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  • Set up lnux box for hosting a-z [apache mysql php ssl]

    - by microchasm
    I am in the process of reinstalling the OS on a machine that will be used to host a couple of apps for our business. The apps will be local only; access from external clients will be via vpn only. The prior setup used a hosting control panel (Plesk) for most of the admin, and I was looking at using another similar piece of software for the reinstall - but I figured I should finally learn how it all works. I can do most of the things the software would do for me, but am unclear on the symbiosis of it all. This is all an attempt to further distance myself from the land of Configuration Programmer/Programmer, if at all possible. I can't find a full walkthrough anywhere for what I'm looking for, so I thought I'd put up this question, and if people can help me on the way I will edit this with the answers, and document my progress/pitfalls. Hopefully someday this will help someone down the line. The details: CentOS 5.5 x86_64 httpd: Apache/2.2.3 mysql: 5.0.77 (to be upgraded) php: 5.1 (to be upgraded) The requirements: SECURITY!! Secure file transfer Secure client access (SSL Certs and CA) Secure data storage Virtualhosts/multiple subdomains Local email would be nice, but not critical The Steps: Download latest CentOS DVD-iso (torrent worked great for me). Install CentOS: While going through the install, I checked the Server Components option thinking I was going to be using another Plesk-like admin. In hindsight, considering I've decided to try to go my own way, this probably wasn't the best idea. Basic config: Setup users, networking/ip address etc. Yum update/upgrade. Upgrade PHP: To upgrade PHP to the latest version, I had to look to another repo outside CentOS. IUS looks great and I'm happy I found it! cd /tmp #wget http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/epel-release-1-1.ius.el5.noarch.rpm #rpm -Uvh epel-release-1-1.ius.el5.noarch.rpm #wget http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/ius-release-1-4.ius.el5.noarch.rpm #rpm -Uvh ius-release-1-4.ius.el5.noarch.rpm yum list | grep -w \.ius\. [will list all packages available in the IUS repo] rpm -qa | grep php [will list installed packages needed to be removed. the installed packages need to be removed before you can install the IUS packages otherwise there will be conflicts] #yum shell >remove php-gd php-cli php-odbc php-mbstring php-pdo php php-xml php-common php-ldap php-mysql php-imap Setting up Remove Process >install php53 php53-mcrypt php53-mysql php53-cli php53-common php53-ldap php53-imap php53-devel >transaction solve >transaction run Leaving Shell #php -v PHP 5.3.2 (cli) (built: Apr 6 2010 18:13:45) This process removes the old version of PHP and installs the latest. To upgrade mysql: Pretty much the same process as above with PHP #/etc/init.d/mysqld stop [OK] rpm -qa | grep mysql [installed mysql packages] #yum shell >remove mysql mysql-server Setting up Remove Process >install mysql51 mysql51-server mysql51-devel >transaction solve >transaction run Leaving Shell #service mysqld start [OK] #mysql -v Server version: 5.1.42-ius Distributed by The IUS Community Project And this is where I'm at. I will keep editing this as I make progress. Any tips on how to Configure Virtualhosts for SSL, setting up a CA, setting up SFTP with openSSH, or anything else would be appreciated.

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  • "The server closed the connection without sending any data"

    - by Toby
    Server setup The problem Diagnostic information What I've tried Specific Help needed 1. I have the following server setup: Debian Squeeze Linux 2.6.32-5-amd64 Apache2-mpm-prefork 2.2.16-6+squeeze10 PHP 5.3.3-7+squeeze14 This server is protected with the Suhosin Patch 0.9.9.1 Max Requests Per Child: 0 - Keep Alive: on - Max Per Connection: 100 Timeouts Connection: 300 - Keep-Alive: 15 Loaded Modules core mod_log_config mod_logio prefork http_core mod_so mod_alias mod_auth_basic mod_auth_digest mod_authn_file mod_authz_default mod_authz_groupfile mod_authz_host mod_authz_user mod_cgi mod_deflate mod_dir mod_env mod_mime mod_negotiation mod_php5 mod_reqtimeout mod_rewrite mod_setenvif mod_ssl mod_status Wordpress 3.4.2 (Upgrading to 3.5 soon :) 2. The problem When I restart the server (sudo shutdown -r now), going to any website page results in the following error from the web browser (in this case, Google Chrome, but other browsers also show the same error). This error can also occur an hour or so after all is working ok, seemingly randomly, which is my biggest concern as it means my server is not reliable: No data received Unable to load the web page because the server sent no data. Here are some suggestions: Reload this web page later. Error 324 (net::ERR_EMPTY_RESPONSE): The server closed the connection without sending any data. 3. Diagnostic information The apache error log contains the folowing entries: [Fri Dec 14 22:23:27 2012] [notice] child pid 1955 exit signal Floating point exception (8) [Fri Dec 14 22:23:27 2012] [notice] child pid 1956 exit signal Floating point exception (8) [Fri Dec 14 22:23:29 2012] [notice] child pid 1957 exit signal Floating point exception (8) [Fri Dec 14 22:23:30 2012] [notice] child pid 1958 exit signal Floating point exception (8) [Fri Dec 14 22:23:32 2012] [notice] child pid 1959 exit signal Floating point exception (8) [Fri Dec 14 22:23:32 2012] [notice] child pid 1960 exit signal Floating point exception (8) [Fri Dec 14 22:23:34 2012] [notice] child pid 1961 exit signal Floating point exception (8) [Fri Dec 14 22:23:34 2012] [notice] child pid 1962 exit signal Floating point exception (8) 4. What I've tried a) I can 'fix' the website temporarily by resetting the server twice (resetting it once does not work) using the following commands. NB: the 'reload' option does not work, I have to use restart twice. However, the error can reoccur sometime later. sudo /etc/init.d/apache2 restart sudo /etc/init.d/apache2 restart b) I have tried disabling suhosin by uninstalling php5-suhosin, but a php info page still shows "This server is protected with the Suhosin Patch 0.9.9.1". I have tried putting Suhosin into simulation mode by creating a file /etc/php5/apache2/conf.d/suhosin.ini containing: [suhosin] suhosin.simulation = On The php info page shows the suhosin.ini file in the list of "Additional .ini files parsed" but the php info page still shows "This server is protected with the Suhosin Patch 0.9.9.1" c) Increasing the PHP memory limit In /etc/php5/apache2/ : ; Maximum amount of memory a script may consume (128MB) ; http://php.net/memory-limit memory_limit = 512M d) Disabling all Wordpress plugins, and going back to the default theme. 5. Specific help needed I would very much like help in debugging what is going on here. I am not sure how to determine what processes are in the Apache error log which are exiting "[notice] child pid 1955 exit signal Floating point exception (8)", or what is causing them to exit. And whether suhosin is part of the problem (and how to disable it if it is). Thank you in advance for any advice or tips you can offer in helping me debug this.

