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  • This task is currently locked by a running workflow and cannot be edited. Limitation to both Nintex and SPD workflow

    - by ybbest
    Note, this post is from Nintex Forum here. These limitations apply to both SharePoint designer Workflow and Nintex Workflow as Nintex using the SharePoint workflow engine. The common cause that I experience is that ‘parent’ workflow is generating more than one task at once. This is common as you can have multiple approvers for certain approval process. You could also have workflow running when the task is created, one of the common scenario is you would like to set a custom column value in your approval task. For me this is huge limitation, as Nintex lover I really hope Nintex could solve this problem with Microsoft going forward. Introduction “This task is currently locked by a running workflow and cannot be edited” is a common message that is seen when an error occurs while the SharePoint workflow engine is processing a task item associated with a workflow. When a workflow processes a task normally, the following sequence of events is expected to occur: 1.       The process begins. 2.       The workflow places a ‘lock’ on the task so nothing else can change the values while the workflow is processing. 3.       The workflow processes the task. 4.       The lock is released when the task processing is finished. When the message is encountered, it usually indicates that an error occurred between step 2 and 4. As a result, the lock is never released. Therefore, the ‘task locked’ message is not an error itself, rather a symptom of another error – the ‘task locked’ message does not indicate what went wrong. In most cases, once this message is encountered, the workflow cannot be made to continue and must be terminated and started again. The following is a guide that can help troubleshoot the cause of these messages.  Some initial observations to narrow down the potential causes are: Is the error consistent or intermittent? When the error is consistent, it will happen every time the workflow is run. When it is intermittent, it may happen regularly, but not every time. Does the error occur the first time the user tries to respond to a task, or do they respond and notice the workflow does not continue, and when they respond again the error occurs? If the message is present when the user first responds to the task, the issue would have occurred when the task was created. Otherwise, it would have occurred when the user attempted to respond to the task. Causes Modifying the task list A cause of this error appearing consistently the first time a user tries to respond to a task is a modification to the default task list schema. For example, changing the ‘Assigned to’ field in a task list to be a multiple selection will cause the behaviour. Deleting the workflow task then restoring it from the Recycle bin If you start a workflow, delete the workflow task then restore it from the Recycle Bin in SharePoint, the workflow will fail with the ‘task locked’ error.  This is confirmed behaviour whether using a SharePoint Designer or a Nintex workflow.  You will need to terminate the workflow and start it again. Parallel simultaneous responses A cause of this error appearing inconsistently is multiple users responding to tasks in parallel at the same time. In this scenario, one task will complete correctly and the other will not process. When the user tries again, the ‘task locked’ message will display. Nintex included a workaround for this issue in build 11000. In build 11000 and later, one of the users will receive a message on the task form when they attempt to respond, stating that they need to try again in a few moments. Additional processing on the task A cause of this error appearing consistently and inconsistently is having an additional system running on the items in the task list. Some examples include: a workflow running on the task list, an event receiver running on the task list or another automated process querying and updating workflow tasks. Note: This Microsoft help article (http://office.microsoft.com/en-us/sharepointdesigner/HA102376561033.aspx#5) explains creating a workflow that runs on the task list to update a field on the task. Our experience shows that this causes the ‘Task Locked’ issues when the ‘parent’ workflow is generating more than one task at once. Isolated system error If the error is a rare event, or a ‘one off’ event, then an isolated system error may have occurred. For example, if there is a database connectivity issue while the workflow is processing the task response, the task will lock. In this case, the user will respond to a task but the workflow will not continue. When they respond again, the ‘task locked’ message will display. In this case, there will be an error in the SharePoint ULS Logs at the time that the user originally responded. Temporary delay while workflow processes If the workflow is taking a long time to process after a user submits a task, they may notice and try to respond to the task again. They will see the task locked error, but after a number of attempts (or after waiting some time) the task response page eventually indicates the task has been responded to. In this case, nothing actually went wrong, and the error message gives an accurate indication of what is happening – the workflow temporarily locked the task while it was processing. This scenario may occur in a very large workflow, or after the SharePoint application pool has just started. Modifying the task via a web service with an invalid url If the Nintex Workflow web service is used to respond to or delegate a task, the site context part of the url must be a valid alternative access mapping url. For example, if you access the web service via the IP address of the SharePoint server, and the IP address is not a valid AAM, the task can become locked. The workflow has become stuck without any apparent errors This behaviour can occur as a result of a bug in the SharePoint 2010 workflow engine.  If you do not have the August 2010 Cumulative Update (or later) for SharePoint, and your workflow uses delays, “Flexi-task”, State machine”, “Task Reminder” actions or variables, you could be affected. Check the SharePoint 2010 Updates site here: http://technet.microsoft.com/en-us/sharepoint/ff800847.  The October CU is recommended http://support.microsoft.com/kb/2553031.   The fix is described as “Consider the following scenario. You add a Delay activity to a workflow. Then, you set the duration for the Delay activity. You deploy the workflow in SharePoint Foundation 2010. In this scenario, the workflow is not resumed after the duration of the Delay activity”. If you find this is occurring in your environment, install the October CU, terminate all the running workflows affected and run them afresh. Investigative steps The first step to isolate the issue is to create a new task list on the site and configure the workflow to use it.  Any customizations that were made to the original task list should not be made to the new task list. If the new task list eliminates the issue, then the cause can be attributed to the original task list or a change that was made to it. To change the task list that the workflow uses: In Workflow Designer select Settings -> Startup Options Then configure the task list as required If any of the scenarios above do not help, check the SharePoint logs for any messages with a category of ‘Workflow Infrastructure’. Conclusion The information in this article has been gathered from observations and investigations by Nintex. The sources of these issues are the underlying SharePoint workflow engine. This article will be updated if further causes are discovered. From <http://connect.nintex.com/forums/thread/6503.aspx>

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  • Scan a Windows PC for Viruses from a Ubuntu Live CD

    - by Trevor Bekolay
    Getting a virus is bad. Getting a virus that causes your computer to crash when you reboot is even worse. We’ll show you how to clean viruses from your computer even if you can’t boot into Windows by using a virus scanner in a Ubuntu Live CD. There are a number of virus scanners available for Ubuntu, but we’ve found that avast! is the best choice, with great detection rates and usability. Unfortunately, avast! does not have a proper 64-bit version, and forcing the install does not work properly. If you want to use avast! to scan for viruses, then ensure that you have a 32-bit Ubuntu Live CD. If you currently have a 64-bit Ubuntu Live CD on a bootable flash drive, it does not take long to wipe your flash drive and go through our guide again and select normal (32-bit) Ubuntu 9.10 instead of the x64 edition. For the purposes of fixing your Windows installation, the 64-bit Live CD will not provide any benefits. Once Ubuntu 9.10 boots up, open up Firefox by clicking on its icon in the top panel. Navigate to http://www.avast.com/linux-home-edition. Click on the Download tab, and then click on the link to download the DEB package. Save it to the default location. While avast! is downloading, click on the link to the registration form on the download page. Fill in the registration form if you do not already have a trial license for avast!. By the time you’ve filled out the registration form, avast! will hopefully be finished downloading. Open a terminal window by clicking on Applications in the top-left corner of the screen, then expanding the Accessories menu and clicking on Terminal. In the terminal window, type in the following commands, pressing enter after each line. cd Downloadssudo dpkg –i avast* This will install avast! on the live Ubuntu environment. To ensure that you can use the latest virus database, while still in the terminal window, type in the following command: sudo sysctl –w kernel.shmmax=128000000 Now we’re ready to open avast!. Click on Applications on the top-left corner of the screen, expand the Accessories folder, and click on the new avast! Antivirus item. You will first be greeted with a window that asks for your license key. Hopefully you’ve received it in your email by now; open the email that avast! sends you, copy the license key, and paste it in the Registration window. avast! Antivirus will open. You’ll notice that the virus database is outdated. Click on the Update database button and avast! will start downloading the latest virus database. To scan your Windows hard drive, you will need to “mount” it. While the virus database is downloading, click on Places on the top-left of your screen, and click on your Windows hard drive, if you can tell which one it is by its size. If you can’t tell which is the correct hard drive, then click on Computer and check out each hard drive until you find the right one. When you find it, make a note of the drive’s label, which appears in the menu bar of the file browser. Also note that your hard drive will now appear on your desktop. By now, your virus database should be updated. At the time this article was written, the most recent version was 100404-0. In the main avast! window, click on the radio button next to Selected folders and then click on the “+” button to the right of the list box. It will open up a dialog box to browse to a location. To find your Windows hard drive, click on the “>” next to the computer icon. In the expanded list, find the folder labelled “media” and click on the “>” next to it to expand it. In this list, you should be able to find the label that corresponds to your Windows hard drive. If you want to scan a certain folder, then you can go further into this hierarchy and select that folder. However, we will scan the entire hard drive, so we’ll just press OK. Click on Start scan and avast! will start scanning your hard drive. If a virus is found, you’ll be prompted to select an action. If you know that the file is a virus, then you can Delete it, but there is the possibility of false positives, so you can also choose Move to chest to quarantine it. When avast! is done scanning, it will summarize what it found on your hard drive. You can take different actions on those files at this time by right-clicking on them and selecting the appropriate action. When you’re done, click Close. Your Windows PC is now free of viruses, in the eyes of avast!. Reboot your computer and with any luck it will now boot up! Alternatives to avast! If avast! and a liberal amount of Googling doesn’t fix your problem, it’s possible that a different virus scanner will fix your obscure issue. Here are a list of other virus scanners available for Ubuntu that are either free or offer free trials. See their support forums for help on installing these virus scanners. Avira AntiVir Personal for Linux / Solaris Panda Antivirus for Linux Installation and usage guide from Ubuntu F-PROT Antivirus for Linux ClamAV installation and usage guide from Ubuntu NOD32 Antivirus for Linux Kaspersky Anti-Virus 2010 Bitdefender Antivirus for Unices Conclusion Running avast! from a Ubuntu Live CD can clean the vast majority of viruses from your Windows PC. This is another reason to always have a Ubuntu Live CD ready just in case something happens to your Windows installation! Similar Articles Productive Geek Tips Secure Computing: Windows Live OneCareHow To Remove Antivirus Live and Other Rogue/Fake Antivirus MalwareUse the Windows Key for the "Start" Menu in Ubuntu LinuxScan Files for Viruses Before You Download With Dr.WebAsk the Readers: Share Your Tips for Defeating Viruses and Malware TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 The Ultimate Guide For YouTube Lovers Will it Blend? iPad Edition Penolo Lets You Share Sketches On Twitter Visit Woolyss.com for Old School Games, Music and Videos Add a Custom Title in IE using Spybot or Spyware Blaster When You Need to Hail a Taxi in NYC

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  • HttpContext.Items and Server.Transfer/Execute

    - by Rick Strahl
    A few days ago my buddy Ben Jones pointed out that he ran into a bug in the ScriptContainer control in the West Wind Web and Ajax Toolkit. The problem was basically that when a Server.Transfer call was applied the script container (and also various ClientScriptProxy script embedding routines) would potentially fail to load up the specified scripts. It turns out the problem is due to the fact that the various components in the toolkit use request specific singletons via a Current property. I use a static Current property tied to a Context.Items[] entry to handle this type of operation which looks something like this: /// <summary> /// Current instance of this class which should always be used to /// access this object. There are no public constructors to /// ensure the reference is used as a Singleton to further /// ensure that all scripts are written to the same clientscript /// manager. /// </summary> public static ClientScriptProxy Current { get { if (HttpContext.Current == null) return new ClientScriptProxy(); ClientScriptProxy proxy = null; if (HttpContext.Current.Items.Contains(STR_CONTEXTID)) proxy = HttpContext.Current.Items[STR_CONTEXTID] as ClientScriptProxy; else { proxy = new ClientScriptProxy(); HttpContext.Current.Items[STR_CONTEXTID] = proxy; } return proxy; } } The proxy is attached to a Context.Items[] item which makes the instance Request specific. This works perfectly fine in most situations EXCEPT when you’re dealing with Server.Transfer/Execute requests. Server.Transfer doesn’t cause Context.Items to be cleared so both the current transferred request and the original request’s Context.Items collection apply. For the ClientScriptProxy this causes a problem because script references are tracked on a per request basis in Context.Items to check for script duplication. Once a script is rendered an ID is written into the Context collection and so considered ‘rendered’: // No dupes - ref script include only once if (HttpContext.Current.Items.Contains( STR_SCRIPTITEM_IDENTITIFIER + fileId ) ) return; HttpContext.Current.Items.Add(STR_SCRIPTITEM_IDENTITIFIER + fileId, string.Empty); where the fileId is the script name or unique identifier. The problem is on the Transferred page the item will already exist in Context and so fail to render because it thinks the script has already rendered based on the Context item. Bummer. The workaround for this is simple once you know what’s going on, but in this case it was a bitch to track down because the context items are used in many places throughout this class. The trick is to determine when a request is transferred and then removing the specific keys. The first issue is to determine if a script is in a Trransfer or Execute call: if (HttpContext.Current.CurrentHandler != HttpContext.Current.Handler) Context.Handler is the original handler and CurrentHandler is the actual currently executing handler that is running when a Transfer/Execute is active. You can also use Context.PreviousHandler to get the last handler and chain through the whole list of handlers applied if Transfer calls are nested (dog help us all for the person debugging that). For the ClientScriptProxy the full logic to check for a transfer and remove the code looks like this: /// <summary> /// Clears all the request specific context items which are script references /// and the script placement index. /// </summary> public void ClearContextItemsOnTransfer() { if (HttpContext.Current != null) { // Check for Server.Transfer/Execute calls - we need to clear out Context.Items if (HttpContext.Current.CurrentHandler != HttpContext.Current.Handler) { List<string> Keys = HttpContext.Current.Items.Keys.Cast<string>().Where(s => s.StartsWith(STR_SCRIPTITEM_IDENTITIFIER) || s == STR_ScriptResourceIndex).ToList(); foreach (string key in Keys) { HttpContext.Current.Items.Remove(key); } } } } along with a small update to the Current property getter that sets a global flag to indicate whether the request was transferred: if (!proxy.IsTransferred && HttpContext.Current.Handler != HttpContext.Current.CurrentHandler) { proxy.ClearContextItemsOnTransfer(); proxy.IsTransferred = true; } return proxy; I know this is pretty ugly, but it works and it’s actually minimal fuss without affecting the behavior of the rest of the class. Ben had a different solution that involved explicitly clearing out the Context items and replacing the collection with a manually maintained list of items which also works, but required changes through the code to make this work. In hindsight, it would have been better to use a single object that encapsulates all the ‘persisted’ values and store that object in Context instead of all these individual small morsels. Hindsight is always 20/20 though :-}. If possible use Page.Items ClientScriptProxy is a generic component that can be used from anywhere in ASP.NET, so there are various methods that are not Page specific on this component which is why I used Context.Items, rather than the Page.Items collection.Page.Items would be a better choice since it will sidestep the above Server.Transfer nightmares as the Page is reloaded completely and so any new Page gets a new Items collection. No fuss there. So for the ScriptContainer control, which has to live on the page the behavior is a little different. It is attached to Page.Items (since it’s a control): /// <summary> /// Returns a current instance of this control if an instance /// is already loaded on the page. Otherwise a new instance is /// created, added to the Form and returned. /// /// It's important this function is not called too early in the /// page cycle - it should not be called before Page.OnInit(). /// /// This property is the preferred way to get a reference to a /// ScriptContainer control that is either already on a page /// or needs to be created. Controls in particular should always /// use this property. /// </summary> public static ScriptContainer Current { get { // We need a context for this to work! if (HttpContext.Current == null) return null; Page page = HttpContext.Current.CurrentHandler as Page; if (page == null) throw new InvalidOperationException(Resources.ERROR_ScriptContainer_OnlyWorks_With_PageBasedHandlers); ScriptContainer ctl = null; // Retrieve the current instance ctl = page.Items[STR_CONTEXTID] as ScriptContainer; if (ctl != null) return ctl; ctl = new ScriptContainer(); page.Form.Controls.Add(ctl); return ctl; } } The biggest issue with this approach is that you have to explicitly retrieve the page in the static Current property. Notice again the use of CurrentHandler (rather than Handler which was my original implementation) to ensure you get the latest page including the one that Server.Transfer fired. Server.Transfer and Server.Execute are Evil All that said – this fix is probably for the 2 people who are crazy enough to rely on Server.Transfer/Execute. :-} There are so many weird behavior problems with these commands that I avoid them at all costs. I don’t think I have a single application that uses either of these commands… Related Resources Full source of ClientScriptProxy.cs (repository) Part of the West Wind Web Toolkit Static Singletons for ASP.NET Controls Post © Rick Strahl, West Wind Technologies, 2005-2010Posted in ASP.NET  

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  • Oracle Enterprise Manager 11g Application Management Suite for Oracle E-Business Suite Now Available

