" name="password" id="password" value="" class="text ui-widget-content ui-corner-all" /> </fieldset> </form> </div> <div id="users-contain" class="ui-widget"> <h1>Existing Users:</h1> <table id="users" class="ui-widget ui-widget-content"> <thead> <tr class="ui-widget-header "> <th>Name</th> <th>Email</th> <th>Password</th> </tr> </thead> <tbody> <tr> <td>John Doe</td> <td>[email protected]</td> <td>johndoe1</td> </tr> </tbody> </table> </div> <button id="create-user">Create new user</button> </div><!-- End demo --> <div class="demo-description"> <p>Use a modal dialog to require that the user enter data during a multi-step process. Embed form markup in the content area, set the <code>modal</code> option to true, and specify primary and secondary user actions with the <code>buttons</code> option.</p> </div><!-- End demo-description -->

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• Communicating between C# application and Android app via bluetooth

  - by Akki

  The android application acts as a server in this case. I have a main activity which creates a Thread to handle serverSocket and a different thread to handle the socket connection. I am using a uuid common to C# and android. I am using 32feet bluetooth library for C#. The errors i am facing are 1) My logcat shows this debug log Error while doing socket.connect()1 java.io.IOException: File descriptor in bad state Message: File descriptor in bad state Localized Message: File descriptor in bad state Received : Testing Connection Count of Thread is : 1 2) When i try to send something via C# app the second time, this exception is thrown: A first chance exception of type 'System.InvalidOperationException' occurred in System.dll System.InvalidOperationException: BeginConnect cannot be called while another asynchronous operation is in progress on the same Socket. at System.Net.Sockets.Socket.DoBeginConnect(EndPoint endPointSnapshot, SocketAddress socketAddress, LazyAsyncResult asyncResult) at System.Net.Sockets.Socket.BeginConnect(EndPoint remoteEP, AsyncCallback callback, Object state) at InTheHand.Net.Bluetooth.Msft.SocketBluetoothClient.BeginConnect(BluetoothEndPoint remoteEP, AsyncCallback requestCallback, Object state) at InTheHand.Net.Sockets.BluetoothClient.BeginConnect(BluetoothEndPoint remoteEP, AsyncCallback requestCallback, Object state) at InTheHand.Net.Sockets.BluetoothClient.BeginConnect(BluetoothAddress address, Guid service, AsyncCallback requestCallback, Object state) at BTSyncClient.Form1.connect() in c:\users\----\documents\visual studio 2010\Projects\TestClient\TestClient\Form1.cs:line 154 I only know android application programming and i designed the C# by learning bit and pieces. FYI, My android phone is galaxy s with ICS running on it.Please point out my mistakes.. Source codes : C# Code using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Threading; using System.Net.Sockets; using InTheHand.Net.Bluetooth; using InTheHand.Windows.Forms; using InTheHand.Net.Sockets; using InTheHand.Net; namespace BTSyncClient { public partial class Form1 : Form { BluetoothClient myself; BluetoothDeviceInfo bTServerDevice; private Guid uuid = Guid.Parse("00001101-0000-1000-8000-00805F9B34FB"); bool isConnected; public Form1() { InitializeComponent(); if (BluetoothRadio.IsSupported) { myself = new BluetoothClient(); } } private void Form1_Load(object sender, EventArgs e) { } private void button1_Click(object sender, EventArgs e) { connect(); } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { try { myself.GetStream().Close(); myself.Dispose(); } catch (Exception ex) { Console.Out.WriteLine(ex); } } private void button2_Click(object sender, EventArgs e) { SelectBluetoothDeviceDialog dialog = new SelectBluetoothDeviceDialog(); DialogResult result = dialog.ShowDialog(this); if(result.Equals(DialogResult.OK)){ bTServerDevice = dialog.SelectedDevice; } } private void callback(IAsyncResult ar) { String msg = (String)ar.AsyncState; if (ar.IsCompleted) { isConnected = myself.Connected; if (myself.Connected) { UTF8Encoding encoder = new UTF8Encoding(); NetworkStream stream = myself.GetStream(); if (!stream.CanWrite) { MessageBox.Show("Stream is not Writable"); } System.IO.StreamWriter mywriter = new System.IO.StreamWriter(stream, Encoding.UTF8); mywriter.WriteLine(msg); mywriter.Flush(); } else MessageBox.Show("Damn thing isnt connected"); } } private void connect() { try { if (bTServerDevice != null) { myself.BeginConnect(bTServerDevice.DeviceAddress, uuid, new AsyncCallback(callback) , message.Text); } } catch (Exception e) { Console.Out.WriteLine(e); } } } } Server Thread import java.io.IOException; import java.util.UUID; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothServerSocket; import android.bluetooth.BluetoothSocket; import android.util.Log; public class ServerSocketThread extends Thread { private static final String TAG = "TestApp"; private BluetoothAdapter btAdapter; private BluetoothServerSocket serverSocket; private boolean stopMe; private static final UUID uuid = UUID.fromString("00001101-0000-1000-8000-00805F9B34FB"); //private static final UUID uuid = UUID.fromString("6e58c9d5-b0b6-4009-ad9b-fd9481aef9b3"); private static final String SERVICE_NAME = "TestService"; public ServerSocketThread() { stopMe = false; btAdapter = BluetoothAdapter.getDefaultAdapter(); try { serverSocket = btAdapter.listenUsingRfcommWithServiceRecord(SERVICE_NAME, uuid); } catch (IOException e) { Log.d(TAG,e.toString()); } } public void signalStop(){ stopMe = true; } public void run(){ Log.d(TAG,"In ServerThread"); BluetoothSocket socket = null; while(!stopMe){ try { socket = serverSocket.accept(); } catch (IOException e) { break; } if(socket != null){ AcceptThread newClientConnection = new AcceptThread(socket); newClientConnection.start(); } } Log.d(TAG,"Server Thread now dead"); } // Will cancel the listening socket and cause the thread to finish public void cancel(){ try { serverSocket.close(); } catch (IOException e) { } } } Accept Thread import java.io.IOException; import java.io.InputStream; import java.util.Scanner; import android.bluetooth.BluetoothSocket; import android.util.Log; public class AcceptThread extends Thread { private BluetoothSocket socket; private String TAG = "TestApp"; static int count = 0; public AcceptThread(BluetoothSocket Socket) { socket = Socket; } volatile boolean isError; String output; String error; public void run() { Log.d(TAG, "AcceptThread Started"); isError = false; try { socket.connect(); } catch (IOException e) { Log.d(TAG,"Error while doing socket.connect()"+ ++count); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } InputStream in = null; try { in = socket.getInputStream(); } catch (IOException e) { Log.d(TAG,"Error while doing socket.getInputStream()"); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } Scanner istream = new Scanner(in); if (istream.hasNextLine()) { Log.d(TAG, "Received : "+istream.nextLine()); Log.d(TAG,"Count of Thread is : " + count); } istream.close(); try { in.close(); } catch (IOException e) { Log.d(TAG,"Error while doing in.close()"); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } try { socket.close(); } catch (IOException e) { Log.d(TAG,"Error while doing socket.close()"); Log.d(TAG, e.toString()); Log.d(TAG,"Message: "+e.getLocalizedMessage()); Log.d(TAG,"Localized Message: "+e.getMessage()); isError = true; } } }

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