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  • Mysqld not starting due to apparent db corruption

    - by pitosalas
    I am very new at admining mysql, and bad for me, something caused the db to get clobbered. There are many error messages in the log that I am not sure how to safely proceed. Can you give some tips? Here's the log: 110107 15:07:15 mysqld started 110107 15:07:15 InnoDB: Database was not shut down normally! InnoDB: Starting crash recovery. InnoDB: Reading tablespace information from the .ibd files... InnoDB: Restoring possible half-written data pages from the doublewrite InnoDB: buffer... 110107 15:07:15 InnoDB: Starting log scan based on checkpoint at InnoDB: log sequence number 35 515914826. InnoDB: Doing recovery: scanned up to log sequence number 35 515915839 InnoDB: 1 transaction(s) which must be rolled back or cleaned up InnoDB: in total 1 row operations to undo InnoDB: Trx id counter is 0 1697553664 110107 15:07:15 InnoDB: Starting an apply batch of log records to the database... InnoDB: Progress in percents: 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 InnoDB: Apply batch completed InnoDB: Starting rollback of uncommitted transactions InnoDB: Rolling back trx with id 0 1697553198, 1 rows to undoInnoDB: Error: trying to access page number 3522914176 in space 0, InnoDB: space name ./ibdata1, InnoDB: which is outside the tablespace bounds. InnoDB: Byte offset 0, len 16384, i/o type 10 110107 15:07:15InnoDB: Assertion failure in thread 3086403264 in file fil0fil.c line 3922 InnoDB: We intentionally generate a memory trap. InnoDB: Submit a detailed bug report to http://bugs.mysql.com. InnoDB: If you get repeated assertion failures or crashes, even InnoDB: immediately after the mysqld startup, there may be InnoDB: corruption in the InnoDB tablespace. Please refer to InnoDB: http://dev.mysql.com/doc/mysql/en/Forcing_recovery.html InnoDB: about forcing recovery. mysqld got signal 11; This could be because you hit a bug. It is also possible that this binary or one of the libraries it was linked against is corrupt, improperly built, or misconfigured. This error can also be caused by malfunctioning hardware. We will try our best to scrape up some info that will hopefully help diagnose the problem, but since we have already crashed, something is definitely wrong and this may fail. key_buffer_size=0 read_buffer_size=131072 max_used_connections=0 max_connections=100 threads_connected=0 It is possible that mysqld could use up to key_buffer_size + (read_buffer_size + sort_buffer_size)*max_connections = 217599 K bytes of memory Hope that's ok; if not, decrease some variables in the equation. thd=(nil) Attempting backtrace. You can use the following information to find out where mysqld died. If you see no messages after this, something went terribly wrong... Cannot determine thread, fp=0xbffc55ac, backtrace may not be correct. Stack range sanity check OK, backtrace follows: 0x8139eec 0x83721d5 0x833d897 0x833db71 0x832aa38 0x835f025 0x835f7a3 0x830a77e 0x8326b57 0x831c825 0x8317b8d 0x82a9e66 0x8315732 0x834fc9a 0x828d7c3 0x81c29dd 0x81b5620 0x813d9fe 0x40fdf3 0x80d5ff1 New value of fp=(nil) failed sanity check, terminating stack trace! Please read http://dev.mysql.com/doc/mysql/en/Using_stack_trace.html and follow instructions on how to resolve the stack trace. Resolved stack trace is much more helpful in diagnosing the problem, so please do resolve it The manual page at http://www.mysql.com/doc/en/Crashing.html contains information that should help you find out what is causing the crash. 110107 15:07:15 mysqld ended

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  • nhibernate mapping: A collection with cascade="all-delete-orphan" was no longer referenced

    - by Chev
    Hi All I am having some probs with my fluent mappings. I have an entity with a child collection of entities i.e Event and EventItems for example. If I set my cascade mapping of the collection to AllDeleteOrphan I get the following error when saving a new entity to the DB: NHibernate.HibernateException : A collection with cascade="all-delete-orphan" was no longer referenced by the owning entity instance: Core.Event.EventItems If I set the cascade to All it works fine? Below are my classes and mapping files: public class EventMap : ClassMap<Event> { public EventMap() { Id(x => x.Id, "Id") .UnsavedValue("00000000-0000-0000-0000-000000000000") .GeneratedBy.GuidComb(); Map(x => x.Name); HasMany(x => x.EventItems) .Inverse() .KeyColumn("EventId") .AsBag() .Cascade.AllDeleteOrphan(); } } public class EventItemMap : SubclassMap<EventItem> { public EventItemMap() { Id(x => x.Id, "Id") .UnsavedValue("00000000-0000-0000-0000-000000000000") .GeneratedBy.GuidComb(); References(x => x.Event, "EventId"); } } public class Event : EntityBase { private IList<EventItem> _EventItems; protected Event() { InitMembers(); } public Event(string name) : this() { Name = name; } private void InitMembers() { _EventItems = new List<EventItem>(); } public virtual EventItem CreateEventItem(string name) { EventItem eventItem = new EventItem(this, name); _EventItems.Add(eventItem); return eventItem; } public virtual string Name { get; private set; } public virtual IList<EventItem> EventItems { get { return _EventItems.ToList<EventItem>().AsReadOnly(); } protected set { _EventItems = value; } } } public class EventItem : EntityBase { protected EventItem() { } public EventItem(Event @event, string name):base(name) { Event = @event; } public virtual Event Event { get; private set; } } Pretty stumped here. Any tips greatly appreciated. Chev