    - by chung.wu
    Oracle Enterprise Manager 11g Application Management Suite for Oracle E-Business Suite is now available. The management suite combines features that were available in the standalone Application Management Pack for Oracle E-Business Suite and Application Change Management Pack for Oracle E-Business Suite with Oracle's market leading real user monitoring and configuration management capabilities to provide the most complete solution for managing E-Business Suite applications. The features that were available in the standalone management packs are now packaged into Oracle E-Business Suite Plug-in 4.0, which is now fully certified with Oracle Enterprise Manager 11g Grid Control. This latest plug-in extends Grid Control with E-Business Suite specific management capabilities and features enhanced change management support. In addition, this latest release of Application Management Suite for Oracle E-Business Suite also includes numerous real user monitoring improvements. General Enhancements This new release of Application Management Suite for Oracle E-Business Suite offers the following key capabilities: Oracle Enterprise Manager 11g Grid Control Support: All components of the management suite are certified with Oracle Enterprise Manager 11g Grid Control. Built-in Diagnostic Ability: This release has numerous major enhancements that provide the necessary intelligence to determine if the product has been installed and configured correctly. There are diagnostics for Discovery, Cloning, and User Monitoring that will validate if the appropriate patches, privileges, setups, and profile options have been configured. This feature improves the setup and configuration time to be up and operational. Lifecycle Automation Enhancements Application Management Suite for Oracle E-Business Suite provides a centralized view to monitor and orchestrate changes (both functional and technical) across multiple Oracle E-Business Suite systems. In this latest release, it provides even more control and flexibility in managing Oracle E-Business Suite changes.Change Management: Built-in Diagnostic Ability: This latest release has numerous major enhancements that provide the necessary intelligence to determine if the product has been installed and configured correctly. There are diagnostics for Customization Manager, Patch Manager, and Setup Manager that will validate if the appropriate patches, privileges, setups, and profile options have been configured. Enhancing the setup time and configuration time to be up and operational. Customization Manager: Multi-Node Custom Application Registration: This feature automates the process of registering and validating custom products/applications on every node in a multi-node EBS system. Public/Private File Source Mappings and E-Business Suite Mappings: File Source Mappings & E-Business Suite Mappings can be created and marked as public or private. Only the creator/owner can define/edit his/her own mappings. Users can use public mappings, but cannot edit or change settings. Test Checkout Command for Versions: This feature allows you to test/verify checkout commands at the version level within the File Source Mapping page. Prerequisite Patch Validation: You can specify prerequisite patches for Customization packages and for Release 12 Oracle E-Business Suite packages. Destination Path Population: You can now automatically populate the Destination Path for common file types during package construction. OAF File Type Support: Ability to package Oracle Application Framework (OAF) customizations and deploy them across multiple Oracle E-Business Suite instances. Extended PLL Support: Ability to distinguish between different types of PLLs (that is, Report and Forms PLL files). Providing better granularity when managing PLL objects. Enhanced Standard Checker: Provides greater and more comprehensive list of coding standards that are verified during the package build process (for example, File Driver exceptions, Java checks, XML checks, SQL checks, etc.) HTML Package Readme: The package Readme is in HTML format and includes the file listing. Advanced Package Search Capabilities: The ability to utilize more criteria within the advanced search package (that is, Public, Last Updated by, Files Source Mapping, and E-Business Suite Mapping). Enhanced Package Build Notifications: More detailed information on the results of a package build process. Better, more detailed troubleshooting guidance in the event of build failures. Patch Manager:Staged Patches: Ability to run Patch Manager with no external internet access. Customer can download Oracle E-Business Suite patches into a shared location for Patch Manager to access and apply. Supports highly secured production environments that prohibit external internet connections. Support for Superseded Patches: Automatic check for superseded patches. Allows users to easily add superseded patches into the Patch Run. More comprehensive and correct Patch Runs. Removes many manual and laborious tasks, frees up Apps DBAs for higher value-added tasks. Automatic Primary Node Identification: Users can now specify which is the "primary node" (that is, which node hosts the Shared APPL_TOP) during the Patch Run interview process, available for Release 12 only. Setup Manager:Preview Extract Results: Ability to execute an extract in "proof mode", and examine the query results, to determine accuracy. Used in conjunction with the "where" clause in Advanced Filtering. This feature can provide better and more accurate fine tuning of extracts. Use Uploaded Extracts in New Projects: Ability to incorporate uploaded extracts in new projects via new LOV fields in package construction. Leverages the Setup Manager repository to access extracts that have been uploaded. Allows customer to reuse uploaded extracts to provision new instances. Re-use Existing (that is, historical) Extracts in New Projects: Ability to incorporate existing extracts in new projects via new LOV fields in package construction. Leverages the Setup Manager repository to access point-in-time extracts (snapshots) of configuration data. Allows customer to reuse existing extracts to provision new instances. Allows comparative historical reporting of identical APIs, executed at different times. Support for BR100 formats: Setup Manager can now automatically produce reports in the BR100 format. Native support for industry standard formats. Concurrent Manager API Support: General Foundation now provides an API for management of "Concurrent Manager" configuration data. Ability to migrate Concurrent Managers from one instance to another. Complete the setup once and never again; no need to redefine the Concurrent Managers. User Experience Management Enhancements Application Management Suite for Oracle E-Business Suite includes comprehensive capabilities for user experience management, supporting both real user and synthetic transaction based user monitoring techniques. This latest release of the management suite include numerous improvements in real user monitoring support. KPI Reporting: Configurable decimal precision for reporting of KPI and SLA values. By default, this is two decimal places. KPI numerator and denominator information. It is now possible to view KPI numerator and denominator information, and to have it available for export. Content Messages Processing: The application content message facility has been extended to distinguish between notifications and errors. In addition, it is now possible to specify matching rules that can be used to refine a selected content message specification. Note this is only available for XPath-based (not literal) message contents. Data Export: The Enriched data export facility has been significantly enhanced to provide improved performance and accessibility. Data is no longer stored within XML-based files, but is now stored within the Reporter database. However, it is possible to configure an alternative database for its storage. Access to the export data is through SQL. With this enhancement, it is now more easy than ever to use tools such as Oracle Business Intelligence Enterprise Edition to analyze correlated data collected from real user monitoring and business data sources. SNMP Traps for System Events: Previously, the SNMP notification facility was only available for KPI alerting. It has now been extended to support the generation of SNMP traps for system events, to provide external health monitoring of the RUEI system processes. Performance Improvements: Enhanced dashboard performance. The dashboard facility has been enhanced to support the parallel loading of items. In the case of dashboards containing large numbers of items, this can result in a significant performance improvement. Initial period selection within Data Browser and reports. The User Preferences facility has been extended to allow you to specify the initial period selection when first entering the Data Browser or reports facility. The default is the last hour. Performance improvement when querying the all sessions group. Technical Prerequisites, Download and Installation Instructions The Linux version of the plug-in is available for immediate download from Oracle Technology Network or Oracle eDelivery. For specific information regarding technical prerequisites, product download and installation, please refer to My Oracle Support note 1224313.1. The following certifications are in progress: * Oracle Solaris on SPARC (64-bit) (9, 10) * HP-UX Itanium (11.23, 11.31) * HP-UX PA-RISC (64-bit) (11.23, 11.31) * IBM AIX on Power Systems (64-bit) (5.3, 6.1)

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  • DropDownList and SelectListItem Array Item Updates in MVC

    - by Rick Strahl
    So I ran into an interesting behavior today as I deployed my first MVC 4 app tonight. I have a list form that has a filter drop down that allows selection of categories. This list is static and rarely changes so rather than loading these items from the database each time I load the items once and then cache the actual SelectListItem[] array in a static property. However, when we put the site online tonight we immediately noticed that the drop down list was coming up with pre-set values that randomly changed. Didn't take me long to trace this back to the cached list of SelectListItem[]. Clearly the list was getting updated - apparently through the model binding process in the selection postback. To clarify the scenario here's the drop down list definition in the Razor View:@Html.DropDownListFor(mod => mod.QueryParameters.Category, Model.CategoryList, "All Categories") where Model.CategoryList gets set with:[HttpPost] [CompressContent] public ActionResult List(MessageListViewModel model) { InitializeViewModel(model); busEntry entryBus = new busEntry(); var entries = entryBus.GetEntryList(model.QueryParameters); model.Entries = entries; model.DisplayMode = ApplicationDisplayModes.Standard; model.CategoryList = AppUtils.GetCachedCategoryList(); return View(model); } The AppUtils.GetCachedCategoryList() method gets the cached list or loads the list on the first access. The code to load up the list is housed in a Web utility class. The method looks like this:/// <summary> /// Returns a static category list that is cached /// </summary> /// <returns></returns> public static SelectListItem[] GetCachedCategoryList() { if (_CategoryList != null) return _CategoryList; lock (_SyncLock) { if (_CategoryList != null) return _CategoryList; var catBus = new busCategory(); var categories = catBus.GetCategories().ToList(); // Turn list into a SelectItem list var catList= categories .Select(cat => new SelectListItem() { Text = cat.Name, Value = cat.Id.ToString() }) .ToList(); catList.Insert(0, new SelectListItem() { Value = ((int)SpecialCategories.AllCategoriesButRealEstate).ToString(), Text = "All Categories except Real Estate" }); catList.Insert(1, new SelectListItem() { Value = "-1", Text = "--------------------------------" }); _CategoryList = catList.ToArray(); } return _CategoryList; } private static SelectListItem[] _CategoryList ; This seemed normal enough to me - I've been doing stuff like this forever caching smallish lists in memory to avoid an extra trip to the database. This list is used in various places throughout the application - for the list display and also when adding new items and setting up for notifications etc.. Watch that ModelBinder! However, it turns out that this code is clearly causing a problem. It appears that the model binder on the [HttpPost] method is actually updating the list that's bound to and changing the actual entry item in the list and setting its selected value. If you look at the code above I'm not setting the SelectListItem.Selected value anywhere - the only place this value can get set is through ModelBinding. Sure enough when stepping through the code I see that when an item is selected the actual model - model.CategoryList[x].Selected - reflects that. This is bad on several levels: First it's obviously affecting the application behavior - nobody wants to see their drop down list values jump all over the place randomly. But it's also a problem because the array is getting updated by multiple ASP.NET threads which likely would lead to odd crashes from time to time. Not good! In retrospect the modelbinding behavior makes perfect sense. The actual items and the Selected property is the ModelBinder's way of keeping track of one or more selected values. So while I assumed the list to be read-only, the ModelBinder is actually updating it on a post back producing the rather surprising results. Totally missed this during testing and is another one of those little - "Did you know?" moments. So, is there a way around this? Yes but it's maybe not quite obvious. I can't change the behavior of the ModelBinder, but I can certainly change the way that the list is generated. Rather than returning the cached list, I can return a brand new cloned list from the cached items like this:/// <summary> /// Returns a static category list that is cached /// </summary> /// <returns></returns> public static SelectListItem[] GetCachedCategoryList() { if (_CategoryList != null) { // Have to create new instances via projection // to avoid ModelBinding updates to affect this // globally return _CategoryList .Select(cat => new SelectListItem() { Value = cat.Value, Text = cat.Text }) .ToArray(); } …}  The key is that newly created instances of SelectListItems are returned not just filtered instances of the original list. The key here is 'new instances' so that the ModelBinding updates do not update the actual static instance. The code above uses LINQ and a projection into new SelectListItem instances to create this array of fresh instances. And this code works correctly - no more cross-talk between users. Unfortunately this code is also less efficient - it has to reselect the items and uses extra memory for the new array. Knowing what I know now I probably would have not cached the list and just take the hit to read from the database. If there is even a possibility of thread clashes I'm very wary of creating code like this. But since the method already exists and handles this load in one place this fix was easy enough to put in. Live and learn. It's little things like this that can cause some interesting head scratchers sometimes…© Rick Strahl, West Wind Technologies, 2005-2012Posted in MVC  ASP.NET  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Adding DTrace Probes to PHP Extensions

    - by cj
    The powerful DTrace tracing facility has some PHP-specific probes that can be enabled with --enable-dtrace. DTrace for Linux is being created by Oracle and is currently in tech preview. Currently it doesn't support userspace tracing so, in the meantime, Systemtap can be used to monitor the probes implemented in PHP. This was recently outlined in David Soria Parra's post Probing PHP with Systemtap on Linux. My post shows how DTrace probes can be added to PHP extensions and traced on Linux. I was using Oracle Linux 6.3. Not all Linux kernels are built with Systemtap, since this can impact stability. Check whether your running kernel (or others installed) have Systemtap enabled, and reboot with such a kernel: # grep CONFIG_UTRACE /boot/config-`uname -r` # grep CONFIG_UTRACE /boot/config-* When you install Systemtap itself, the package systemtap-sdt-devel is needed since it provides the sdt.h header file: # yum install systemtap-sdt-devel You can now install and build PHP as shown in David's article. Basically the build is with: $ cd ~/php-src $ ./configure --disable-all --enable-dtrace $ make (For me, running 'make' a second time failed with an error. The workaround is to do 'git checkout Zend/zend_dtrace.d' and then rerun 'make'. See PHP Bug 63704) David's article shows how to trace the probes already implemented in PHP. You can also use Systemtap to trace things like userspace PHP function calls. For example, create test.php: <?php $c = oci_connect('hr', 'welcome', 'localhost/orcl'); $s = oci_parse($c, "select dbms_xmlgen.getxml('select * from dual') xml from dual"); $r = oci_execute($s); $row = oci_fetch_array($s, OCI_NUM); $x = $row[0]->load(); $row[0]->free(); echo $x; ?> The normal output of this file is the XML form of Oracle's DUAL table: $ ./sapi/cli/php ~/test.php <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> To trace the PHP function calls, create the tracing file functrace.stp: probe process("sapi/cli/php").function("zif_*") { printf("Started function %s\n", probefunc()); } probe process("sapi/cli/php").function("zif_*").return { printf("Ended function %s\n", probefunc()); } This makes use of the way PHP userspace functions (not builtins) like oci_connect() map to C functions with a "zif_" prefix. Login as root, and run System tap on the PHP script: # cd ~cjones/php-src # stap -c 'sapi/cli/php ~cjones/test.php' ~cjones/functrace.stp Started function zif_oci_connect Ended function zif_oci_connect Started function zif_oci_parse Ended function zif_oci_parse Started function zif_oci_execute Ended function zif_oci_execute Started function zif_oci_fetch_array Ended function zif_oci_fetch_array Started function zif_oci_lob_load <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> Ended function zif_oci_lob_load Started function zif_oci_free_descriptor Ended function zif_oci_free_descriptor Each call and return is logged. The Systemtap scripting language allows complex scripts to be built. There are many examples on the web. To augment this generic capability and the PHP probes in PHP, other extensions can have probes too. Below are the steps I used to add probes to OCI8: I created a provider file ext/oci8/oci8_dtrace.d, enabling three probes. The first one will accept a parameter that runtime tracing can later display: provider php { probe oci8__connect(char *username); probe oci8__nls_start(); probe oci8__nls_done(); }; I updated ext/oci8/config.m4 with the PHP_INIT_DTRACE macro. The patch is at the end of config.m4. The macro takes the provider prototype file, a name of the header file that 'dtrace' will generate, and a list of sources files with probes. When --enable-dtrace is used during PHP configuration, then the outer $PHP_DTRACE check is true and my new probes will be enabled. I've chosen to define an OCI8 specific macro, HAVE_OCI8_DTRACE, which can be used in the OCI8 source code: diff --git a/ext/oci8/config.m4 b/ext/oci8/config.m4 index 34ae76c..f3e583d 100644 --- a/ext/oci8/config.m4 +++ b/ext/oci8/config.m4 @@ -341,4 +341,17 @@ if test "$PHP_OCI8" != "no"; then PHP_SUBST_OLD(OCI8_ORACLE_VERSION) fi + + if test "$PHP_DTRACE" = "yes"; then + AC_CHECK_HEADERS([sys/sdt.h], [ + PHP_INIT_DTRACE([ext/oci8/oci8_dtrace.d], + [ext/oci8/oci8_dtrace_gen.h],[ext/oci8/oci8.c]) + AC_DEFINE(HAVE_OCI8_DTRACE,1, + [Whether to enable DTrace support for OCI8 ]) + ], [ + AC_MSG_ERROR( + [Cannot find sys/sdt.h which is required for DTrace support]) + ]) + fi + fi In ext/oci8/oci8.c, I added the probes at, for this example, semi-arbitrary places: diff --git a/ext/oci8/oci8.c b/ext/oci8/oci8.c index e2241cf..ffa0168 100644 --- a/ext/oci8/oci8.c +++ b/ext/oci8/oci8.c @@ -1811,6 +1811,12 @@ php_oci_connection *php_oci_do_connect_ex(char *username, int username_len, char } } +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_CONNECT_ENABLED()) { + DTRACE_OCI8_CONNECT(username); + } +#endif + /* Initialize global handles if they weren't initialized before */ if (OCI_G(env) == NULL) { php_oci_init_global_handles(TSRMLS_C); @@ -1870,11 +1876,22 @@ php_oci_connection *php_oci_do_connect_ex(char *username, int username_len, char size_t rsize = 0; sword result; +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_NLS_START_ENABLED()) { + DTRACE_OCI8_NLS_START(); + } +#endif PHP_OCI_CALL_RETURN(result, OCINlsEnvironmentVariableGet, (&charsetid_nls_lang, 0, OCI_NLS_CHARSET_ID, 0, &rsize)); if (result != OCI_SUCCESS) { charsetid_nls_lang = 0; } smart_str_append_unsigned_ex(&hashed_details, charsetid_nls_lang, 0); + +#ifdef HAVE_OCI8_DTRACE + if (DTRACE_OCI8_NLS_DONE_ENABLED()) { + DTRACE_OCI8_NLS_DONE(); + } +#endif } timestamp = time(NULL); The oci_connect(), oci_pconnect() and oci_new_connect() calls all use php_oci_do_connect_ex() internally. The first probe simply records that the PHP application made a connection call. I already showed a way to do this without needing a probe, but adding a specific probe lets me record the username. The other two probes can be used to time how long the globalization initialization takes. The relationships between the oci8_dtrace.d names like oci8__connect, the probe guards like DTRACE_OCI8_CONNECT_ENABLED() and probe names like DTRACE_OCI8_CONNECT() are obvious after seeing the pattern of all three probes. I included the new header that will be automatically created by the dtrace tool when PHP is built. I did this in ext/oci8/php_oci8_int.h: diff --git a/ext/oci8/php_oci8_int.h b/ext/oci8/php_oci8_int.h index b0d6516..c81fc5a 100644 --- a/ext/oci8/php_oci8_int.h +++ b/ext/oci8/php_oci8_int.h @@ -44,6 +44,10 @@ # endif # endif /* osf alpha */ +#ifdef HAVE_OCI8_DTRACE +#include "oci8_dtrace_gen.h" +#endif + #if defined(min) #undef min #endif Now PHP can be rebuilt: $ cd ~/php-src $ rm configure && ./buildconf --force $ ./configure --disable-all --enable-dtrace \ --with-oci8=instantclient,/home/cjones/instantclient $ make If 'make' fails, do the 'git checkout Zend/zend_dtrace.d' trick I mentioned. The new probes can be seen by logging in as root and running: # stap -l 'process.provider("php").mark("oci8*")' -c 'sapi/cli/php -i' process("sapi/cli/php").provider("php").mark("oci8__connect") process("sapi/cli/php").provider("php").mark("oci8__nls_done") process("sapi/cli/php").provider("php").mark("oci8__nls_start") To test them out, create a new trace file, oci.stp: global numconnects; global start; global numcharlookups = 0; global tottime = 0; probe process.provider("php").mark("oci8-connect") { printf("Connected as %s\n", user_string($arg1)); numconnects += 1; } probe process.provider("php").mark("oci8-nls_start") { start = gettimeofday_us(); numcharlookups++; } probe process.provider("php").mark("oci8-nls_done") { tottime += gettimeofday_us() - start; } probe end { printf("Connects: %d, Charset lookups: %ld\n", numconnects, numcharlookups); printf("Total NLS charset initalization time: %ld usecs/connect\n", (numcharlookups 0 ? tottime/numcharlookups : 0)); } This calculates the average time that the NLS character set lookup takes. It also prints out the username of each connection, as an example of using parameters. Login as root and run Systemtap over the PHP script: # cd ~cjones/php-src # stap -c 'sapi/cli/php ~cjones/test.php' ~cjones/oci.stp Connected as cj <?xml version="1.0"?> <ROWSET> <ROW> <DUMMY>X</DUMMY> </ROW> </ROWSET> Connects: 1, Charset lookups: 1 Total NLS charset initalization time: 164 usecs/connect This shows the time penalty of making OCI8 look up the default character set. This time would be zero if a character set had been passed as the fourth argument to oci_connect() in test.php.

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  • Simplify your Ajax code by using jQuery Global Ajax Handlers and ajaxSetup low-level interface

    - by hajan
    Creating web applications with consistent layout and user interface is very important for your users. In several ASP.NET projects I’ve completed lately, I’ve been using a lot jQuery and jQuery Ajax to achieve rich user experience and seamless interaction between the client and the server. In almost all of them, I took advantage of the nice jQuery global ajax handlers and jQuery ajax functions. Let’s say you build web application which mainly interacts using Ajax post and get to accomplish various operations. As you may already know, you can easily perform Ajax operations using jQuery Ajax low-level method or jQuery $.get, $.post, etc. Simple get example: $.get("/Home/GetData", function (d) { alert(d); }); As you can see, this is the simplest possible way to make Ajax call. What it does in behind is constructing low-level Ajax call by specifying all necessary information for the request, filling with default information set for the required properties such as data type, content type, etc... If you want to have some more control over what is happening with your Ajax Request, you can easily take advantage of the global ajax handlers. In order to register global ajax handlers, jQuery API provides you set of global Ajax methods. You can find all the methods in the following link http://api.jquery.com/category/ajax/global-ajax-event-handlers/, and these are: ajaxComplete ajaxError ajaxSend ajaxStart ajaxStop ajaxSuccess And the low-level ajax interfaces http://api.jquery.com/category/ajax/low-level-interface/: ajax ajaxPrefilter ajaxSetup For global settings, I usually use ajaxSetup combining it with the ajax event handlers. $.ajaxSetup is very good to help you set default values that you will use in all of your future Ajax Requests, so that you won’t need to repeat the same properties all the time unless you want to override the default settings. Mainly, I am using global ajaxSetup function similarly to the following way: $.ajaxSetup({ cache: false, error: function (x, e) { if (x.status == 550) alert("550 Error Message"); else if (x.status == "403") alert("403. Not Authorized"); else if (x.status == "500") alert("500. Internal Server Error"); else alert("Error..."); }, success: function (x) { //do something global on success... } }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Now, you can make ajax call using low-level $.ajax interface and you don’t need to worry about specifying any of the properties we’ve set in the $.ajaxSetup function. So, you can create your own ways to handle various situations when your Ajax requests are occurring. Sometimes, some of your Ajax Requests may take much longer than expected… So, in order to make user friendly UI that will show some progress bar or animated image that something is happening in behind, you can combine ajaxStart and ajaxStop methods to do the same. First of all, add one <div id=”loading” style=”display:none;”> <img src="@Url.Content("~/Content/images/ajax-loader.gif")" alt="Ajax Loader" /></div> anywhere on your Master Layout / Master page (you can download nice ajax loading images from http://ajaxload.info/). Then, add the following two handlers: $(document).ajaxStart(function () { $("#loading").attr("style", "position:absolute; z-index: 1000; top: 0px; "+ "left:0px; text-align: center; display:none; background-color: #ddd; "+ "height: 100%; width: 100%; /* These three lines are for transparency "+ "in all browsers. */-ms-filter:\"progid:DXImageTransform.Microsoft.Alpha(Opacity=50)\";"+ " filter: alpha(opacity=50); opacity:.5;"); $("#loading img").attr("style", "position:relative; top:40%; z-index:5;"); $("#loading").show(); }); $(document).ajaxStop(function () { $("#loading").removeAttr("style"); $("#loading img").removeAttr("style"); $("#loading").hide(); }); .csharpcode, .csharpcode pre { font-size: small; color: black; font-family: consolas, "Courier New", courier, monospace; background-color: #ffffff; /*white-space: pre;*/ } .csharpcode pre { margin: 0em; } .csharpcode .rem { color: #008000; } .csharpcode .kwrd { color: #0000ff; } .csharpcode .str { color: #006080; } .csharpcode .op { color: #0000c0; } .csharpcode .preproc { color: #cc6633; } .csharpcode .asp { background-color: #ffff00; } .csharpcode .html { color: #800000; } .csharpcode .attr { color: #ff0000; } .csharpcode .alt { background-color: #f4f4f4; width: 100%; margin: 0em; } .csharpcode .lnum { color: #606060; } Note: While you can reorganize the style in a more reusable way, since these are global Ajax Start/Stop, it is very possible that you won’t use the same style in other places. With this way, you will see that now for any ajax request in your web site or application, you will have the loading image appearing providing better user experience. What I’ve shown is several useful examples on how to simplify your Ajax code by using Global Ajax Handlers and the low-level AjaxSetup function. Of course, you can do a lot more with the other methods as well. Hope this was helpful. Regards, Hajan

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  • Getting Started with Media Browser for Windows Media Center

    - by DigitalGeekery
    If you are a Windows Media Center user, you’ll really want to check out Media Browser. The Media Browser plug-in for Windows Media Center takes your digital media files and displays them in a visually appealing, user friendly interface, complete with images and metadata. Requirements Windows 7 or Vista Microsoft .Net 3.5 Framework  Preparing your Media Files For Media Browser to be able to automatically download images and metadata for your media libraries, your files will have to be correctly named. For example, if you have an mp4 file of the movie Batman Begins, it needs to be named Batman Begins.mp4. It cannot be Batmanbegins.mp4 or Batman-begins.mp4. Otherwise, it’s unlikely that Media Browser will display images and metadata. If you find some of your files aren’t pulling cover art or metadata, double-check the official title of the media on a site like IMBD.com. TV Show files TV show files are handled a bit differently. Every TV series in your collection must have a main folder with the show’s name and individual subfolders for each season. Here is an example of folder structure and supported naming conventions. TV Shows\South Park\Season 1\s01e01 – episode 1.mp4 TV Shows\South Park\Season 1\South Park 1×01 – episode 1.mp4 TV Shows\South Park\Season 1\101 – episode 1.mp4  Note: You need to always have a Season 1 folder even if the show only has only one season. If you have several seasons of a particular show, but don’t happen to have Season 1, simply create a blank season 1 folder. Without a season 1 folder, other seasons will not display properly. Installation and Configuration Download and run the latest Media Browser .msi file by taking the defaults. (Download link below) When you reach the final window, leave the “Configure initial settings” box checked, and click “Finish.” You may get a pop up window informing you that folder permissions are not set correctly for Media Browser. Click “Yes.” Adding Your Media The Browser Configuration Tool should have opened automatically. If not, you can open it by going to Start > All Programs > Media Browser > Media Browser Configuration Wizard. To begin adding media files, click “Add.” Browse for a folder that contains media files and click “OK.” Here we are adding a folder with a group of movie files. You can add multiple folders to each media library. For example, if you have movie files stored in 4 or 5 different folders, you can add them all under a single library in Media Browser.  To add additional folders, click the “Add” button on the right side under your currently added folder. The “Add” button to the left will add an additional Media Library, such as one for TV Shows. When you are finished, close out of the Media Browser Configuration Tool. Open Windows Media Center. You will see Media Browser tile on the main interface. Click to open it. When you initially open Media Browser, you will be prompted to run the initial configuration. Click “OK.” You will see a few general configuration options. The important option is the Metadata. Leave this option checked (it is by default) if you wish to pull images & other metadata for your media. When finished, click “Continue,” and then “OK” to restart Media Browser. When you re-enter Media Browser you’ll see your Media Categories listed below, and recently added files in the main display. Click on a Media Library to view the files.   Click “View” at the top to check out some of the different display options to choose from. Below you see can “Detail.” This presents your videos in a list to the left. When you hover over a title, the synopsis and cover art is displayed to the right. “Cover Flow” displays your titles in a right to left format with mirror cover art. “Thumb Strip” displays your titles in a strip along the bottom with a synopsis, image, and movie data above. Configurations Settings and options can be changed through the Media Browser Configuration Tool, or directly in Media Browser by clicking on the “Wrench” at the bottom right of the main Media Browser page. Certain settings may only be available in one location or the other. Some will be available in both places.   Plug-ins and Themes Media Browser features a variety of Plug-ins and Themes that can add optional customization and slick visual appeal. To install plug-ins or themes, open the Media Browser Configuration Tool. Click on the “plug-ins” tab, and then the “More Plug-ins…” button. Note: Clicking on “Advanced” at the top will reveal several additional configuration tabs. Browse the list of plug-ins on the left. When you find want you like, select it and then click “Install.” When the install is complete, you’ll see them listed under “Installed Plug-ins.” To activate any installed theme, click on the “Display” tab. Select it from the Visual Theme drop down list. Close out of the Media Browser Configuration Tool when finished. Some themes, such as the “Diamond” theme shown below, include optional views and settings which can be accessed through a configuration button at the top of the screen. Clicking on the movie gives you additional images and information such as a synopsis, runtime, IMDB rating…   … and even actors and character names.   All that’s left is to hit “Play” when you’re ready to watch.   Conclusion Media Browser is a fantastic plug-in that brings an entirely different level of media management and aesthetics to Windows Media Center. There are numerous additional customizations and configurations we have not covered here such as adding film trailers, music support, and integrating Recorded TV. Media Browser will run on both Windows 7 and Vista. Extenders are also supported but may require additional configuration. Download Media Browser Similar Articles Productive Geek Tips Using Netflix Watchnow in Windows Vista Media Center (Gmedia)Schedule Updates for Windows Media CenterIntegrate Hulu Desktop and Windows Media Center in Windows 7Add Color Coding to Windows 7 Media Center Program GuideIntegrate Boxee with Media Center in Windows 7 TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 If it were only this easy SyncToy syncs Files and Folders across Computers on a Network (or partitions on the same drive) Classic Cinema Online offers 100’s of OnDemand Movies OutSync will Sync Photos of your Friends on Facebook and Outlook Windows 7 Easter Theme YoWindoW, a real time weather screensaver

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  • Wishful Thinking: Why can't HTML fix Script Attacks at the Source?

    - by Rick Strahl
    The Web can be an evil place, especially if you're a Web Developer blissfully unaware of Cross Site Script Attacks (XSS). Even if you are aware of XSS in all of its insidious forms, it's extremely complex to deal with all the issues if you're taking user input and you're actually allowing users to post raw HTML into an application. I'm dealing with this again today in a Web application where legacy data contains raw HTML that has to be displayed and users ask for the ability to use raw HTML as input for listings. The first line of defense of course is: Just say no to HTML input from users. If you don't allow HTML input directly and use HTML Encoding (HttyUtility.HtmlEncode() in .NET or using standard ASP.NET MVC output @Model.Content) you're fairly safe at least from the HTML input provided. Both WebForms and Razor support HtmlEncoded content, although Razor makes it the default. In Razor the default @ expression syntax:@Model.UserContent automatically produces HTML encoded content - you actually have to go out of your way to create raw HTML content (safe by default) using @Html.Raw() or the HtmlString class. In Web Forms (V4) you can use:<%: Model.UserContent %> or if you're using a version prior to 4.0:<%= HttpUtility.HtmlEncode(Model.UserContent) %> This works great as a hedge against embedded <script> tags and HTML markup as any HTML is turned into text that displays as HTML but doesn't render the HTML. But it turns any embedded HTML markup tags into plain text. If you need to display HTML in raw form with the markup tags rendering based on user input this approach is worthless. If you do accept HTML input and need to echo the rendered HTML input back, the task of cleaning up that HTML is a complex task. In the projects I work on, customers are frequently asking for the ability to post raw HTML quite frequently.  Almost every app that I've built where there's document content from users we start out with text only input - possibly using something like MarkDown - but inevitably users want to just post plain old HTML they created in some other rich editing application. See this a lot with realtors especially who often want to reuse their postings easily in multiple places. In my work this is a common problem I need to deal with and I've tried dozens of different methods from sanitizing, simple rejection of input to custom markup schemes none of which have ever felt comfortable to me. They work in a half assed, hacked together sort of way but I always live in fear of missing something vital which is *really easy to do*. My Wishlist Item: A <restricted> tag in HTML Let me dream here for a second on how to address this problem. It seems to me the easiest place where this can be fixed is: In the browser. Browsers are actually executing script code so they have a lot of control over the script code that resides in a page. What if there was a way to specify that you want to turn off script code for a block of HTML? The main issue when dealing with HTML raw input isn't that we as developers are unaware of the implications of user input, but the fact that we sometimes have to display raw HTML input the user provides. So the problem markup is usually isolated in only a very specific part of the document. So, what if we had a way to specify that in any given HTML block, no script code could execute by wrapping it into a tag that disables all script functionality in the browser? This would include <script> tags and any document script attributes like onclick, onfocus etc. and potentially also disallow things like iFrames that can potentially be scripted from the within the iFrame's target. I'd like to see something along these lines:<article> <restricted allowscripts="no" allowiframes="no"> <div>Some content</div> <script>alert('go ahead make my day, punk!");</script> <div onfocus="$.getJson('http://evilsite.com/')">more content</div> </restricted> </article> A tag like this would basically disallow all script code from firing from any HTML that's rendered within it. You'd use this only on code that you actually render from your data only and only if you are dealing with custom data. So something like this:<article> <restricted> @Html.Raw(Model.UserContent) </restricted> </article> For browsers this would actually be easy to intercept. They render the DOM and control loading and execution of scripts that are loaded through it. All the browser would have to do is suspend execution of <script> tags and not hookup any event handlers defined via markup in this block. Given all the crazy XSS attacks that exist and the prevalence of this problem this would go a long way towards preventing at least coded script attacks in the DOM. And it seems like a totally doable solution that wouldn't be very difficult to implement by vendors. There would also need to be some logic in the parser to not allow an </restricted> or <restricted> tag into the content as to short-circuit the rstricted section (per James Hart's comment). I'm sure there are other issues to consider as well that I didn't think of in my off-the-back-of-a-napkin concept here but the idea overall seems worth consideration I think. Without code running in a user supplied HTML block it'd be pretty hard to compromise a local HTML document and pass information like Cookies to a server. Or even send data to a server period. Short of an iFrame that can access the parent frame (which is another restriction that should be available on this <restricted> tag) that could potentially communicate back, there's not a lot a malicious site could do. The HTML could still 'phone home' via image links and href links potentially and basically say this site was accessed, but without the ability to run script code it would be pretty tough to pass along critical information to the server beyond that. Ahhhh… one can dream… Not holding my breath of course. The design by committee that is the W3C can't agree on anything in timeframes measured less than decades, but maybe this is one place where browser vendors can actually step up the pressure. This is something in their best interest to reduce the attack surface for vulnerabilities on their browser platforms significantly. Several people commented on Twitter today that there isn't enough discussion on issues like this that address serious needs in the web browser space. Realistically security has to be a number one concern with Web applications in general - there isn't a Web app out there that is not vulnerable. And yet nothing has been done to address these security issues even though there might be relatively easy solutions to make this happen. It'll take time, and it's probably not going to happen in our lifetime, but maybe this rambling thought sparks some ideas on how this sort of restriction can get into browsers in some way in the future.© Rick Strahl, West Wind Technologies, 2005-2012Posted in ASP.NET  HTML5  HTML  Security   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Dynamic Types and DynamicObject References in C#