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  • WPF CommandParameter is NULL first time CanExecute is called

    - by Jonas Follesø
    I have run into an issue with WPF and Commands that are bound to a Button inside the DataTemplate of an ItemsControl. The scenario is quite straight forward. The ItemsControl is bound to a list of objects, and I want to be able to remove each object in the list by clicking a Button. The Button executes a Command, and the Command takes care of the deletion. The CommandParameter is bound to the Object I want to delete. That way I know what the user clicked. A user should only be able to delete their "own" objects - so I need to do some checks in the "CanExecute" call of the Command to verify that the user has the right permissions. The problem is that the parameter passed to CanExecute is NULL the first time it's called - so I can't run the logic to enable/disable the command. However, if I make it allways enabled, and then click the button to execute the command, the CommandParameter is passed in correctly. So that means that the binding against the CommandParameter is working. The XAML for the ItemsControl and the DataTemplate looks like this: <ItemsControl x:Name="commentsList" ItemsSource="{Binding Path=SharedDataItemPM.Comments}" Width="Auto" Height="Auto"> <ItemsControl.ItemTemplate> <DataTemplate> <StackPanel Orientation="Horizontal"> <Button Content="Delete" FontSize="10" Command="{Binding Path=DataContext.DeleteCommentCommand, ElementName=commentsList}" CommandParameter="{Binding}" /> </StackPanel> </DataTemplate> </ItemsControl.ItemTemplate> </ItemsControl> So as you can see I have a list of Comments objects. I want the CommandParameter of the DeleteCommentCommand to be bound to the Command object. So I guess my question is: have anyone experienced this problem before? CanExecute gets called on my Command, but the parameter is always NULL the first time - why is that? Update: I was able to narrow the problem down a little. I added an empty Debug ValueConverter so that I could output a message when the CommandParameter is data bound. Turns out the problem is that the CanExecute method is executed before the CommandParameter is bound to the button. I have tried to set the CommandParameter before the Command (like suggested) - but it still doesn't work. Any tips on how to control it. Update2: Is there any way to detect when the binding is "done", so that I can force re-evaluation of the command? Also - is it a problem that I have multiple Buttons (one for each item in the ItemsControl) that bind to the same instance of a Command-object? Update3: I have uploaded a reproduction of the bug to my SkyDrive: http://cid-1a08c11c407c0d8e.skydrive.live.com/self.aspx/Code%20samples/CommandParameterBinding.zip

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  • Dissertation about website and database security - in need of some pointers

    - by ClarkeyBoy
    Hi, I am on my dissertation in my final year at university at the moment. One of the areas I need to research is security - for both websites and for databases. I currently have sections on the following: Website Form security - such as data validation. This section is more about preventing errors made by legitimate users as much as possible rather than stopping hackers, for example comparing a field to a regular expression and giving them meaningful feedback on any errors which did occur so as to stop it happening again. Constraints. For example if a value must be true or false then use a checkbox. If it is likely to be one of several values then use a dropdown or a set of radio boxes, and so on. If the value is unpredictable then use regular expressions to limit what characters they are allowed to enter, and to restrict the length of the string, and sometimes to limit the format (such as for dates / times, post codes and so on). Sometimes you can limit permissions to the form. This is on the occasion that you know exactly who (whether it be peoples names or a group of people - such as administrators or employees) is going to need access to the form. Restricting permissions will stop members of the public from being able to access the form. Symbols or strings which could be used maliciously or cause the website to act incorrectly (such as the script tag) should be filtered out or html encoded. Captcha images can be used to prevent automated systems from filling in and submitting the form. There are some hacks for file uploads - such as using double extensions - which can allow hackers to upload malicious files. Databases (this is nowhere near done yet but the sections I have planned are listed below) SQL statements vs stored procedures Throwing an error when one of the variables contains particular characters or groups of characters (I cant remember what characters they are, but I have seen a message thrown back at me before where I have tried to enter html or something into a text area). SQL Injection - and ways around it, with some examples. Does anyone have any hints and tips on where I could go for some decent, reliable information either about these areas or about other areas of security that I could cover? Thanks in advance. Regards, Richard PS I am a complete newbie when it comes to security, so please be patient with me. If any of the information I have put down is wrong or could be sub-sectioned then please feel free to say so.