    - by Rick Strahl
    I've been working a bit with C# custom dynamic types for several customers recently and I've seen some confusion in understanding how dynamic types are referenced. This discussion specifically centers around types that implement IDynamicMetaObjectProvider or subclass from DynamicObject as opposed to arbitrary type casts of standard .NET types. IDynamicMetaObjectProvider types  are treated special when they are cast to the dynamic type. Assume for a second that I've created my own implementation of a custom dynamic type called DynamicFoo which is about as simple of a dynamic class that I can think of:public class DynamicFoo : DynamicObject { Dictionary<string, object> properties = new Dictionary<string, object>(); public string Bar { get; set; } public DateTime Entered { get; set; } public override bool TryGetMember(GetMemberBinder binder, out object result) { result = null; if (!properties.ContainsKey(binder.Name)) return false; result = properties[binder.Name]; return true; } public override bool TrySetMember(SetMemberBinder binder, object value) { properties[binder.Name] = value; return true; } } This class has an internal dictionary member and I'm exposing this dictionary member through a dynamic by implementing DynamicObject. This implementation exposes the properties dictionary so the dictionary keys can be referenced like properties (foo.NewProperty = "Cool!"). I override TryGetMember() and TrySetMember() which are fired at runtime every time you access a 'property' on a dynamic instance of this DynamicFoo type. Strong Typing and Dynamic Casting I now can instantiate and use DynamicFoo in a couple of different ways: Strong TypingDynamicFoo fooExplicit = new DynamicFoo(); var fooVar = new DynamicFoo(); These two commands are essentially identical and use strong typing. The compiler generates identical code for both of them. The var statement is merely a compiler directive to infer the type of fooVar at compile time and so the type of fooExplicit is DynamicFoo, just like fooExplicit. This is very static - nothing dynamic about it - and it completely ignores the IDynamicMetaObjectProvider implementation of my class above as it's never used. Using either of these I can access the native properties:DynamicFoo fooExplicit = new DynamicFoo();// static typing assignmentsfooVar.Bar = "Barred!"; fooExplicit.Entered = DateTime.Now; // echo back static values Console.WriteLine(fooVar.Bar); Console.WriteLine(fooExplicit.Entered); but I have no access whatsoever to the properties dictionary. Basically this creates a strongly typed instance of the type with access only to the strongly typed interface. You get no dynamic behavior at all. The IDynamicMetaObjectProvider features don't kick in until you cast the type to dynamic. If I try to access a non-existing property on fooExplicit I get a compilation error that tells me that the property doesn't exist. Again, it's clearly and utterly non-dynamic. Dynamicdynamic fooDynamic = new DynamicFoo(); fooDynamic on the other hand is created as a dynamic type and it's a completely different beast. I can also create a dynamic by simply casting any type to dynamic like this:DynamicFoo fooExplicit = new DynamicFoo(); dynamic fooDynamic = fooExplicit; Note that dynamic typically doesn't require an explicit cast as the compiler automatically performs the cast so there's no need to use as dynamic. Dynamic functionality works at runtime and allows for the dynamic wrapper to look up and call members dynamically. A dynamic type will look for members to access or call in two places: Using the strongly typed members of the object Using theIDynamicMetaObjectProvider Interface methods to access members So rather than statically linking and calling a method or retrieving a property, the dynamic type looks up - at runtime  - where the value actually comes from. It's essentially late-binding which allows runtime determination what action to take when a member is accessed at runtime *if* the member you are accessing does not exist on the object. Class members are checked first before IDynamicMetaObjectProvider interface methods are kick in. All of the following works with the dynamic type:dynamic fooDynamic = new DynamicFoo(); // dynamic typing assignments fooDynamic.NewProperty = "Something new!"; fooDynamic.LastAccess = DateTime.Now; // dynamic assigning static properties fooDynamic.Bar = "dynamic barred"; fooDynamic.Entered = DateTime.Now; // echo back dynamic values Console.WriteLine(fooDynamic.NewProperty); Console.WriteLine(fooDynamic.LastAccess); Console.WriteLine(fooDynamic.Bar); Console.WriteLine(fooDynamic.Entered); The dynamic type can access the native class properties (Bar and Entered) and create and read new ones (NewProperty,LastAccess) all using a single type instance which is pretty cool. As you can see it's pretty easy to create an extensible type this way that can dynamically add members at runtime dynamically. The Alter Ego of IDynamicObject The key point here is that all three statements - explicit, var and dynamic - declare a new DynamicFoo(), but the dynamic declaration results in completely different behavior than the first two simply because the type has been cast to dynamic. Dynamic binding means that the type loses its typical strong typing, compile time features. You can see this easily in the Visual Studio code editor. As soon as you assign a value to a dynamic you lose Intellisense and you see which means there's no Intellisense and no compiler type checking on any members you apply to this instance. If you're new to the dynamic type it might seem really confusing that a single type can behave differently depending on how it is cast, but that's exactly what happens when you use a type that implements IDynamicMetaObjectProvider. Declare the type as its strong type name and you only get to access the native instance members of the type. Declare or cast it to dynamic and you get dynamic behavior which accesses native members plus it uses IDynamicMetaObjectProvider implementation to handle any missing member definitions by running custom code. You can easily cast objects back and forth between dynamic and the original type:dynamic fooDynamic = new DynamicFoo(); fooDynamic.NewProperty = "New Property Value"; DynamicFoo foo = fooDynamic; foo.Bar = "Barred"; Here the code starts out with a dynamic cast and a dynamic assignment. The code then casts back the value to the DynamicFoo. Notice that when casting from dynamic to DynamicFoo and back we typically do not have to specify the cast explicitly - the compiler can induce the type so I don't need to specify as dynamic or as DynamicFoo. Moral of the Story This easy interchange between dynamic and the underlying type is actually super useful, because it allows you to create extensible objects that can expose non-member data stores and expose them as an object interface. You can create an object that hosts a number of strongly typed properties and then cast the object to dynamic and add additional dynamic properties to the same type at runtime. You can easily switch back and forth between the strongly typed instance to access the well-known strongly typed properties and to dynamic for the dynamic properties added at runtime. Keep in mind that dynamic object access has quite a bit of overhead and is definitely slower than strongly typed binding, so if you're accessing the strongly typed parts of your objects you definitely want to use a strongly typed reference. Reserve dynamic for the dynamic members to optimize your code. The real beauty of dynamic is that with very little effort you can build expandable objects or objects that expose different data stores to an object interface. I'll have more on this in my next post when I create a customized and extensible Expando object based on DynamicObject.© Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp  .NET   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • Easily use google maps, openstreet maps etc offline.

    - by samkea
    I did it and i am going to explain step by step. The explanatination may appear long but its simple if you follow. Note: All the softwares i have used are the latest and i have packaged them and provided them in the link below. I use Nokia N96 1) RootSign smartComGPS and install it on your phone(i havent provided the signer so that u wuld do some little work. i used Secman' rootsign). 2) Install Universal Maps Downloader, SmartCom OGF2 converter and OziExplorer 3.95.4s on my PC. a) UMD is used to download map tiles from any map source like googlemaps,opensourcemaps etc... and also combine the tiles into an image file like png,jpg,bmp etc... b) SmartCom OGF2 converter is used to convert the image file into a format usable on your mobile phone. c) OziExplorer will help you to calibrate the usable map file so that it can be used with GPS on your mobile phone without the use of internet. 3) Go to google maps or where u pick your maps and pan to the area of your interest. Zoom the map to at least 15 or 16 zoom level where you can see your area clearly and the streets. 4) copy this script in a notepad file and save it on your desktop: javascript:void(prompt('',gApplication.getMap().ge tCenter())); 5) Open the universal maps downloader. You will notice that you are required to add the: left longitude, right longitude,top latitude, bottom latitude. 6) On your map in google maps, doubleclick on the your prefered to most middle point. you will notice that the map will center in that area. 7) copy the script and paste it in the address bar then press enter. You will notice that a dialog with your (top latitude) and longitude respectively pops up. 8) copy the top latitude ONLY and paste it in the corresponding textbox in the UMD. 9) repeat steps 6-7 for the botton latitude. 10)repeat steps 6-7 for left longitude and right longitude too, but u have to copy the longitudes here. (***BTW record these points in the text file as they may be needed later in calibration) 11) Give the zoom level to the same zoom level that you prefered in google maps. 12) Dont forget to choose a path to save your files and under options set the proxy connection settings in UMD if you are using so. 13) Click on start and bingo! there you have your image tiles and a file with an extension .umd will be saved in the same folder. 14) On the UMD, go to tools, click on MapViewer and choose the .umd file. you will now see your map in one piece....and you will smile! 15) Still go to tools and click on map combiner. A dialog will popup for you to choose the .umd file and to enter the IMAGE file name. u can use another extension for the image file like png, jpg etc...i usually use png. 16) Combine.....bingo! there u go! u have an IMAGE file for your map. *I SUGGEST THAT CREATE A .BMP FILE and A .PNG file* 17) Close UMD and open SmartCom OGF2 converter. 18) Choose your .png image and create an ogf2 file. 19) Connect your phone to your PC in Mass Memory mode and transfer the file to the smartComGPS\Maps folder. 20) Now disconnect your phone and load smartComGPS. it will load the map and propt you to add a calibration point. Go ahead and add one calibration point with dummy coordinates. You will notice that it will add another file with extension .map in the smartComGPS\Maps folder. 21) Connect yiur ohone and copy that file and paste it in your working folder on your PC. Delete that .map file from the phone too because you are going to edit it from your PC and put it back. 22) Now Open the OziExplorer, go to file-->Load and Calibrate Map Image. 23) Choose the .bmp image and bingo! it will load with your map in the same zoom level. 24) Now you are going to calibrate. Use the MapView window and take the small box locater to all the 4 cornners of the map. You will notice that the map in the back ground moves to that area too. 25)On the right side, select the Point1 tab. Now you are in calibration mode. Now move the red box in mapview in the left upper corner to calibrate point1. 26) out of mapview go to the the left upper corner of the background map and choose poit (0,0) and your 1st calibration point. You will notice that these X,Y cordinated will be reflected in the Point1 image cordinates. 27) now go back to the text file where you saved your coordibates and enter the top latitude and the left longitude in the corresponding places. 28) Repeat steps 25-27 for point2,point3,point4 and click on save. Thats it, you have calibrated your image and you are about to finish. 29) Go to save and a dilaog which prompts you to save a .map file will poop up. Do save the map file in your working folder. 30) Right click that .map file and edit the filename in the .map file to remove the pc's directory structure. Eg. Change C\OziExplorer\data\Kampala.bmp to Kampala.ogf2. 31) Save the .map file in the smartComGPS\Maps folder on your phone. 32) now open smartComGPS on your phone and bingo! there is your map with GPS capability and in the same zoom level. 33) In smartComGPS options, choose connect and simulate. By now you should be smiling. Whoa! Hope i was of help. i case you get a problem, please inform me Below is the link to the software. regards. http://rapidshare.com/files/230296037/Utilities_Used.rar.html Ok, the Rapidshare files i posted are gone, so you will have to download as described in the solution. If you need more help, go here: http://www.dotsis.com/mobile_phone/sitemap/t-160491.html Some months later, someone else gave almost the same kind of solution here. http://www.dotsis.com/mobile_phone/sitemap/t-180123.html Note: the solutions were mean't to help view maps on Symbian phones, but i think now they ca even do for Windows Phones, iphones and others so read, extract what you want and use it. Hope it helps. Sam Kea

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  • Change or Reset Windows Password from a Ubuntu Live CD

    - by Trevor Bekolay
    If you can’t log in even after trying your twelve passwords, or you’ve inherited a computer complete with password-protected profiles, worry not – you don’t have to do a fresh install of Windows. We’ll show you how to change or reset your Windows password from a Ubuntu Live CD. This method works for all of the NT-based version of Windows – anything from Windows 2000 and later, basically. And yes, that includes Windows 7. You’ll need a Ubuntu 9.10 Live CD, or a bootable Ubuntu 9.10 Flash Drive. If you don’t have one, or have forgotten how to boot from the flash drive, check out our article on creating a bootable Ubuntu 9.10 flash drive. The program that lets us manipulate Windows passwords is called chntpw. The steps to install it are different in 32-bit and 64-bit versions of Ubuntu. Installation: 32-bit Open up Synaptic Package Manager by clicking on System at the top of the screen, expanding the Administration section, and clicking on Synaptic Package Manager. chntpw is found in the universe repository. Repositories are a way for Ubuntu to group software together so that users are able to choose if they want to use only completely open source software maintained by Ubuntu developers, or branch out and use software with different licenses and maintainers. To enable software from the universe repository, click on Settings > Repositories in the Synaptic window. Add a checkmark beside the box labeled “Community-maintained Open Source software (universe)” and then click close. When you change the repositories you are selecting software from, you have to reload the list of available software. In the main Synaptic window, click on the Reload button. The software lists will be downloaded. Once downloaded, Synaptic must rebuild its search index. The label over the text field by the Search button will read “Rebuilding search index.” When it reads “Quick search,” type chntpw in the text field. The package will show up in the list. Click on the checkbox near the chntpw name. Click on Mark for Installation. chntpw won’t actually be installed until you apply the changes you’ve made, so click on the Apply button in the Synaptic window now. You will be prompted to accept the changes. Click Apply. The changes should be applied quickly. When they’re done, click Close. chntpw is now installed! You can close Synaptic Package Manager. Skip to the section titled Using chntpw to reset your password. Installation: 64-bit The version of chntpw available in Ubuntu’s universe repository will not work properly on a 64-bit machine. Fortunately, a patched version exists in Debian’s Unstable branch, so let’s download it from there and install it manually. Open Firefox. Whether it’s your preferred browser or not, it’s very readily accessible in the Ubuntu Live CD environment, so it will be the easiest to use. There’s a shortcut to Firefox in the top panel. Navigate to http://packages.debian.org/sid/amd64/chntpw/download and download the latest version of chntpw for 64-bit machines. Note: In most cases it would be best to add the Debian Unstable branch to a package manager, but since the Live CD environment will revert to its original state once you reboot, it’ll be faster to just download the .deb file. Save the .deb file to the default location. You can close Firefox if desired. Open a terminal window by clicking on Applications at the top-left of the screen, expanding the Accessories folder, and clicking on Terminal. In the terminal window, enter the following text, hitting enter after each line: cd Downloadssudo dpkg –i chntpw* chntpw will now be installed. Using chntpw to reset your password Before running chntpw, you will have to mount the hard drive that contains your Windows installation. In most cases, Ubuntu 9.10 makes this simple. Click on Places at the top-left of the screen. If your Windows drive is easily identifiable – usually by its size – then left click on it. If it is not obvious, then click on Computer and check out each hard drive until you find the correct one. The correct hard drive will have the WINDOWS folder in it. When you find it, make a note of the drive’s label that appears in the menu bar of the file browser. If you don’t already have one open, start a terminal window by going to Applications > Accessories > Terminal. In the terminal window, enter the commands cd /medials pressing enter after each line. You should see one or more strings of text appear; one of those strings should correspond with the string that appeared in the title bar of the file browser earlier. Change to that directory by entering the command cd <hard drive label> Since the hard drive label will be very annoying to type in, you can use a shortcut by typing in the first few letters or numbers of the drive label (capitalization matters) and pressing the Tab key. It will automatically complete the rest of the string (if those first few letters or numbers are unique). We want to switch to a certain Windows directory. Enter the command: cd WINDOWS/system32/config/ Again, you can use tab-completion to speed up entering this command. To change or reset the administrator password, enter: sudo chntpw SAM SAM is the file that contains your Windows registry. You will see some text appear, including a list of all of the users on your system. At the bottom of the terminal window, you should see a prompt that begins with “User Edit Menu:” and offers four choices. We recommend that you clear the password to blank (you can always set a new password in Windows once you log in). To do this, enter “1” and then “y” to confirm. If you would like to change the password instead, enter “2”, then your desired password, and finally “y” to confirm. If you would like to reset or change the password of a user other than the administrator, enter: sudo chntpw –u <username> SAM From here, you can follow the same steps as before: enter “1” to reset the password to blank, or “2” to change it to a value you provide. And that’s it! Conclusion chntpw is a very useful utility provided for free by the open source community. It may make you think twice about how secure the Windows login system is, but knowing how to use chntpw can save your tail if your memory fails you two or eight times! Similar Articles Productive Geek Tips Reset Your Ubuntu Password Easily from the Live CDChange Your Forgotten Windows Password with the Linux System Rescue CDHow to Create and Use a Password Reset Disk in Windows Vista & Windows 7Reset Your Forgotten Password the Easy Way Using the Ultimate Boot CD for WindowsHow to install Spotify in Ubuntu 9.10 using Wine TouchFreeze Alternative in AutoHotkey The Icy Undertow Desktop Windows Home Server – Backup to LAN The Clear & Clean Desktop Use This Bookmarklet to Easily Get Albums Use AutoHotkey to Assign a Hotkey to a Specific Window Latest Software Reviews Tinyhacker Random Tips DVDFab 6 Revo Uninstaller Pro Registry Mechanic 9 for Windows PC Tools Internet Security Suite 2010 Add a Custom Title in IE using Spybot or Spyware Blaster When You Need to Hail a Taxi in NYC Live Map of Marine Traffic NoSquint Remembers Site Specific Zoom Levels (Firefox) New Firefox release 3.6.3 fixes 1 Critical bug Dark Side of the Moon (8-bit)

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  • C# in Depth, Third Edition by Jon Skeet, Manning Publications Co. Book Review