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  • CSS3 Gradients to reproduce an 'inner glow' effect from Illustrator with border-radius applied

    - by iamfriendly
    Hello all! First post on here so please be kind :) I am in the process of trying to get my head properly around CSS3 Gradients (specifically radial ones) and in doing so I think I've set myself a relatively tough challenge. In Adobe Illustrator I have created a 'button' style which can be seen here: http://bit.ly/aePPtV (jpg image). To create this image I created a rectangle with a background colour of rgb(63,64,63) or #3F403F, then 'stylized' it to have a 15px border radius. I then applied an 'inner glow' to it with a 25% opacity, 8px blur, white from the center. Finally, I applied a 3pt white stroke on it. (I'm telling you all of this in case you wished to reproduce it, if the image above isn't sufficient.) So, my question is thus: is it possible to recreate this 'button' using CSS without the need for an image? I am aware of the 'limitations' of Internet Explorer (and for the sake of this experiment, I couldn't give a monkeys). I am also aware of the small 'bug' in webkit which incorrectly renders an element with a background colour, border-radius and a border (with a different color to the background-color) - it lets the background color bleed through on the curved corners. My best attempt so far is fairly pathetic, but for reference here is the code: section#featured footer p a { color: rgb(255,255,255); text-shadow: 1px 1px 1px rgba(0,0,0,0.6); text-decoration: none; padding: 5px 10px; border-radius: 15px; -moz-border-radius: 15px; -webkit-border-radius: 15px; border: 3px solid rgb(255,255,255); background: rgb(98,99,100); background: -moz-radial-gradient( 50% 50%, farthest-side, #626364, #545454 ); background: -webkit-gradient( radial, 50% 50%, 1px, 50% 50%, 5px, from(rgb(98,99,100)), to(rgb(84,84,84)) ); } Basically, terrible. Any hints or tips gratefully accepted and thank you very much in advance for them!

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  • Rendering a WPF Network Map/Graph layout - Manual? PathListBox? Something Else?

    - by Ben Von Handorf
    I'm writing code to present the user with a simplified network map. At any given time, the map is focused on a specific item... say a router or a server. Based on the focused item, other network entities are grouped into sets (i.e. subnets or domains) and then rendered around the focused item. Lines would represent connections and groups would be visually grouped inside a rectangle or ellipse. Panning and zooming are required features. An item can be selected to display more information in a "properties" style window. An item could also be double-clicked to re-focus the entire network map on that item. At that point, the entire map would be re-calculated. I am using MVVM without any framework, as of yet. Assume the logic for grouping items and determining what should be shown or not is all in place. I'm looking for the best way to approach the UI layout. So far, I'm aware of the following options: Use a canvas for layout (inside a ScrollViewer to handle the panning). Have my ViewModel make use of a Layout Manager type of class, which would handle assigning all the layout properties (Top, Left, etc.). Bind my set of display items to an ItemsControl and use Data Templates to handle the actual rendering. The drawbacks with this approach: Highly manual layout on my part. Lots of calculation. I have to handle item selection manually. Computation of connecting lines is manual. The Pros of this approach: I can draw additional lines between child subnets as appropriate (manually). Additional LayoutManagers could be added later to render the display differently. This could probably be wrapped up into some sort of a GraphLayout control to be re-used. Present the focused item at the center of the display and then use a PathListBox for layout of the additional items. Have my ViewModel expose a simple list of things to be drawn and bind them to the PathListBox. Override the ListBoxItem Template to also create a line geometry from the borders of the focused item (tricky) to the bound item. Use DataTemplates to handle the case where the item being bound is a subnet, in which case we would use another PathListBox in the template to display items inside the subnet. The drawbacks with this approach: Selected Item synchronization across multiple `PathListBox`es. Only one item on the whole graph can be selected at a time, but each child PathListBox maintains its own selection. Also, subnets cannot be selected, but would be selectable without additional work. Drawing the connecting lines is going to be a bit of trickery in the ListBoxItem template, since I need to know the correct side of the focused item to connect to. The pros of this approach: I get to stay out of the layout business, more. I'm looking for any advice or thoughts from others who have encountered similar issues or who have more WPF experience than I. I'm using WPF 4, so any new tricks are legal and encouraged.

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  • struts2 invalid.token returned when form submitted using JQuery

    - by John
    Hi, I have inherited some code in which I now have to add CSRF prevention and am trying to use the struts2 tokenSession interceptor to do this. I am adding a token to my form using the struts2 token tag like so: <form id="updateObject" name="updateObject" action="<%=request.getContextPath()%>/prv/updateObject.action" method="POST"> <fieldset class="x-fieldset"> <legend>Update object - Action Required</legend> <div>...</div> <s:token /> <s:hidden name="id" id="objectId" /> more stuff here... <input type="submit" value="Update Object" onclick="javascript:return doUpdateObject('myAction');"/> </fieldset> </form> In my javascript function, I am adding/removing some validation rules (depending upon the action required, and submitting the form: function doUpdateObject(action){ actionPanel.registerAction(action); // this function places the action name in an in-scope variable doUpdateObjectValidationSetup(action); // this function adds/removes jquery validation rules depending upon the action if($("#updateObject").valid()){ $("form#updateObject").submit(); } return false; } I have intercepted the request and a token is being added, however the struts2 tokenSession interceptor is returning invalid.token. The code works as expected without this interceptor. (struts2 xml file not posted - will post the relevant section if required). I have also used the tokenSession interceptor in other pages which use a basic html submit button (i.e. not going via javascript or jquery) and this also works as expected. What is making the token invalid? N.B. The project I have inherited uses a strange mixture of standard html, struts2 tags, ExtJS and JQuery. I will clean this up at some point but at the moment I just need to get the tokenSession interceptor working asap in the code as-is (as I have to apply a similar fix to several hundred pages...). Any help/pointers/tips/etc greatly appreciated! Regards, John

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  • ASP.NET MVC2: Getting textbox data from a view to a controller

    - by mr_plumley
    Hi, I'm having difficulty getting data from a textbox into a Controller. I've read about a few ways to accomplish this in Sanderson's book, Pro ASP.NET MVC Framework, but haven't had any success. Also, I've ran across a few similiar questions online, but haven't had any success there either. Seems like I'm missing something rather fundamental. Currently, I'm trying to use the action method parameters approach. Can someone point out where I'm going wrong or provide a simple example? Thanks in advance! Using Visual Studio 2008, ASP.NET MVC2 and C#: What I would like to do is take the data entered in the "Investigator" textbox and use it to filter investigators in the controller. I plan on doing this in the List method (which is already functional), however, I'm using the SearchResults method for debugging. Here's the textbox code from my view, SearchDetails: <h2>Search Details</h2> <% using (Html.BeginForm()) { %> <fieldset> <%= Html.ValidationSummary() %> <h4>Investigator</h4> <p> <%=Html.TextBox("Investigator")%> <%= Html.ActionLink("Search", "SearchResults")%> </p> </fieldset> <% } %> Here is the code from my controller, InvestigatorsController: private IInvestigatorsRepository investigatorsRepository; public InvestigatorsController(IInvestigatorsRepository investigatorsRepository) { //IoC: this.investigatorsRepository = investigatorsRepository; } public ActionResult List() { return View(investigatorsRepository.Investigators.ToList()); } public ActionResult SearchDetails() { return View(); } public ActionResult SearchResults(SearchCriteria search) { string test = search.Investigator; return View(); } I have an Investigator class: [Table(Name = "INVESTIGATOR")] public class Investigator { [Column(IsPrimaryKey = true, IsDbGenerated = false, AutoSync=AutoSync.OnInsert)] public string INVESTID { get; set; } [Column] public string INVEST_FNAME { get; set; } [Column] public string INVEST_MNAME { get; set; } [Column] public string INVEST_LNAME { get; set; } } and created a SearchCriteria class to see if I could get MVC to push the search criteria data to it and grab it in the controller: public class SearchCriteria { public string Investigator { get; set; } } } I'm not sure if project layout has anything to do with this either, but I'm using the 3 project approach suggested by Sanderson: DomainModel, Tests, and WebUI. The Investigator and SearcCriteria classes are in the DomainModel project and the other items mentioned here are in the WebUI project. Thanks again for any hints, tips, or simple examples! Mike

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  • Right-click context menu for Java JTree?

    - by arcanex
    I'm trying to implement pop-up menus in Java JTree. I've sub-classed DefaultTreeCellRenderer (to change node appearance) and DefaultTreeCellEditor (to create Components to attach event listeners to, since apparently the Components that DefaultTreeCellRenderer.getTreeCellRendererComponent() returns can't do it?). I don't really want to "edit" the nodes, just be able to pop-up a menu when a node gets right-clicked, but this is the only way I can think of doing it right now... Below is the code that I have so far-- I'm just trying to figure out how to capture MouseEvents. It sort of works, but badly. What's a better way to accomplish what I'm trying to do here? private class My_TreeCellRenderer extends DefaultTreeCellRenderer { My_TreeCellRenderer() { super (); } public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) { super.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, hasFocus); // set label text and tool tips setText(((My_Object)value).getTreeLabel()); setToolTipText(((My_Object)value).getTreeToolTip()); return this; } } private class My_TreeCellEditor extends DefaultTreeCellEditor { private MouseAdapter ma; My_TreeCellEditor(JTree tree, DefaultTreeCellRenderer renderer) { super (tree, renderer); ma = new MouseAdapter() { public void mousePressed(MouseEvent e) { if (e.isPopupTrigger()) { System.out.println("My Popup"); } } public void mouseReleased(MouseEvent e) { if (e.isPopupTrigger()) { System.out.println("My Popup"); } } }; } public Component getTreeCellEditorComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row) { String src_filename = null; // return non-editing component Component c = renderer.getTreeCellRendererComponent(tree, value, selected, expanded, leaf, row, true); // add mouse listener if it's not listening already MouseListener mouseListeners[] = c.getMouseListeners(); int i; for (i=0; i < mouseListeners.length && mouseListeners[i] != ma; i++); if (i >= mouseListeners.length) c.addMouseListener(ma); return c; } protected boolean canEditImmediately(EventObject event) { if (event instanceof MouseEvent && ((MouseEvent)event).getClickCount() == 1) return true; else return false; } }

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  • Using Xlib via JNA to move a window

    - by rob
    I'm using JNA to manipulate application windows on Linux by sending Xlib messages but can't seem to move a window. My original implementation executed wmctrl on the shell to move the windows and that successfully moved the windows. Unfortunately, there's a noticeable amount of overhead associated with calling shell programs from Java, so now I'm trying to make direct API calls using JNA. I'm using the X11 example available from the JNA website and can successfully do a few tricks, such as enumerating the window IDs and reading window properties, so I know JNA+Xlib is at least partially working. First I tried moving the windows directly using XMoveWindow() but the window manager was apparently blocking those calls. I ran across a thread that suggested I needed to send a client message using XSendMessage(), so I've done that below, but apparently XSendMessage() is failing because the window doesn't move and I get a return value of 0. I'm guessing I omitted something obvious, but can't quite figure it out. Any suggestions? Note that, for the purposes of this example, the main method has a window ID hard-coded. This is the window ID of the window I'm trying to move (obtained using wmctrl -l on the console). import com.sun.jna.NativeLong; import com.sun.jna.Pointer; import com.sun.jna.examples.unix.X11; import com.sun.jna.examples.unix.X11.Atom; import com.sun.jna.examples.unix.X11.AtomByReference; import com.sun.jna.examples.unix.X11.Display; import com.sun.jna.examples.unix.X11.Window; import com.sun.jna.examples.unix.X11.WindowByReference; import com.sun.jna.examples.unix.X11.XEvent; import com.sun.jna.examples.unix.X11.XTextProperty; import com.sun.jna.examples.unix.X11.XWindowAttributes; import com.sun.jna.ptr.IntByReference; import com.sun.jna.ptr.NativeLongByReference; import com.sun.jna.ptr.PointerByReference; private static final int FALSE = 0; /** C-style boolean "false" */ private static final int TRUE = 1; /** C-style boolean "true" */ public static void main(String[] args) { setWindowPos(new Window(0x01300007), 100, 100, 600, 400); // update the Window constructor with the appropriate ID given by wmctrl -l } public static boolean setWindowPos(Window window, int x, int y, int w, int h) { final X11 x11 = X11.INSTANCE; Display display = x11.XOpenDisplay(null); NativeLong mask = new NativeLong(X11.SubstructureRedirectMask | X11.SubstructureNotifyMask | X11.ResizeRedirectMask); XEvent event = new XEvent(); String msg = "_NET_MOVERESIZE_WINDOW"; //$NON-NLS-1$ long grflags = 0l; // use the default gravity of the window if (x != -1) grflags |= (1 << 8); if (y != -1) grflags |= (1 << 9); if (w != -1) grflags |= (1 << 10); if (h != -1) grflags |= (1 << 11); event.xclient.type = X11.ClientMessage; event.xclient.serial = new NativeLong(0l); event.xclient.send_event = TRUE; event.xclient.message_type = x11.XInternAtom(display, msg, false); event.xclient.window = window; event.xclient.format = 32; event.xclient.data.l[0] = new NativeLong(grflags); // gravity flags event.xclient.data.l[1] = new NativeLong(x); event.xclient.data.l[2] = new NativeLong(y); event.xclient.data.l[3] = new NativeLong(w); event.xclient.data.l[4] = new NativeLong(h); int status = x11.XSendEvent(display, x11.XDefaultRootWindow(display), FALSE, mask, event); x11.XFlush(display); // need to XFlush if we're not reading X events if (status == 0) { // 0 indicates XSendEvent failed logger.error("setWindowPos: XSendEvent failed (" + msg + ")"); //$NON-NLS-1$ return false; } return true; }