    - by Compudicted
    Originally posted on: http://geekswithblogs.net/Compudicted/archive/2013/10/24/c-in-depth-third-edition-by-jon-skeet-manning-publications.aspx I started reading this ebook on September 28, 2013, the same day it was sent my way by Manning Publications Co. for review while it still being fresh off the press. So 1st thing – thanks to Manning for this opportunity and a free copy of this must have on every C# developer’s desk book! Several hours ago I finished reading this book (well, except a for a large portion of its quite lengthy appendix). I jumped writing this review right away while still being full of emotions and impressions from reading it thoroughly and running code examples. Before I go any further I would like say that I used to program on various platforms using various languages starting with the Mainframe and ending on Windows, and I gradually shifted toward dealing with databases more than anything, however it happened with me to program in C# 1 a lot when it was first released and then some C# 2 with a big leap in between to C# 5. So my perception and experience reading this book may differ from yours. Also what I want to tell is somewhat funny that back then, knowing some Java and seeing C# 1 released, initially made me drawing a parallel that it is a copycat language, how wrong was I… Interestingly, Jon programs in Java full time, but how little it was mentioned in the book! So more on the book: Be informed, this is not a typical “Recipes”, “Cookbook” or any set of ready solutions, it is rather targeting mature, advanced developers who do not only know how to use a number of features, but are willing to understand how the language is operating “under the hood”. I must state immediately, at the same time I am glad the author did not go into the murky depths of the MSIL, so this is a very welcome decision on covering a modern language as C# for me, thank you Jon! Frankly, not all was that rosy regarding the tone and structure of the book, especially the the first half or so filled me with several negative and positive emotions overpowering each other. To expand more on that, some statements in the book appeared to be bias to me, or filled with pre-justice, it started to look like it had some PR-sole in it, but thankfully this was all gone toward the end of the 1st third of the book. Specifically, the mention on the C# language popularity, Java is the #1 language as per https://sites.google.com/site/pydatalog/pypl/PyPL-PopularitY-of-Programming-Language (many other sources put C at the top which I highly doubt), also many interesting functional languages as Clojure and Groovy appeared and gained huge traction which run on top of Java/JVM whereas C# does not enjoy such a situation. If we want to discuss the popularity in general and say how fast a developer can find a new job that pays well it would be indeed the very Java, C++ or PHP, never C#. Or that phrase on language preference as a personal issue? We choose where to work or we are chosen because of a technology used at a given software shop, not vice versa. The book though it technically very accurate with valid code, concise examples, but I wish the author would give more concrete, real-life examples on where each feature should be used, not how. Another point to realize before you get the book is that it is almost a live book which started to be written when even C# 3 wasn’t around so a lot of ground is covered (nearly half of the book) on the pre-C# 3 feature releases so if you already have a solid background in the previous releases and do not plan to upgrade, perhaps half of the book can be skipped, otherwise this book is surely highly recommended. Alas, for me it was a hard read, most of it. It was not boring (well, only may be two times), it was just hard to grasp some concepts, but do not get me wrong, it did made me pause, on several occasions, and made me read and re-read a page or two. At times I even wondered if I have any IQ at all (LOL). Be prepared to read A LOT on generics, not that they are widely used in the field (I happen to work as a consultant and went thru a lot of code at many places) I can tell my impression is the developers today in best case program using examples found at OpenStack.com. Also unlike the Java world where having the most recent version is nearly mandated by the OSS most companies on the Microsoft platform almost never tempted to upgrade the .Net version very soon and very often. As a side note, I was glad to see code recently that included a nullable variable (myvariable? notation) and this made me smile, besides, I recommended that person this book to expand her knowledge. The good things about this book is that Jon maintains an active forum, prepared code snippets and even a small program (Snippy) that is happy to run the sample code saving you from writing any plumbing code. A tad now on the C# language itself – it sure enjoyed a wonderful road toward perfection and a very high adoption, especially for ASP development. But to me all the recent features that made this statically typed language more dynamic look strange. Don’t we have F#? Which supposed to be the dynamic language? Why do we need to have a hybrid language? Now the developers live their lives in dualism of the static and dynamic variables! And LINQ to SQL, it is covered in depth, but wasn’t it supposed to be dropped? Also it seems that very little is being added, and at a slower pace, e.g. Roslyn will come in late 2014 perhaps, and will be probably the only main feature. Again, it is quite hard to read this book as various chapters, C# versions mentioned every so often only if I only could remember what was covered exactly where! So the fact it has so many jumps/links back and forth I recommend the ebook format to make the navigations easier to perform and I do recommend using software that allows bookmarking, also make sure you have access to plenty of coffee and pizza (hey, you probably know this joke – who a programmer is) ! In terms of closing, if you stuck at C# 1 or 2 level, it is time to embrace the power of C# 5! Finally, to compliment Manning, this book unlike from any other publisher so far, was the only one as well readable (put it formatted) on my tablet as in Adobe Reader on a laptop.

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  • Guide to Downloading Oracle Fusion Middleware 11g Products

    - by Daniel Mortimer
    IntroductionThe idea of writing a blog about downloading software seems a bit strange .. right? After all, surely just give me the web download link and away I go!? Unfortunately, life is not so simple if you are a DBA or Systems Administrator tasked with staging Oracle Fusion Middleware 11g products for your chosen business technology stack. Here are the challenges: Oracle Fusion Middleware is not a single product, it is a family of products - a media pack with many many "disks" - which ones do I pick? Are the products I pick certified / supported on my chosen platform? Which download site do I use? I need to be on the latest and greatest - how do I get hold of the latest product patch set? The purpose of this blog is to give you a roadmap to get you through these challenges. Oracle Fusion Middleware 11g - A Product SuiteThe first thing to appreciate is that Oracle Fusion Middleware 11g is not a single product. It is a product suite, an umbrella label for many products. Typically you don't download the whole media pack - well not unless you want to stage 124 Parts - a total of 68 Gig  - instead you pick the pieces that are required for your chosen Middleware solution. Therefore, you need to research / understand which products are required to build your solution. In this respect, before you go looking for the software pick and persue the product guide from the table below which matches your situation:  Installing a New / Vanilla FMW 11g architecture Oracle Fusion Middleware Installation Planning Guide 11g  Upgrading Oracle Application Server 10g to FMW 11g Oracle Fusion Middleware Upgrade Planning Guide 11g  Patching an existing FMW 11g architecture Oracle Fusion Middleware Patching Guide 11g Certification Information Ok, so now you have an idea of what Fusion Middleware products you need. It's time to check whether these products are certified against your chosen platform. There are two places to find this information:My Oracle Support Certification Tab PageFigure 1.1 My Oracle Support Certification Tab Page - "Search on SOA Suite" Figure 1.2 My Oracle Support Certification Tab Page - "SOA Suite Search Result" The FMW 11g Certification Central Hub (in the format of xls spreadsheet)Figure 2: Screenshot of FMW 11g Release 1 Certification xls spreadsheet Hints / Tips: Fusion Middleware 11g certification information has only recently been added into the Certification Tab page and I think it is the more friendly way to access the information. However, due to some restrictions with the Certification Tab page interface some of the more, let's say obscure certification information, is still to be only found in the Certification spreadsheet. Be aware that to find certification information via the My Oracle Support Certification Tab page you must enter the FMW 11g product name e.g. "Oracle SOA Suite". Do NOT enter "Oracle Fusion Middleware". The certification information does not exist at this product suite level.  For example, if you are building a solution which includes Oracle SOA Suite Oracle WebCenter then you will have to look up the certification information for each product in turn.After choosing the product name, select the latest patch set version. This will not only tell you whether your chosen product is available at that patch set version but provide the certification information relevant to that version.  If the product is not available under the latest patch set version, seek the information under previous patch set versions. Important: Make a careful note of the Oracle WebLogic Server version which is certified with your chosen product and patch set version. Oracle WebLogic Server is the core component of a Oracle Fusion Middleware 11g home. It is important therefore to ensure later on that you download the version of Oracle WebLogic Server which is compatible and certified with your chosen product and patch set version.Also - sorry to state the obvious, but please do not take certification information from the screenshots above. The screenshots are only good for the time they were entered into the blog. To ensure you have the latest information, interactively look up the certification details. For more information about finding certification information, bookmark and readMy Oracle Support Certification Tool for Oracle Fusion Middleware Products [Doc ID 1368736.1]How to Find Certification Details for Oracle Application Server 10g and Oracle Fusion Middleware 11g [Doc ID 431578.1] Downloading the Software Now you should be ready to download the software. There are two download locations Oracle Software Delivery Cloud (formerly known as E-Delivery)Figure 3 - Screenshot of Fusion Middleware Download from Delivery CloudOracle Fusion Middleware Download Page on Oracle Technology NetworkFigure 4 - Screenshot of OTN Product Download Screen Hints / Tips: Your choice of download location should be primarily driven by your licensing needs. Take note of the wording on the OTN site - to quote:"The downloads below are provided for evaluators under the OTN License Agreement. Licensed customers should download their software via our Oracle Software Delivery Cloud site, which offers different license terms."However, it has to be said that the presentation of the most of the product download pages on OTN does make the job easier. The Software Delivery Cloud provides you with a flat list of the Oracle Fusion Middleware 11g media pack. You have to know what you are looking for and pick out the right pieces :-( The OTN product download pages present not only the download for the product you want but also its dependencies such as WebLogic Server and Repository Creation Utility. So, even if your licensing requirements drive you towards the cloud, it is still worthwhile checking the OTN pages if only as a guide to what you need to pick out from the flat list found on the cloud site. Latest Patch Set This is an area which may cause you confusion - especially if you are more familiar with the Oracle Application Server 10g patching story. From Patch Set 11.1.1.6 and higher, the majority of FMW 11g products (N.B there are exceptions) provide installers which can be used both to update existing FMW 11g product installs or build brand new ones. This is good news because, unless you are dealing with one of the exceptions, it means you do not have to download base software and a patch set. At the time of the writing, the two significant exceptions are: Portal/Forms/Reports/Discoverer 11g Release 1 (11.1.1.x) Identity Access Management 11g Release 1 (11.1.1.x) The other key message here is ensure you are grabbing a version of Oracle WebLogic Server which is compatible with your chosen product patch set version. Get this wrong and you will hit errors / problems at AS Instance Configuration Time.The go to place is this document - Oracle Fusion Middleware Download, Installation, and Configuration Readme FilesIn fact, this README document pretty much takes you through what I have blogged above. The only thing is you need to know which README to choose, and that's why planning your FMW 11g technology stack and viewing certification information comes into play beforehand. And Finally As the Oracle Fusion Middleware Download, Installation, and Configuration Readme Files states don't forget to check FMW 11g System Requirements FMW 11g Product Interoperability

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  • SQL SERVER – Weekly Series – Memory Lane – #051

    - by Pinal Dave
    Here is the list of selected articles of SQLAuthority.com across all these years. Instead of just listing all the articles I have selected a few of my most favorite articles and have listed them here with additional notes below it. Let me know which one of the following is your favorite article from memory lane. 2007 Explanation and Understanding NOT NULL Constraint NOT NULL is integrity CONSTRAINT. It does not allow creating of the row where column contains NULL value. Most discussed questions about NULL is what is NULL? I will not go in depth analysis it. Simply put NULL is unknown or missing data. When NULL is present in database columns, it can affect the integrity of the database. I really do not prefer NULL in the database unless they are absolutely necessary. Three T-SQL Script to Create Primary Keys on Table I have always enjoyed writing about three topics Constraint and Keys, Backup and Restore and Datetime Functions. Primary Keys constraints prevent duplicate values for columns and provides a unique identifier to each column, as well it creates clustered index on the columns. 2008 Get Numeric Value From Alpha Numeric String – UDF for Get Numeric Numbers Only SQL is great with String operations. Many times, I use T-SQL to do my string operation. Let us see User Defined Function, which I wrote a few days ago, which will return only Numeric values from Alpha Numeric values. Introduction and Example of UNION and UNION ALL It is very much interesting when I get requests from blog reader to re-write my previous articles. I have received few requests to rewrite my article SQL SERVER – Union vs. Union All – Which is better for performance? with examples. I request you to read my previous article first to understand what is the concept and read this article to understand the same concept with an example. Downgrade Database for Previous Version The main questions is how they can downgrade the from SQL Server 2005 to SQL Server 2000? The answer is : Not Possible. Get Common Records From Two Tables Without Using Join Following is my scenario, Suppose Table 1 and Table 2 has same column e.g. Column1 Following is the query, 1. Select column1,column2 From Table1 2. Select column1 From Table2 I want to find common records from these tables, but I don’t want to use the Join clause because for that I need to specify the column name for Join condition. Will you help me to get common records without using Join condition? I am using SQL Server 2005. Retrieve – Select Only Date Part From DateTime – Best Practice – Part 2 A year ago I wrote a post about SQL SERVER – Retrieve – Select Only Date Part From DateTime – Best Practice where I have discussed two different methods of getting the date part from datetime. Introduction to CLR – Simple Example of CLR Stored Procedure CLR is an abbreviation of Common Language Runtime. In SQL Server 2005 and later version of it database objects can be created which are created in CLR. Stored Procedures, Functions, Triggers can be coded in CLR. CLR is faster than T-SQL in many cases. CLR is mainly used to accomplish tasks which are not possible by T-SQL or can use lots of resources. The CLR can be usually implemented where there is an intense string operation, thread management or iteration methods which can be complicated for T-SQL. Implementing CLR provides more security to the Extended Stored Procedure. 2009 Comic Slow Query – SQL Joke Before Presentation After Presentation Enable Automatic Statistic Update on Database In one of the recent projects, I found out that despite putting good indexes and optimizing the query, I could not achieve an optimized performance and I still received an unoptimized response from the SQL Server. On examination, I figured out that the culprit was statistics. The database that I was trying to optimize had auto update of the statistics was disabled. Recently Executed T-SQL Query Please refer to blog post  query to recently executed T-SQL query on database. Change Collation of Database Column – T-SQL Script – Consolidating Collations – Extention Script At some time in your DBA career, you may find yourself in a position when you sit back and realize that your database collations have somehow run amuck, or are faced with the ever annoying CANNOT RESOLVE COLLATION message when trying to join data of varying collation settings. 2010 Visiting Alma Mater – Delivering Session on Database Performance and Career – Nirma Institute of Technology Everyone always dreams of visiting their school and college, where they have studied once. It is a great feeling to see the college once again – where you have spent the wonderful golden years of your time. College time is filled with studies, education, emotions and several plans to build a future. I consider myself fortunate as I got the opportunity to study at some of the best places in the world. Change Column DataTypes There are times when I feel like writing that I am a day older in SQL Server. In fact, there are many who are looking for a solution that is simple enough. Have you ever searched online for something very simple. I often do and enjoy doing things which are straight forward and easy to change. 2011 Three DMVs – sys.dm_server_memory_dumps – sys.dm_server_services – sys.dm_server_registry In this blog post we will see three new DMVs which are introduced in Denali. The DMVs are very simple and there is not much to describe them. So here is the simple game. I will be asking a question back to you after seeing the result of the each of the DMV and you help me to complete this blog post. A Simple Quiz – T-SQL Brain Trick If you have some time, I strongly suggest you try this quiz out as it is for sure twists your brain. 2012 List All The Column With Specific Data Types in Database 5 years ago I wrote script SQL SERVER – 2005 – List All The Column With Specific Data Types, when I read it again, it is very much relevant and I liked it. This is one of the script which every developer would like to keep it handy. I have upgraded the script bit more. I have included few additional information which I believe I should have added from the beginning. It is difficult to visualize the final script when we are writing it first time. Find First Non-Numeric Character from String The function PATINDEX exists for quite a long time in SQL Server but I hardly see it being used. Well, at least I use it and I am comfortable using it. Here is a simple script which I use when I have to identify first non-numeric character. Finding Different ColumnName From Almost Identitical Tables Well here is the interesting example of how we can use sys.column catalogue views and get the details of the newly added column. I have previously written about EXCEPT over here which is very similar to MINUS of Oracle. Storing Data and Files in Cloud – Dropbox – Personal Technology Tip I thought long and hard about doing a Personal Technology Tips series for this blog.  I have so many tips I’d like to share.  I am on my computer almost all day, every day, so I have a treasure trove of interesting tidbits I like to share if given the chance.  The only thing holding me back – which tip to share first?  The first tip obviously has the weight of seeming like the most important.  But this would mean choosing amongst my favorite tricks and shortcuts.  This is a hard task. Reference: Pinal Dave (http://blog.sqlauthority.com) Filed under: Memory Lane, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL, Technology

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  • WCF – interchangeable data-contract types

    - by nmarun
    In a WSDL based environment, unlike a CLR-world, we pass around the ‘state’ of an object and not the reference of an object. Well firstly, what does ‘state’ mean and does this also mean that we can send a struct where a class is expected (or vice-versa) as long as their ‘state’ is one and the same? Let’s see. So I have an operation contract defined as below: 1: [ServiceContract] 2: public interface ILearnWcfServiceExtend : ILearnWcfService 3: { 4: [OperationContract] 5: Employee SaveEmployee(Employee employee); 6: } 7:  8: [ServiceBehavior] 9: public class LearnWcfService : ILearnWcfServiceExtend 10: { 11: public Employee SaveEmployee(Employee employee) 12: { 13: employee.EmployeeId = 123; 14: return employee; 15: } 16: } Quite simplistic operation there (which translates to ‘absolutely no business value’). Now, the data contract Employee mentioned above is a struct. 1: public struct Employee 2: { 3: public int EmployeeId { get; set; } 4:  5: public string FName { get; set; } 6: } After compilation and consumption of this service, my proxy (in the Reference.cs file) looks like below (I’ve ignored the rest of the details just to avoid unwanted confusion): 1: public partial struct Employee : System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged I call the service with the code below: 1: private static void CallWcfService() 2: { 3: Employee employee = new Employee { FName = "A" }; 4: Console.WriteLine("IsValueType: {0}", employee.GetType().IsValueType); 5: Console.WriteLine("IsClass: {0}", employee.GetType().IsClass); 6: Console.WriteLine("Before calling the service: {0} - {1}", employee.EmployeeId, employee.FName); 7: employee = LearnWcfServiceClient.SaveEmployee(employee); 8: Console.WriteLine("Return from the service: {0} - {1}", employee.EmployeeId, employee.FName); 9: } The output is: I now change my Employee type from a struct to a class in the proxy class and run the application: 1: public partial class Employee : System.Runtime.Serialization.IExtensibleDataObject, System.ComponentModel.INotifyPropertyChanged { The output this time is: The state of an object implies towards its composition, the properties and the values of these properties and not based on whether it is a reference type (class) or a value type (struct). And as shown above, we’re actually passing an object by its state and not by reference. Continuing on the same topic of ‘type-interchangeability’, WCF treats two data contracts as equivalent if they have the same ‘wire-representation’. We can do so using the DataContract and DataMember attributes’ Name property. 1: [DataContract] 2: public struct Person 3: { 4: [DataMember] 5: public int Id { get; set; } 6:  7: [DataMember] 8: public string FirstName { get; set; } 9: } 10:  11: [DataContract(Name="Person")] 12: public class Employee 13: { 14: [DataMember(Name = "Id")] 15: public int EmployeeId { get; set; } 16:  17: [DataMember(Name="FirstName")] 18: public string FName { get; set; } 19: } I’ve created two data contracts with the exact same wire-representation. Just remember that the names and the types of data members need to match to be considered equivalent. The question then arises as to what gets generated in the proxy class. Despite us declaring two data contracts (Person and Employee), only one gets emitted – Person. This is because we’re saying that the Employee type has the same wire-representation as the Person type. Also that the signature of the SaveEmployee operation gets changed on the proxy side: 1: [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "4.0.0.0")] 2: [System.ServiceModel.ServiceContractAttribute(ConfigurationName="ServiceProxy.ILearnWcfServiceExtend")] 3: public interface ILearnWcfServiceExtend 4: { 5: [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/ILearnWcfServiceExtend/SaveEmployee", ReplyAction="http://tempuri.org/ILearnWcfServiceExtend/SaveEmployeeResponse")] 6: ClientApplication.ServiceProxy.Person SaveEmployee(ClientApplication.ServiceProxy.Person employee); 7: } But, on the service side, the SaveEmployee still accepts and returns an Employee data contract. 1: [ServiceBehavior] 2: public class LearnWcfService : ILearnWcfServiceExtend 3: { 4: public Employee SaveEmployee(Employee employee) 5: { 6: employee.EmployeeId = 123; 7: return employee; 8: } 9: } Despite all these changes, our output remains the same as the last one: This is type-interchangeability at work! Here’s one more thing to ponder about. Our Person type is a struct and Employee type is a class. Then how is it that the Person type got emitted as a ‘class’ in the proxy? It’s worth mentioning that WSDL describes a type called Employee and does not say whether it is a class or a struct (see the SOAP message below): 1: <soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" 2: xmlns:tem="http://tempuri.org/" 3: xmlns:ser="http://schemas.datacontract.org/2004/07/ServiceApplication"> 4: <soapenv:Header/> 5: <soapenv:Body> 6: <tem:SaveEmployee> 7: <!--Optional:--> 8: <tem:employee> 9: <!--Optional:--> 10: <ser:EmployeeId>?</ser:EmployeeId> 11: <!--Optional:--> 12: <ser:FName>?</ser:FName> 13: </tem:employee> 14: </tem:SaveEmployee> 15: </soapenv:Body> 16: </soapenv:Envelope> There are some differences between how ‘Add Service Reference’ and the svcutil.exe generate the proxy class, but turns out both do some kind of reflection and determine the type of the data contract and emit the code accordingly. So since the Employee type is a class, the proxy ‘Person’ type gets generated as a class. In fact, reflecting on svcutil.exe application, you’ll see that there are a couple of places wherein a flag actually determines a type as a class or a struct. One example is in the ExportISerializableDataContract method in the System.Runtime.Serialization.CodeExporter class. Seems like these flags have a say in deciding whether the type gets emitted as a struct or a class. This behavior is different if you use the WSDL tool though. WSDL tool does not do any kind of reflection of the data contract / serialized type, it emits the type as a class by default. You can check this using the two command lines below:   Note to self: Remember ‘state’ and type-interchangeability when traversing through the WSDL planet!

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  • Developer’s Life – Attitude and Communication – They Can Cause Problems – Notes from the Field #027

    - by Pinal Dave
    [Note from Pinal]: This is a 27th episode of Notes from the Field series. The biggest challenge for anyone is to understand human nature. We human have so many things on our mind at any moment of time. There are cases when what we say is not what we mean and there are cases where what we mean we do not say. We do say and things as per our mood and our agenda in mind. Sometimes there are incidents when our attitude creates confusion in the communication and we end up creating a situation which is absolutely not warranted. In this episode of the Notes from the Field series database expert Mike Walsh explains a very crucial issue we face in our career, which is not technical but more to relate to human nature. Read on this may be the best blog post you might read in recent times. In this week’s note from the field, I’m taking a slight departure from technical knowledge and concepts explained. We’ll be back to it next week, I’m sure. Pinal wanted us to explain some of the issues we bump into and how we see some of our customers arrive at problem situations and how we have helped get them back on the right track. Often it is a technical problem we are officially solving – but in a lot of cases as a consultant, we are really helping fix some communication difficulties. This is a technical blog post and not an “advice column” in a newspaper – but the longer I am a consultant, the more years I add to my experience in technology the more I learn that the vast majority of the problems we encounter have “soft skills” included in the chain of causes for the issue we are helping overcome. This is not going to be exhaustive but I hope that sharing four pieces of advice inspired by real issues starts a process of searching for places where we can be the cause of these challenges and look at fixing them in ourselves. Or perhaps we can begin looking at resolving them in teams that we manage. I’ll share three statements that I’ve either heard, read or said and talk about some of the communication or attitude challenges highlighted by the statement. 1 – “But that’s the SAN Administrator’s responsibility…” I heard that early on in my consulting career when talking with a customer who had serious corruption and no good recent backups – potentially no good backups at all. The statement doesn’t have to be this one exactly, but the attitude here is an attitude of “my job stops here, and I don’t care about the intent or principle of why I’m here.” It’s also a situation of having the attitude that as long as there is someone else to blame, I’m fine…  You see in this case, the DBA had a suspicion that the backups were not being handled right.  They were the DBA and they knew that they had responsibility to ensure SQL backups were good to go – it’s a basic requirement of a production DBA. In my “As A DBA Where Do I start?!” presentation, I argue that is job #1 of a DBA. But in this case, the thought was that there was someone else to blame. Rather than create extra work and take on responsibility it was decided to just let it be another team’s responsibility. This failed the company, the company’s customers and no one won. As technologists – we should strive to go the extra mile. If there is a lack of clarity around roles and responsibilities and we know it – we should push to get it resolved. Especially as the DBAs who should act as the advocates of the data contained in the databases we are responsible for. 2 – “We’ve always done it this way, it’s never caused a problem before!” Complacency. I have to say that many failures I’ve been paid good money to help recover from would have not happened had it been for an attitude of complacency. If any thoughts like this have entered your mind about your situation you may be suffering from it. If, while reading this, you get this sinking feeling in your stomach about that one thing you know should be fixed but haven’t done it.. Why don’t you stop and go fix it then come back.. “We should have better backups, but we’re on a SAN so we should be fine really.” “Technically speaking that could happen, but what are the chances?” “We’ll just clean that up as a fast follow” ..and so on. In the age of tightening IT budgets, increased expectations of up time, availability and performance there is no room for complacency. Our customers and business units expect – no demand – the best. Complacency says “we will give you second best or hopefully good enough and we accept the risk and know this may hurt us later. Sometimes an organization will opt for “good enough” and I agree with the concept that at times the perfect can be the enemy of the good. But when we make those decisions in a vacuum and are not reporting them up and discussing them as an organization that is different. That is us unilaterally choosing to do something less than the best and purposefully playing a game of chance. 3 – “This device must accept interference from other devices but not create any” I’ve paraphrased this one – but it’s something the Federal Communications Commission – a federal agency in the United States that regulates electronic communication – requires of all manufacturers of any device that could cause or receive interference electronically. I blogged in depth about this here (http://www.straightpathsql.com/archives/2011/07/relationship-advice-from-the-fcc/) so I won’t go into much detail other than to say this… If we all operated more on the premise that we should do our best to not be the cause of conflict, and to be less easily offended and less upset when we perceive offense life would be easier in many areas! This doesn’t always cause the issues we are called in to help out. Not directly. But where we see it is in unhealthy relationships between the various technology teams at a client. We’ll see teams hoarding knowledge, not sharing well with others and almost working against other teams instead of working with them. If you trace these problems back far enough it often stems from someone or some group of people violating this principle from the FCC. To Sum It Up Technology problems are easy to solve. At Linchpin People we help many customers get past the toughest technological challenge – and at the end of the day it is really just a repeatable process of pattern based troubleshooting, logical thinking and starting at the beginning and carefully stepping through to the end. It’s easy at the end of the day. The tough part of what we do as consultants is the people skills. Being able to help get teams working together, being able to help teams take responsibility, to improve team to team communication? That is the difficult part, and we get to use the soft skills on every engagement. Work on professional development (http://professionaldevelopment.sqlpass.org/) and see continuing improvement here, not just with technology. I can teach just about anyone how to be an excellent DBA and performance tuner, but some of these soft skills are much more difficult to teach. If you want to get started with performance analytics and triage of virtualized SQL Servers with the help of experts, read more over at Fix Your SQL Server. Reference: Pinal Dave (http://blog.sqlauthority.com)Filed under: Notes from the Field, PostADay, SQL, SQL Authority, SQL Query, SQL Server, SQL Tips and Tricks, T SQL

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  • Speaker at the German Visual FoxPro Developer Conference 2004

    The following is an excerpt from the UniversalThread conference coverage of the German Visual FoxPro Developer Conference 2004 written by Hans-Otto Lochmann, Armin Neudert and myself. TRACK Active FoxPro Pages Back in 1996 Peter Herzog invented a FoxPro based solution to provide intranet capabilities for one of his customers. Nearly at the same time Rick Strahl had the same task and created WestWind Web Connection (WWWC). The aspect that developers have to have a full Visual FoxPro development environment to create WWWC solutions was the starting point of a "personal sportive competition" of Peter to write his own solution. But the main aspect has to be that it doesn't rely on a full VFP version in order to run. The VFP runtime should enough and the source code has to be compiled and interpreted on the fly. So, as Microsoft released Active Server Pages a name for Peter's solution was found: Active FoxPro Pages (AFP). During the years many drawbacks, design aspects as well as technological hassles forced ProLib Software to refactor the product. This way many limits like DCOM configuration, file-based information transfer between Web server and AFP, missing features (like upload forms or other Web servers than IIS) and extensibility were eliminated. As a consequence ProLib Software decided to rewrite Active FoxPro Pages in mid of 2002 completely. Christof Wollenhaupt, before his marriage known as Christof Lange, and Jochen Kirstätter had to solve this task. AFP 3.0 was officially released at German Devcon in November 2002. Today AFP has six distributors world-wide and there is a lot more information available online than before version 3.0. Directly after a short welcome speech by Rainer Becker, Jochen Kirstätter - aka JoKi - opened today's AFP track and introduced the basic concepts how Active FoxPro Pages works in general, explained the AFP terminilogy and every single component, and presented a small Walk-Through about how to write an AFP-based Web solution. Actually his presentation slides themselves were an AFP Web application. This way it was easy to integrate accompanying AFP samples on the fly. Additionally it was shown that no Visual FoxPro development environment is needed to create a Web application. A simple text editor like NotePad or any WYSIWYG editor on the market is usable to fullfil customer's requirements.Welcome at least two new speakers - Nina Schwanzer and Bernhard Reiter. Both are working at ProLib Software and this year's conference is their first time as speakers. And they did their job very well. The whole session was kind of a "ping pong" game and those two complemented each other to keep the audience in tension. First, they described typical requirements a modern desktop application should fullfil - online registration and activation, auto-update capabilities, or even frontend to administer a Web application on a remote system via internet, and explained how possible solutions like Web Services (using the SOAP interface), DCOM, and even .NET might solve those requirements. But any of those ways has different drawbacks like complicated installation or configuration, or extraordinary download sizes. Next, they introduced a technology they developed and used in a customer's project: Active FoxPro Pages Remote Procedure Call (AFP RPC). [...]   In the next session JoKi described how to extend Active FoxPro Pages. On the one hand AFP provides a plugin interface, and on the other hand any addon for Visual FoxPro might be usable as well. During the first half he spoke about the plugin interface and wrote live a new AFP extension - the Devcon plugin. Later he questioned any former step and showed that a single AFP document may solve the problem as well. So, developing extensions is only interesting if they are re-usable and generic. At the end he talked about multiple interfaces for the same business logic. For instance plain VFP class, COM server and .NET integration. Currently there are several specialized AFP extensions for sending mail, for using cryptographic routines (ie. based on .NET classes), or enhanced methods to handle HTML/XML strings.Rainer Becker and Peter Herzog introduced a new development for Visual Extend (VFX) - an AFP form builder. With this builder creating an AFP Web form designed with Visual FoxPro's form designer was a matter of seconds. The builder itself is currently in pre-release status and will be part of the VFX framework in the future. It was very impressive to see that the whole design of a form as well as most parts of its functionality were exported to a combination of HTML, JavaScript and Active FoxPro Pages. At half-time Jürgen "wOOdy" Wondzinski and JoKi changed places with Rainer and Peter, and presented some Web solutions in AFP. [...] Visual FoxPro 9.0 und Linux Is Linux still a topic for Visual FoxPro developers based on the activities during this year? In his session Jochen Kirstätter - aka JoKi - went not through the technical steps and requirements on how to setup and run FoxPro on a Linux client. Instead, he explained what Linux actually is, and talked about the high variety of distributions. In fact there are a lot of distributions around but since some several years there are some specialized ones available: Live Distributions (aka LiveCDs).The intension of LiveCDs is to run a full-featured Linux operating system on any personal computer directly from a bootable medium, like CD, DVD, or even USB memory stick, without installation on a hard disk. One of the first Linux LiveCDs was made by Klaus Knopper and is well-known as Knoppix. Today, many other LiveCDs are based on the concepts of Knoppix. During the session Jochen booted Morphix, a very light-weighted LiveCD, on his notebook, and actually showed the attendees that testing and playing around with Linux is absolutely easy. Running a text processing application swept away most of the contrary aspects the audience had. Okay, where is the part about FoxPro? Well, there are several scenarios a customer might require usage of Linux, and actually with all of them FoxPro could deal with. I guess that one of the more common ones is the situation that a customer has a heterogeneous intranet with Windows clients and Linux servers, i.e. Windows XP Professional and any Linux distribution on their servers. Even in this scenario there are two variants hidden! Why? Well, on the one hand there is a software package called Samba, that provides Windows server capabilities to a Linux system, and on the other hand there are several SQL servers for Linux, like PostgreSQL, DB2 and MySQL. Either way, FoxPro is able to deal with these scenarios, but you as developer have to know what you are talking about with your customers. And even if there's no Windows operating system, you are able to provide a FoxPro-based solution. Using the wine library - wine stands for Wine Is Not an Emulator - you are able to run your VFP applications on Linux clients, too; but not without reading VFP's EULA. Licenses were also part the session, and Jochen discussed the meaning of Open Source and its misunderstanding throughout most developers. Open Source does not mean that it's without a fee. Instead, it stands for access to the source code of an application or tool. And, VFP itself is one of the best samples to explain Open Source due to fact that since years, VFP is shipped with the xSource.zip archive. [...]