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  • Jquery hiding all descendents of a ul tag...showing child elements as tree menu...

    - by Ronedog
    I want to hide all the descendents of the "ul" for my tree menu when the page loads up, then as each "main" "li" link is clicked display the direct child, and if the direct child has children (grandchild), when the the "Child" is clicked I want it to show the "grandchild" elements. should be simple, but some how I screwed things up and when i click on the main "li" (Heading 1) it displays all of the descendents (Including the "Sub page A - 1"), instead of just the direct children ("Sub Page A"). Which I think means the children, grandchildren, etc. were never hidden to begin with with the .hide(). What I really want to happen is to hide all the descendents (except the main top-level headings) and as I walk down the tree display the children as needed. Any tips on how to make this work? Here's the HTML: <ul id="nav"> <li>Heading 1 <ul> <li>Sub page A <ul> <li>Sub page A - 1</li> <li>Sub page A - 3</li> <li>Sub page A - 2</li> </ul> </li> <li>Sub page B</li> <li>Sub page C</li> </ul> </li> <li>Heading 2 <ul> <li>Sub page D</li> <li>Sub page E</li> <li>Sub page F</li> </ul> </li> <li>Heading 3 <ul> <li>Sub page G</li> <li>Sub page H</li> <li>Sub page I</li> </ul> </li> Here's my Jquery: $(function(){ $('#nav ul').hide(); //Supposed to Hide all <ul> tags for all descendents, but doesn't work $('#nav>li').mouseover(function(){ $(this).addClass("a_hand") }); //Add the class that displays the hand $('#nav>li').toggle(function() { $(this).find('ul').slideDown(200); }, function() { $(this).find('ul').slideUp(200); });//END TOGGLE });//END MAIN FUNCTION thanks.

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  • Dojo JsonRest store and dijit.Tree

    - by user1427712
    I'm having a some problem making JSonRest store and dijit.Tree with ForestModel. I've tried some combination of JsonRestStore and json data format following many tips on the web, with no success. At the end, taking example form here http://blog.respondify.se/2011/09/using-dijit-tree-with-the-new-dojo-object-store/ I've made up this simple page (I'm using dojotolkit 1.7.2) <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Tree Model Explorer</title> <script type="text/javascript"> djConfig = { parseOnLoad : true, isDebug : true, } </script> <script type="text/javascript" djConfig="parseOnLoad: true" src="lib/dojo/dojo.js"></script> <script type="text/javascript"> dojo.require("dojo.parser"); dojo.require("dijit.Tree"); dojo.require("dojo.store.JsonRest"); dojo.require("dojo.data.ObjectStore"); dojo.require("dijit.tree.ForestStoreModel"); dojo.addOnLoad(function() { var objectStore = new dojo.store.JsonRest({ target : "test.json", labelAttribute : "name", idAttribute: "id" }); var dataStore = new dojo.data.ObjectStore({ objectStore : objectStore }); var treeModel = new dijit.tree.ForestStoreModel({ store : dataStore, deferItemLoadingUntilExpand : true, rootLabel : "Subjects", query : { "id" : "*" }, childrenAttrs : [ "children" ] }); var tree = new dijit.Tree({ model : treeModel }, 'treeNode'); tree.startup(); }); </script> </head> <body> <div id="treeNode"></div> </body> </html> My rest service responds the following json { data: [ { "id": "PippoId", "name": "Pippo", "children": [] }, { "id": "PlutoId", "name": "Pluto", "children": [] }, { "id": "PaperinoId", "name": "Paperino", "children": [] } ]} I've tried also with the following response (actually my final intention n is to use lazy loading for the tree) { data: [ { "id": "PippoId", "name": "Pippo", "$ref": "author0", "children": true }, { "id": "PlutoId", "name": "Pluto", "$ref": "author1", "children": true }, { "id": "PaperinoId", "name": "Paperino", "$ref": "author2", "children": true } ]} Neither of the two works. I see no error message in firebug. I simply see the root "Subject" on the page. Thanks to anybody could help in some way.

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  • WCF help, how can I expose a service over http, that calls another service over net.tcp?