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  • DialogFX: A New Approach to JavaFX Dialogs

    - by HecklerMark
    How would you like a quick and easy drop-in dialog box capability for JavaFX? That's what I was thinking when a weekend presented itself. And never being one to waste a good weekend...  :-) After doing some "roll-your-own" basic dialog building for a JavaFX app, I recently stumbled across Anton Smirnov's work on GitHub. It was a good start, but it wasn't exactly what I was after, and ideas just kept popping up of things I'd do differently. I wanted something a bit more streamlined, a bit easier to just "drop in and use". And so DialogFX was born. DialogFX wasn't intended to be overly fancy, overly clever - just useful and robust. Here were my goals: Easy to use. A dialog "system" should be so simple to use a new developer can drop it in quickly with nearly no learning curve. A seasoned developer shouldn't even have to think, just tap in a few lines and go. Why should dialogs slow "actual development"?  :-) Defaults. If you don't specify something (dialog type, buttons, etc.), a good dialog system should still work. It may not be pretty, but it shouldn't throw gears. Sharable. It's all open source. Even the icons are in the commons, so they can be reused at will. Let's take a look at some screen captures and the code used to produce them.   DialogFX INFO dialog Screen captures Windows Mac  Sample code         DialogFX dialog = new DialogFX();        dialog.setTitleText("Info Dialog Box Example");        dialog.setMessage("This is an example of an INFO dialog box, created using DialogFX.");        dialog.showDialog(); DialogFX ERROR dialog Screen captures Windows Mac  Sample code         DialogFX dialog = new DialogFX(Type.ERROR);        dialog.setTitleText("Error Dialog Box Example");        dialog.setMessage("This is an example of an ERROR dialog box, created using DialogFX.");        dialog.showDialog(); DialogFX ACCEPT dialog Screen captures Windows Mac  Sample code         DialogFX dialog = new DialogFX(Type.ACCEPT);        dialog.setTitleText("Accept Dialog Box Example");        dialog.setMessage("This is an example of an ACCEPT dialog box, created using DialogFX.");        dialog.showDialog(); DialogFX Question dialog (Yes/No) Screen captures Windows Mac  Sample code         DialogFX dialog = new DialogFX(Type.QUESTION);        dialog.setTitleText("Question Dialog Box Example");        dialog.setMessage("This is an example of an QUESTION dialog box, created using DialogFX. Would you like to continue?");        dialog.showDialog(); DialogFX Question dialog (custom buttons) Screen captures Windows Mac  Sample code         List<String> buttonLabels = new ArrayList<>(2);        buttonLabels.add("Affirmative");        buttonLabels.add("Negative");         DialogFX dialog = new DialogFX(Type.QUESTION);        dialog.setTitleText("Question Dialog Box Example");        dialog.setMessage("This is an example of an QUESTION dialog box, created using DialogFX. This also demonstrates the automatic wrapping of text in DialogFX. Would you like to continue?");        dialog.addButtons(buttonLabels, 0, 1);        dialog.showDialog(); A couple of things to note You may have noticed in that last example the addButtons(buttonLabels, 0, 1) call. You can pass custom button labels in and designate the index of the default button (responding to the ENTER key) and the cancel button (for ESCAPE). Optional parameters, of course, but nice when you may want them. Also, the showDialog() method actually returns the index of the button pressed. Rather than create EventHandlers in the dialog that really have little to do with the dialog itself, you can respond to the user's choice within the calling object. Or not. Again, it's your choice.  :-) And finally, I've Javadoc'ed the code in the main places. Hopefully, this will make it easy to get up and running quickly and with a minimum of fuss. How Do I Get (Git?) It? To try out DialogFX, just point your browser here to the DialogFX GitHub repository and download away! Please take a look, try it out, and let me know what you think. All feedback welcome! All the best, Mark 

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  • Why It Is So Important to Know Your Customer

    - by Christie Flanagan
    Over the years, I endured enough delayed flights, air turbulence and misadventures in airport security clearance to watch my expectations for the air travel experience fall to abysmally low levels. The extent of my loyalty to any one carrier had more to do with the proximity of the airport parking garage to their particular gate than to any effort on the airline’s part to actually earn and retain my business. That all changed one day when I found myself at the airport hoping to catch a return flight home a few hours earlier than expected, using an airline I had flown with for the first time just that week.  When you travel regularly for business, being able to catch a return flight home that’s even an hour or two earlier than originally scheduled is a big deal. It can mean the difference between having a normal evening with your family and having to sneak in like a cat burglar after everyone is fast asleep. And so I found myself on this particular day hoping to catch an earlier flight home. I approached the gate agent and was told that I could go on standby for their next flight out. Then I asked how much it was going to cost to change the flight, knowing full well that I wouldn’t get reimbursed by my company for any change fees. “Oh, there’s no charge to fly on standby,” the gate agent told me. I made a funny look. I couldn’t believe what I was hearing. This airline was going to let my fly on standby, at no additional charge, even though I was a new customer with no status or points. It had been years since I’d seen an airline pass up a short term revenue generating opportunity in favor of a long term loyalty generating one.  At that moment, this particular airline gained my loyal business. Since then, this airline has had the opportunity to learn a lot about me. They know where I live, where I fly from, where I usually fly to, and where I like to sit on the plane. In general, I’ve found their customer service to be quite good whether at the airport, via call center and even through social channels. They email me occasionally, and when they do, they demonstrate that they know me by promoting deals for flights from where I live to places that I’d be interested in visiting. And that’s part of why I’m always so puzzled when I visit their website.Does this company with the great service, customer friendly policies, and clean planes demonstrate that they know me at all when I visit their website? The answer is no. Even when I log in using my loyalty program credentials, it’s pretty obvious that they’re presenting the same old home page and same old offers to every single one of their site visitors. I mean, those promotional offers that they’re featuring so prominently  -- they’re for flights that originate thousands of miles from where I live! There’s no way I’d ever book one of those flights and I’m sure I’m not the only one of their customers to feel that way.My reason for recounting this story is not to pick on the one customer experience flaw I've noticed with this particular airline, in fact, they do so many things right that I’ll continue to fly with them. But I did want to illustrate just how glaringly obvious it is to customers today when a touch point they have with a brand is impersonal, unconnected and out of sync. As someone who’s spent a number of years in the web experience management and online marketing space, it particularly peeves me when that out of sync touch point is a brand’s website, perhaps because I know how important it is to make a customer’s online experience relevant and how many powerful tools are available for making a relevant experience a reality. The fact is, delivering a one-size-fits-all online customer experience is no longer acceptable or particularly effective in today’s world. Today’s savvy customers expect you to know who they are and to understand their preferences, behavior and relationship with your brand. Not only do they expect you to know about them, but they also expect you to demonstrate this knowledge across all of their touch points with your brand in a consistent and compelling fashion, whether it be on your traditional website, your mobile web presence or through various social channels.Delivering the kind of personalized online experiences that customers want can have tremendous business benefits. This is not just about generating feelings of goodwill and higher customer satisfaction ratings either. More relevant and personalized online experiences boost the effectiveness of online marketing initiatives and the statistics prove this out. Personalized web experiences can help increase online conversion rates by 70% -- that’s a huge number.1  And more than three quarters of consumers indicate that they’ve made additional online purchases based on personalized product recommendations.2Now if only this airline would get on board with delivering a more personalized online customer experience. I’d certainly be happier and more likely to spring for one of their promotional offers. And by targeting relevant offers on their home page to appropriate segments of their site visitors, I bet they’d be happier and generating additional revenue too. 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-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}  ***** If you're interested in hearing more perspectives on the benefits of demonstrating that you know your customers by delivering a more personalized experience, check out this white paper on creating a successful and meaningful customer experience on the web.  Also catch the video below on the business value of CX in attracting new customers featuring Oracle's VP of Customer Experience Strategy, Brian Curran. 1 Search Engine Watch 2 Marketing Charts

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  • Dynamic Code for type casting Generic Types 'generically' in C#

    - by Rick Strahl
    C# is a strongly typed language and while that's a fundamental feature of the language there are more and more situations where dynamic types make a lot of sense. I've written quite a bit about how I use dynamic for creating new type extensions: Dynamic Types and DynamicObject References in C# Creating a dynamic, extensible C# Expando Object Creating a dynamic DataReader for dynamic Property Access Today I want to point out an example of a much simpler usage for dynamic that I use occasionally to get around potential static typing issues in C# code especially those concerning generic types. TypeCasting Generics Generic types have been around since .NET 2.0 I've run into a number of situations in the past - especially with generic types that don't implement specific interfaces that can be cast to - where I've been unable to properly cast an object when it's passed to a method or assigned to a property. Granted often this can be a sign of bad design, but in at least some situations the code that needs to be integrated is not under my control so I have to make due with what's available or the parent object is too complex or intermingled to be easily refactored to a new usage scenario. Here's an example that I ran into in my own RazorHosting library - so I have really no excuse, but I also don't see another clean way around it in this case. A Generic Example Imagine I've implemented a generic type like this: public class RazorEngine<TBaseTemplateType> where TBaseTemplateType : RazorTemplateBase, new() You can now happily instantiate new generic versions of this type with custom template bases or even a non-generic version which is implemented like this: public class RazorEngine : RazorEngine<RazorTemplateBase> { public RazorEngine() : base() { } } To instantiate one: var engine = new RazorEngine<MyCustomRazorTemplate>(); Now imagine that the template class receives a reference to the engine when it's instantiated. This code is fired as part of the Engine pipeline when it gets ready to execute the template. It instantiates the template and assigns itself to the template: var template = new TBaseTemplateType() { Engine = this } The problem here is that possibly many variations of RazorEngine<T> can be passed. I can have RazorTemplateBase, RazorFolderHostTemplateBase, CustomRazorTemplateBase etc. as generic parameters and the Engine property has to reflect that somehow. So, how would I cast that? My first inclination was to use an interface on the engine class and then cast to the interface.  Generally that works, but unfortunately here the engine class is generic and has a few members that require the template type in the member signatures. So while I certainly can implement an interface: public interface IRazorEngine<TBaseTemplateType> it doesn't really help for passing this generically templated object to the template class - I still can't cast it if multiple differently typed versions of the generic type could be passed. I have the exact same issue in that I can't specify a 'generic' generic parameter, since there's no underlying base type that's common. In light of this I decided on using object and the following syntax for the property (and the same would be true for a method parameter): public class RazorTemplateBase :MarshalByRefObject,IDisposable { public object Engine {get;set; } } Now because the Engine property is a non-typed object, when I need to do something with this value, I still have no way to cast it explicitly. What I really would need is: public RazorEngine<> Engine { get; set; } but that's not possible. Dynamic to the Rescue Luckily with the dynamic type this sort of thing can be mitigated fairly easily. For example here's a method that uses the Engine property and uses the well known class interface by simply casting the plain object reference to dynamic and then firing away on the properties and methods of the base template class that are common to all templates:/// <summary> /// Allows rendering a dynamic template from a string template /// passing in a model. This is like rendering a partial /// but providing the input as a /// </summary> public virtual string RenderTemplate(string template,object model) { if (template == null) return string.Empty; // if there's no template markup if(!template.Contains("@")) return template; // use dynamic to get around generic type casting dynamic engine = Engine; string result = engine.RenderTemplate(template, model); if (result == null) throw new ApplicationException("RenderTemplate failed: " + engine.ErrorMessage); return result; } Prior to .NET 4.0  I would have had to use Reflection for this sort of thing which would have a been a heck of a lot more verbose, but dynamic makes this so much easier and cleaner and in this case at least the overhead is negliable since it's a single dynamic operation on an otherwise very complex operation call. Dynamic as  a Bailout Sometimes this sort of thing often reeks of a design flaw, and I agree that in hindsight this could have been designed differently. But as is often the case this particular scenario wasn't planned for originally and removing the generic signatures from the base type would break a ton of other code in the framework. Given the existing fairly complex engine design, refactoring an interface to remove generic types just to make this particular code work would have been overkill. Instead dynamic provides a nice and simple and relatively clean solution. Now if there were many other places where this occurs I would probably consider reworking the code to make this cleaner but given this isolated instance and relatively low profile operation use of dynamic seems a valid choice for me. This solution really works anywhere where you might end up with an inheritance structure that doesn't have a common base or interface that is sufficient. In the example above I know what I'm getting but there's no common base type that I can cast to. All that said, it's a good idea to think about use of dynamic before you rush in. In many situations there are alternatives that can still work with static typing. Dynamic definitely has some overhead compared to direct static access of objects, so if possible we should definitely stick to static typing. In the example above the application already uses dynamics extensively for dynamic page page templating and passing models around so introducing dynamics here has very little additional overhead. The operation itself also fires of a fairly resource heavy operation where the overhead of a couple of dynamic member accesses are not a performance issue. So, what's your experience with dynamic as a bailout mechanism? © Rick Strahl, West Wind Technologies, 2005-2012Posted in CSharp   Tweet !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src="//platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); (function() { var po = document.createElement('script'); po.type = 'text/javascript'; po.async = true; po.src = 'https://apis.google.com/js/plusone.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(po, s); })();

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  • readonly keyword

    - by nmarun
    This is something new that I learned about the readonly keyword. Have a look at the following class: 1: public class MyClass 2: { 3: public string Name { get; set; } 4: public int Age { get; set; } 5:  6: private readonly double Delta; 7:  8: public MyClass() 9: { 10: Initializer(); 11: } 12:  13: public MyClass(string name = "", int age = 0) 14: { 15: Name = name; 16: Age = age; 17: Initializer(); 18: } 19:  20: private void Initializer() 21: { 22: Delta = 0.2; 23: } 24: } I have a couple of public properties and a private readonly member. There are two constructors – one that doesn’t take any parameters and the other takes two parameters to initialize the public properties. I’m also calling the Initializer method in both constructors to initialize the readonly member. Now when I build this, the code breaks and the Error window says: “A readonly field cannot be assigned to (except in a constructor or a variable initializer)” Two things after I read this message: It’s such a negative statement. I’d prefer something like: “A readonly field can be assigned to (or initialized) only in a constructor or through a variable initializer” But in my defense, I AM assigning it in a constructor (only indirectly). All I’m doing is creating a method that does it and calling it in a constructor. Turns out, .net was not ‘frameworked’ this way. We need to have the member initialized directly in the constructor. If you have multiple constructors, you can just use the ‘this’ keyword on all except the default constructors to call the default constructor. This default constructor can then initialize your readonly members. This will ensure you’re not repeating the code in multiple places. A snippet of what I’m talking can be seen below: 1: public class Person 2: { 3: public int UniqueNumber { get; set; } 4: public string Name { get; set; } 5: public int Age { get; set; } 6: public DateTime DateOfBirth { get; set; } 7: public string InvoiceNumber { get; set; } 8:  9: private readonly string Alpha; 10: private readonly int Beta; 11: private readonly double Delta; 12: private readonly double Gamma; 13:  14: public Person() 15: { 16: Alpha = "FDSA"; 17: Beta = 2; 18: Delta = 3.0; 19: Gamma = 0.0989; 20: } 21:  22: public Person(int uniqueNumber) : this() 23: { 24: UniqueNumber = uniqueNumber; 25: } 26: } See the syntax in line 22 and you’ll know what I’m talking about. So the default constructor gets called before the one in line 22. These are known as constructor initializers and they allow one constructor to call another. The other ‘myth’ I had about readonly members is that you can set it’s value only once. This was busted as well (I recall Adam and Jamie’s show). Say you’ve initialized the readonly member through a variable initializer. You can over-write this value in any of the constructors any number of times. 1: public class Person 2: { 3: public int UniqueNumber { get; set; } 4: public string Name { get; set; } 5: public int Age { get; set; } 6: public DateTime DateOfBirth { get; set; } 7: public string InvoiceNumber { get; set; } 8:  9: private readonly string Alpha = "asdf"; 10: private readonly int Beta = 15; 11: private readonly double Delta = 0.077; 12: private readonly double Gamma = 1.0; 13:  14: public Person() 15: { 16: Alpha = "FDSA"; 17: Beta = 2; 18: Delta = 3.0; 19: Gamma = 0.0989; 20: } 21:  22: public Person(int uniqueNumber) : this() 23: { 24: UniqueNumber = uniqueNumber; 25: Beta = 3; 26: } 27:  28: public Person(string name, DateTime dob) : this() 29: { 30: Name = name; 31: DateOfBirth = dob; 32:  33: Alpha = ";LKJ"; 34: Gamma = 0.0898; 35: } 36:  37: public Person(int uniqueNumber, string name, int age, DateTime dob, string invoiceNumber) : this() 38: { 39: UniqueNumber = uniqueNumber; 40: Name = name; 41: Age = age; 42: DateOfBirth = dob; 43: InvoiceNumber = invoiceNumber; 44:  45: Alpha = "QWER"; 46: Beta = 5; 47: Delta = 1.0; 48: Gamma = 0.0; 49: } 50: } In the above example, every constructor over-writes the values for the readonly members. This is perfectly valid. There is a possibility that based on the way the object is instantiated, the readonly member will have a different value. Well, that’s all I have for today and read this as it’s on a related topic.