    - by Hcabnettek
    Hi All, I have a WCF .svc file hosted in IIS. I want to use basicHTTP binding. This services job is to actually call another service over net.tcp. Everything works fine locally, but when I deployed, I'm getting this error. The provided URI scheme 'http' is invalid; expected 'net.tcp'. Parameter name: via Here is the server config <client> <endpoint address="net.tcp://localhost:9300/InternalInterfaceService" binding="netTcpBinding" bindingConfiguration="NetTcpBinding_IInternalInterfaceService" contract="IInternalInterfaceService" name="NetTcpBinding_IInternalInterfaceService"> <identity> <servicePrincipalName value="localhost" /> </identity> </endpoint> </client> <services> <service name="MyExternalService"> <endpoint address="" binding="basicHttpBinding" contract="IMyExternalService" /> </service> </services> And here is the config that svcutil generates <system.serviceModel> <bindings> <basicHttpBinding> <binding name="BasicHttpBinding_IMyExternalService" closeTimeout="00:01:00" openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00" allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard" maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered" useDefaultWebProxy="true"> <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384" maxBytesPerRead="4096" maxNameTableCharCount="16384" /> <security mode="None"> <transport clientCredentialType="None" proxyCredentialType="None" realm="" /> <message clientCredentialType="UserName" algorithmSuite="Default" /> </security> </binding> </basicHttpBinding> </bindings> <client> <endpoint address="http://myserver.somesdomain.com/Services/MyExternalService.svc" binding="basicHttpBinding" bindingConfiguration="BasicHttpBinding_IMyExternalService" contract="IMyInternalService" name="BasicHttpBinding_IMyExternalService" /> </client> </system.serviceModel> What do I need to do to wire this up correctly. I do not want to expose InternalInterfaceService over http. What am I doing incorrectly here? Any tips or suggestions are certainly appreciated. Thanks, ~ck

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  • Injecting generics with Guice

    - by paradigmatic
    I am trying to migrate a small project, replacing some factories with Guice (it is my first Guice trial). However, I am stuck when trying to inject generics. I managed to extract a small toy example with two classes and a module: import com.google.inject.Inject; public class Console<T> { private final StringOutput<T> out; @Inject public Console(StringOutput<T> out) { this.out = out; } public void print(T t) { System.out.println(out.converter(t)); } } public class StringOutput<T> { public String converter(T t) { return t.toString(); } } import com.google.inject.AbstractModule; import com.google.inject.Guice; import com.google.inject.Injector; import com.google.inject.TypeLiteral; public class MyModule extends AbstractModule { @Override protected void configure() { bind(StringOutput.class); bind(Console.class); } public static void main(String[] args) { Injector injector = Guice.createInjector( new MyModule() ); StringOutput<Integer> out = injector.getInstance(StringOutput.class); System.out.println( out.converter(12) ); Console<Double> cons = injector.getInstance(Console.class); cons.print(123.0); } } When I run this example, all I got is: Exception in thread "main" com.google.inject.CreationException: Guice creation errors: 1) playground.StringOutput<T> cannot be used as a key; It is not fully specified. at playground.MyModule.configure(MyModule.java:15) 1 error at com.google.inject.internal.Errors.throwCreationExceptionIfErrorsExist(Errors.java:354) at com.google.inject.InjectorBuilder.initializeStatically(InjectorBuilder.java:152) at com.google.inject.InjectorBuilder.build(InjectorBuilder.java:105) at com.google.inject.Guice.createInjector(Guice.java:92) I tried looking for the error message, but without finding any useful hints. Further on the Guice FAQ I stumble upon a question about how to inject generics. I tried to add the following binding in the configure method: bind(new TypeLiteral<StringOutput<Double>>() {}).toInstance(new StringOutput<Double>()); But without success (same error message). Can someone explain me the error message and provide me some tips ? Thanks.

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  • Tactics for using PHP in a high-load site

    - by Ross
    Before you answer this I have never developed anything popular enough to attain high server loads. Treat me as (sigh) an alien that has just landed on the planet, albeit one that knows PHP and a few optimisation techniques. I'm developing a tool in PHP that could attain quite a lot of users, if it works out right. However while I'm fully capable of developing the program I'm pretty much clueless when it comes to making something that can deal with huge traffic. So here's a few questions on it (feel free to turn this question into a resource thread as well). Databases At the moment I plan to use the MySQLi features in PHP5. However how should I setup the databases in relation to users and content? Do I actually need multiple databases? At the moment everything's jumbled into one database - although I've been considering spreading user data to one, actual content to another and finally core site content (template masters etc.) to another. My reasoning behind this is that sending queries to different databases will ease up the load on them as one database = 3 load sources. Also would this still be effective if they were all on the same server? Caching I have a template system that is used to build the pages and swap out variables. Master templates are stored in the database and each time a template is called it's cached copy (a html document) is called. At the moment I have two types of variable in these templates - a static var and a dynamic var. Static vars are usually things like page names, the name of the site - things that don't change often; dynamic vars are things that change on each page load. My question on this: Say I have comments on different articles. Which is a better solution: store the simple comment template and render comments (from a DB call) each time the page is loaded or store a cached copy of the comments page as a html page - each time a comment is added/edited/deleted the page is recached. Finally Does anyone have any tips/pointers for running a high load site on PHP. I'm pretty sure it's a workable language to use - Facebook and Yahoo! give it great precedence - but are there any experiences I should watch out for? Thanks, Ross

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  • How optimize code with introspection + heavy alloc on iPhone