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  • Using Table-Valued Parameters in SQL Server

    - by Jesse
    I work with stored procedures in SQL Server pretty frequently and have often found myself with a need to pass in a list of values at run-time. Quite often this list contains a set of ids on which the stored procedure needs to operate the size and contents of which are not known at design time. In the past I’ve taken the collection of ids (which are usually integers), converted them to a string representation where each value is separated by a comma and passed that string into a VARCHAR parameter of a stored procedure. The body of the stored procedure would then need to parse that string into a table variable which could be easily consumed with set-based logic within the rest of the stored procedure. This approach works pretty well but the VARCHAR variable has always felt like an un-wanted “middle man” in this scenario. Of course, I could use a BULK INSERT operation to load the list of ids into a temporary table that the stored procedure could use, but that approach seems heavy-handed in situations where the list of values is usually going to contain only a few dozen values. Fortunately SQL Server 2008 introduced the concept of table-valued parameters which effectively eliminates the need for the clumsy middle man VARCHAR parameter. Example: Customer Transaction Summary Report Let’s say we have a report that can summarize the the transactions that we’ve conducted with customers over a period of time. The report returns a pretty simple dataset containing one row per customer with some key metrics about how much business that customer has conducted over the date range for which the report is being run. Sometimes the report is run for a single customer, sometimes it’s run for all customers, and sometimes it’s run for a handful of customers (i.e. a salesman runs it for the customers that fall into his sales territory). This report can be invoked from a website on-demand, or it can be scheduled for periodic delivery to certain users via SQL Server Reporting Services. Because the report can be created from different places and the query to generate the report is complex it’s been packed into a stored procedure that accepts three parameters: @startDate – The beginning of the date range for which the report should be run. @endDate – The end of the date range for which the report should be run. @customerIds – The customer Ids for which the report should be run. Obviously, the @startDate and @endDate parameters are DATETIME variables. The @customerIds parameter, however, needs to contain a list of the identity values (primary key) from the Customers table representing the customers that were selected for this particular run of the report. In prior versions of SQL Server we might have made this parameter a VARCHAR variable, but with SQL Server 2008 we can make it into a table-valued parameter. Defining And Using The Table Type In order to use a table-valued parameter, we first need to tell SQL Server about what the table will look like. We do this by creating a user defined type. For the purposes of this stored procedure we need a very simple type to model a table variable with a single integer column. We can create a generic type called ‘IntegerListTableType’ like this: CREATE TYPE IntegerListTableType AS TABLE (Value INT NOT NULL) Once defined, we can use this new type to define the @customerIds parameter in the signature of our stored procedure. The parameter list for the stored procedure definition might look like: 1: CREATE PROCEDURE dbo.rpt_CustomerTransactionSummary 2: @starDate datetime, 3: @endDate datetime, 4: @customerIds IntegerListTableTableType READONLY   Note the ‘READONLY’ statement following the declaration of the @customerIds parameter. SQL Server requires any table-valued parameter be marked as ‘READONLY’ and no DML (INSERT/UPDATE/DELETE) statements can be performed on a table-valued parameter within the routine in which it’s used. Aside from the DML restriction, however, you can do pretty much anything with a table-valued parameter as you could with a normal TABLE variable. With the user defined type and stored procedure defined as above, we could invoke like this: 1: DECLARE @cusomterIdList IntegerListTableType 2: INSERT @customerIdList VALUES (1) 3: INSERT @customerIdList VALUES (2) 4: INSERT @customerIdList VALUES (3) 5:  6: EXEC dbo.rpt_CustomerTransationSummary 7: @startDate = '2012-05-01', 8: @endDate = '2012-06-01' 9: @customerIds = @customerIdList   Note that we can simply declare a variable of type ‘IntegerListTableType’ just like any other normal variable and insert values into it just like a TABLE variable. We could also populate the variable with a SELECT … INTO or INSERT … SELECT statement if desired. Using The Table-Valued Parameter With ADO .NET Invoking a stored procedure with a table-valued parameter from ADO .NET is as simple as building a DataTable and passing it in as the Value of a SqlParameter. Here’s some example code for how we would construct the SqlParameter for the @customerIds parameter in our stored procedure: 1: var customerIdsParameter = new SqlParameter(); 2: customerIdParameter.Direction = ParameterDirection.Input; 3: customerIdParameter.TypeName = "IntegerListTableType"; 4: customerIdParameter.Value = selectedCustomerIds.ToIntegerListDataTable("Value");   All we’re doing here is new’ing up an instance of SqlParameter, setting the pamameters direction, specifying the name of the User Defined Type that this parameter uses, and setting its value. We’re assuming here that we have an IEnumerable<int> variable called ‘selectedCustomerIds’ containing all of the customer Ids for which the report should be run. The ‘ToIntegerListDataTable’ method is an extension method of the IEnumerable<int> type that looks like this: 1: public static DataTable ToIntegerListDataTable(this IEnumerable<int> intValues, string columnName) 2: { 3: var intergerListDataTable = new DataTable(); 4: intergerListDataTable.Columns.Add(columnName); 5: foreach(var intValue in intValues) 6: { 7: var nextRow = intergerListDataTable.NewRow(); 8: nextRow[columnName] = intValue; 9: intergerListDataTable.Rows.Add(nextRow); 10: } 11:  12: return intergerListDataTable; 13: }   Since the ‘IntegerListTableType’ has a single int column called ‘Value’, we pass that in for the ‘columnName’ parameter to the extension method. The method creates a new single-columned DataTable using the provided column name then iterates over the items in the IEnumerable<int> instance adding one row for each value. We can then use this SqlParameter instance when invoking the stored procedure just like we would use any other parameter. Advanced Functionality Using passing a list of integers into a stored procedure is a very simple usage scenario for the table-valued parameters feature, but I’ve found that it covers the majority of situations where I’ve needed to pass a collection of data for use in a query at run-time. I should note that BULK INSERT feature still makes sense for passing large amounts of data to SQL Server for processing. MSDN seems to suggest that 1000 rows of data is the tipping point where the overhead of a BULK INSERT operation can pay dividends. I should also note here that table-valued parameters can be used to deal with more complex data structures than single-columned tables of integers. A User Defined Type that backs a table-valued parameter can use things like identities and computed columns. That said, using some of these more advanced features might require the use the SqlDataRecord and SqlMetaData classes instead of a simple DataTable. Erland Sommarskog has a great article on his website that describes when and how to use these classes for table-valued parameters. What About Reporting Services? Earlier in the post I referenced the fact that our example stored procedure would be called from both a web application and a SQL Server Reporting Services report. Unfortunately, using table-valued parameters from SSRS reports can be a bit tricky and warrants its own blog post which I’ll be putting together and posting sometime in the near future.

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  • SQL Server Split() Function

    - by HighAltitudeCoder
    Title goes here   Ever wanted a dbo.Split() function, but not had the time to debug it completely?  Let me guess - you are probably working on a stored procedure with 50 or more parameters; two or three of them are parameters of differing types, while the other 47 or so all of the same type (id1, id2, id3, id4, id5...).  Worse, you've found several other similar stored procedures with the ONLY DIFFERENCE being the number of like parameters taped to the end of the parameter list. If this is the situation you find yourself in now, you may be wondering, "why am I working with three different copies of what is basically the same stored procedure, and why am I having to maintain changes in three different places?  Can't I have one stored procedure that accomplishes the job of all three? My answer to you: YES!  Here is the Split() function I've created.    /******************************************************************************                                       Split.sql   ******************************************************************************/ /******************************************************************************   Split a delimited string into sub-components and return them as a table.   Parameter 1: Input string which is to be split into parts. Parameter 2: Delimiter which determines the split points in input string. Works with space or spaces as delimiter. Split() is apostrophe-safe.   SYNTAX: SELECT * FROM Split('Dvorak,Debussy,Chopin,Holst', ',') SELECT * FROM Split('Denver|Seattle|San Diego|New York', '|') SELECT * FROM Split('Denver is the super-awesomest city of them all.', ' ')   ******************************************************************************/ USE AdventureWorks GO   IF EXISTS       (SELECT *       FROM sysobjects       WHERE xtype = 'TF'       AND name = 'Split'       ) BEGIN       DROP FUNCTION Split END GO   CREATE FUNCTION Split (       @InputString                  VARCHAR(8000),       @Delimiter                    VARCHAR(50) )   RETURNS @Items TABLE (       Item                          VARCHAR(8000) )   AS BEGIN       IF @Delimiter = ' '       BEGIN             SET @Delimiter = ','             SET @InputString = REPLACE(@InputString, ' ', @Delimiter)       END         IF (@Delimiter IS NULL OR @Delimiter = '')             SET @Delimiter = ','   --INSERT INTO @Items VALUES (@Delimiter) -- Diagnostic --INSERT INTO @Items VALUES (@InputString) -- Diagnostic         DECLARE @Item                 VARCHAR(8000)       DECLARE @ItemList       VARCHAR(8000)       DECLARE @DelimIndex     INT         SET @ItemList = @InputString       SET @DelimIndex = CHARINDEX(@Delimiter, @ItemList, 0)       WHILE (@DelimIndex != 0)       BEGIN             SET @Item = SUBSTRING(@ItemList, 0, @DelimIndex)             INSERT INTO @Items VALUES (@Item)               -- Set @ItemList = @ItemList minus one less item             SET @ItemList = SUBSTRING(@ItemList, @DelimIndex+1, LEN(@ItemList)-@DelimIndex)             SET @DelimIndex = CHARINDEX(@Delimiter, @ItemList, 0)       END -- End WHILE         IF @Item IS NOT NULL -- At least one delimiter was encountered in @InputString       BEGIN             SET @Item = @ItemList             INSERT INTO @Items VALUES (@Item)       END         -- No delimiters were encountered in @InputString, so just return @InputString       ELSE INSERT INTO @Items VALUES (@InputString)         RETURN   END -- End Function GO   ---- Set Permissions --GRANT SELECT ON Split TO UserRole1 --GRANT SELECT ON Split TO UserRole2 --GO   The syntax is basically as follows: SELECT <fields> FROM Table 1 JOIN Table 2 ON ... JOIN Table 3 ON ... WHERE LOGICAL CONDITION A AND LOGICAL CONDITION B AND LOGICAL CONDITION C AND TABLE2.Id IN (SELECT * FROM Split(@IdList, ',')) @IdList is a parameter passed into the stored procedure, and the comma (',') is the delimiter you have chosen to split the parameter list on. You can also use it like this: SELECT <fields> FROM Table 1 JOIN Table 2 ON ... JOIN Table 3 ON ... WHERE LOGICAL CONDITION A AND LOGICAL CONDITION B AND LOGICAL CONDITION C HAVING COUNT(SELECT * FROM Split(@IdList, ',') Similarly, it can be used in other aggregate functions at run-time: SELECT MIN(SELECT * FROM Split(@IdList, ','), <fields> FROM Table 1 JOIN Table 2 ON ... JOIN Table 3 ON ... WHERE LOGICAL CONDITION A AND LOGICAL CONDITION B AND LOGICAL CONDITION C GROUP BY <fields> Now that I've (hopefully effectively) explained the benefits to using this function and implementing it in one or more of your database objects, let me warn you of a caveat that you are likely to encounter.  You may have a team member who waits until the right moment to ask you a pointed question: "Doesn't this function just do the same thing as using the IN function?  Why didn't you just use that instead?  In other words, why bother with this function?" What's happening is, one or more team members has failed to understand the reason for implementing this kind of function in the first place.  (Note: this is THE MOST IMPORTANT ASPECT OF THIS POST). Allow me to outline a few pros to implementing this function, so you may effectively parry this question.  Touche. 1) Code consolidation.  You don't have to maintain what is basically the same code and logic, but with varying numbers of the same parameter in several SQL objects.  I'm not going to go into the cons related to using this function, because the afore mentioned team member is probably more than adept at pointing these out.  Remember, the real positive contribution is ou are decreasing the liklihood that your team fails to update all (x) duplicate copies of what are basically the same stored procedure, and so on...  This is the classic downside to duplicate code.  It is a virus, and you should kill it. You might be better off rejecting your team member's question, and responding with your own: "Would you rather maintain the same logic in multiple different stored procedures, and hope that the team doesn't forget to always update all of them at the same time?".  In his head, he might be thinking "yes, I would like to maintain several different copies of the same stored procedure", although you probably will not get such a direct response.  2) Added flexibility - you can use the Split function elsewhere, and for splitting your data in different ways.  Plus, you can use any kind of delimiter you wish.  How can you know today the ways in which you might want to examine your data tomorrow?  Segue to my next point. 3) Because the function takes a delimiter parameter, you can split the data in any number of ways.  This greatly increases the utility of such a function and enables your team to work with the data in a variety of different ways in the future.  You can split on a single char, symbol, word, or group of words.  You can split on spaces.  (The list goes on... test it out). Finally, you can dynamically define the behavior of a stored procedure (or other SQL object) at run time, through the use of this function.  Rather than have several objects that accomplish almost the same thing, why not have only one instead?

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  • Fun with Aggregates

    - by Paul White
    There are interesting things to be learned from even the simplest queries.  For example, imagine you are given the task of writing a query to list AdventureWorks product names where the product has at least one entry in the transaction history table, but fewer than ten. One possible query to meet that specification is: SELECT p.Name FROM Production.Product AS p JOIN Production.TransactionHistory AS th ON p.ProductID = th.ProductID GROUP BY p.ProductID, p.Name HAVING COUNT_BIG(*) < 10; That query correctly returns 23 rows (execution plan and data sample shown below): The execution plan looks a bit different from the written form of the query: the base tables are accessed in reverse order, and the aggregation is performed before the join.  The general idea is to read all rows from the history table, compute the count of rows grouped by ProductID, merge join the results to the Product table on ProductID, and finally filter to only return rows where the count is less than ten. This ‘fully-optimized’ plan has an estimated cost of around 0.33 units.  The reason for the quote marks there is that this plan is not quite as optimal as it could be – surely it would make sense to push the Filter down past the join too?  To answer that, let’s look at some other ways to formulate this query.  This being SQL, there are any number of ways to write logically-equivalent query specifications, so we’ll just look at a couple of interesting ones.  The first query is an attempt to reverse-engineer T-SQL from the optimized query plan shown above.  It joins the result of pre-aggregating the history table to the Product table before filtering: SELECT p.Name FROM ( SELECT th.ProductID, cnt = COUNT_BIG(*) FROM Production.TransactionHistory AS th GROUP BY th.ProductID ) AS q1 JOIN Production.Product AS p ON p.ProductID = q1.ProductID WHERE q1.cnt < 10; Perhaps a little surprisingly, we get a slightly different execution plan: The results are the same (23 rows) but this time the Filter is pushed below the join!  The optimizer chooses nested loops for the join, because the cardinality estimate for rows passing the Filter is a bit low (estimate 1 versus 23 actual), though you can force a merge join with a hint and the Filter still appears below the join.  In yet another variation, the < 10 predicate can be ‘manually pushed’ by specifying it in a HAVING clause in the “q1” sub-query instead of in the WHERE clause as written above. The reason this predicate can be pushed past the join in this query form, but not in the original formulation is simply an optimizer limitation – it does make efforts (primarily during the simplification phase) to encourage logically-equivalent query specifications to produce the same execution plan, but the implementation is not completely comprehensive. Moving on to a second example, the following query specification results from phrasing the requirement as “list the products where there exists fewer than ten correlated rows in the history table”: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) < 10 ); Unfortunately, this query produces an incorrect result (86 rows): The problem is that it lists products with no history rows, though the reasons are interesting.  The COUNT_BIG(*) in the EXISTS clause is a scalar aggregate (meaning there is no GROUP BY clause) and scalar aggregates always produce a value, even when the input is an empty set.  In the case of the COUNT aggregate, the result of aggregating the empty set is zero (the other standard aggregates produce a NULL).  To make the point really clear, let’s look at product 709, which happens to be one for which no history rows exist: -- Scalar aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709;   -- Vector aggregate SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = 709 GROUP BY th.ProductID; The estimated execution plans for these two statements are almost identical: You might expect the Stream Aggregate to have a Group By for the second statement, but this is not the case.  The query includes an equality comparison to a constant value (709), so all qualified rows are guaranteed to have the same value for ProductID and the Group By is optimized away. In fact there are some minor differences between the two plans (the first is auto-parameterized and qualifies for trivial plan, whereas the second is not auto-parameterized and requires cost-based optimization), but there is nothing to indicate that one is a scalar aggregate and the other is a vector aggregate.  This is something I would like to see exposed in show plan so I suggested it on Connect.  Anyway, the results of running the two queries show the difference at runtime: The scalar aggregate (no GROUP BY) returns a result of zero, whereas the vector aggregate (with a GROUP BY clause) returns nothing at all.  Returning to our EXISTS query, we could ‘fix’ it by changing the HAVING clause to reject rows where the scalar aggregate returns zero: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID HAVING COUNT_BIG(*) BETWEEN 1 AND 9 ); The query now returns the correct 23 rows: Unfortunately, the execution plan is less efficient now – it has an estimated cost of 0.78 compared to 0.33 for the earlier plans.  Let’s try adding a redundant GROUP BY instead of changing the HAVING clause: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY th.ProductID HAVING COUNT_BIG(*) < 10 ); Not only do we now get correct results (23 rows), this is the execution plan: I like to compare that plan to quantum physics: if you don’t find it shocking, you haven’t understood it properly :)  The simple addition of a redundant GROUP BY has resulted in the EXISTS form of the query being transformed into exactly the same optimal plan we found earlier.  What’s more, in SQL Server 2008 and later, we can replace the odd-looking GROUP BY with an explicit GROUP BY on the empty set: SELECT p.Name FROM Production.Product AS p WHERE EXISTS ( SELECT * FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ); I offer that as an alternative because some people find it more intuitive (and it perhaps has more geek value too).  Whichever way you prefer, it’s rather satisfying to note that the result of the sub-query does not exist for a particular correlated value where a vector aggregate is used (the scalar COUNT aggregate always returns a value, even if zero, so it always ‘EXISTS’ regardless which ProductID is logically being evaluated). The following query forms also produce the optimal plan and correct results, so long as a vector aggregate is used (you can probably find more equivalent query forms): WHERE Clause SELECT p.Name FROM Production.Product AS p WHERE ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) < 10; APPLY SELECT p.Name FROM Production.Product AS p CROSS APPLY ( SELECT NULL FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () HAVING COUNT_BIG(*) < 10 ) AS ca (dummy); FROM Clause SELECT q1.Name FROM ( SELECT p.Name, cnt = ( SELECT COUNT_BIG(*) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID GROUP BY () ) FROM Production.Product AS p ) AS q1 WHERE q1.cnt < 10; This last example uses SUM(1) instead of COUNT and does not require a vector aggregate…you should be able to work out why :) SELECT q.Name FROM ( SELECT p.Name, cnt = ( SELECT SUM(1) FROM Production.TransactionHistory AS th WHERE th.ProductID = p.ProductID ) FROM Production.Product AS p ) AS q WHERE q.cnt < 10; The semantics of SQL aggregates are rather odd in places.  It definitely pays to get to know the rules, and to be careful to check whether your queries are using scalar or vector aggregates.  As we have seen, query plans do not show in which ‘mode’ an aggregate is running and getting it wrong can cause poor performance, wrong results, or both. © 2012 Paul White Twitter: @SQL_Kiwi email: [email protected]

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