    - by mamcx
    I have a problem. I try to display a UITable that could have 2000-20000 records (typicall numbers.) I have a SQLite database similar to the Apple contacts application. I do all the tricks I know to get a smoth scroll, but I have a problem. I load the data in 50 recods blocks. Then, when the user scroll, request next 50 until finish the list. However, load that 50 records cause a notable "pause" in loading and scrolling. Everything else works fine. I cache the data, have opaque cells, draw it by code, etc... I swap the code loading the same data in dicts and have a performance boost but wonder if I could keep my object oriented aproach and improve the actual code. This is the code I think have the performance problem: -(NSArray *) loadAndFill: (NSString *)sql theClass: (Class)cls { [self openDb]; NSMutableArray *list = [NSMutableArray array]; NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init]; DbObject *ds; Class myClass = NSClassFromString([DbObject getTableName:cls]); FMResultSet *rs = [self load:sql]; while ([rs next]) { ds = [[myClass alloc] init]; NSDictionary *props = [ds properties]; NSString *fieldType = nil; id fieldValue; for (NSString *fieldName in [props allKeys]) { fieldType = [props objectForKey: fieldName]; fieldValue = [self ValueForField:rs Name:fieldName Type:fieldType]; [ds setValue:fieldValue forKey:fieldName]; } [list addObject :ds]; [ds release]; } [rs close]; [pool drain]; return list; } And I think the main culprit is: -(id) ValueForField: (FMResultSet *)rs Name:(NSString *)fieldName Type:(NSString *)fieldType { id fieldValue = nil; if ([fieldType isEqualToString:@"i"] || // int [fieldType isEqualToString:@"I"] || // unsigned int [fieldType isEqualToString:@"s"] || // short [fieldType isEqualToString:@"S"] || // unsigned short [fieldType isEqualToString:@"f"] || // float [fieldType isEqualToString:@"d"] ) // double { fieldValue = [NSNumber numberWithInt: [rs longForColumn:fieldName]]; } else if ([fieldType isEqualToString:@"B"]) // bool or _Bool { fieldValue = [NSNumber numberWithBool: [rs boolForColumn:fieldName]]; } else if ([fieldType isEqualToString:@"l"] || // long [fieldType isEqualToString:@"L"] || // usigned long [fieldType isEqualToString:@"q"] || // long long [fieldType isEqualToString:@"Q"] ) // unsigned long long { fieldValue = [NSNumber numberWithLong: [rs longForColumn:fieldName]]; } else if ([fieldType isEqualToString:@"c"] || // char [fieldType isEqualToString:@"C"] ) // unsigned char { fieldValue = [rs stringForColumn:fieldName]; //Is really a boolean? if ([fieldValue isEqualToString:@"0"] || [fieldValue isEqualToString:@"1"]) { fieldValue = [NSNumber numberWithInt: [fieldValue intValue]]; } } else if ([fieldType hasPrefix:@"@"] ) // Object { NSString *className = [fieldType substringWithRange:NSMakeRange(2, [fieldType length]-3)]; if ([className isEqualToString:@"NSString"]) { fieldValue = [rs stringForColumn:fieldName]; } else if ([className isEqualToString:@"NSDate"]) { NSDateFormatter* dateFormatter = [[NSDateFormatter alloc] init]; [dateFormatter setDateFormat:@"yyyy-MM-dd'T'HH:mm:ss"]; NSString *theDate = [rs stringForColumn:fieldName]; if (theDate) { fieldValue = [dateFormatter dateFromString: theDate]; } else { fieldValue = nil; } [dateFormatter release]; } else if ([className isEqualToString:@"NSInteger"]) { fieldValue = [NSNumber numberWithInt: [rs intForColumn :fieldName]]; } else if ([className isEqualToString:@"NSDecimalNumber"]) { fieldValue = [rs stringForColumn :fieldName]; if (fieldValue) { fieldValue = [NSDecimalNumber decimalNumberWithString:[rs stringForColumn :fieldName]]; } } else if ([className isEqualToString:@"NSNumber"]) { fieldValue = [NSNumber numberWithDouble: [rs doubleForColumn:fieldName]]; } else { //Is a relationship one-to-one? if (![fieldType hasPrefix:@"NS"]) { id rel = class_createInstance(NSClassFromString(className), sizeof(unsigned)); Class theClass = [rel class]; if ([rel isKindOfClass:[DbObject class]]) { fieldValue = [rel init]; //Load the record... NSInteger Id = [rs intForColumn:[theClass relationName]]; if (Id>0) { [fieldValue release]; Db *db = [Db currentDb]; fieldValue = [db loadById: theClass theId:Id]; } } } else { NSString *error = [NSString stringWithFormat:@"Err Can't get value for field %@ of type %@", fieldName, fieldType]; NSLog(error); NSException *e = [NSException exceptionWithName:@"DBError" reason:error userInfo:nil]; @throw e; } } } return fieldValue; }

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  • Visual Web Developer 2008 Express and XHTML 1.1 (not applying)

    - by Mike Valeriano
    Hello. I may be missing something since I'm not used to work with IDEs for web development, so please understand if I'm doing something stupid. I've picked a copy of Beginning ASP.NET 3.5 in C# and VB to try and learn this thing quickly. I'm no HTML guru, but I know something about the DTDs and I want to either use XHTML 1.0 Strict or XHTML 1.1 while learning the ins and outs of ASP.NET. Following the book (just started actually), I'm not having any trouble understanding the concepts, since I have a C# background, but what I don't understand is how VWD goes about applying the schema you select for validation. The book explains that the drop-down list on the toolbar is enough to set this, so that's what I did: I've selected XHTML 1.1 (since there is no 1.0 strict option, what I find really odd) and then started the project. The thing is that the code generated automatically for the Default page had the XHTML 1.0 transitional DTD. Every other page added had the same DTD, even though XHTML 1.1 is still the selected schema in the drop-down list. I decided to test it out and there it was: inserting some text in the design view and then applying a bold formatting just inserted < b tags on the code. Changing color does add a span tag with added CSS though. What I want to know is: if I want strict XHTML (or 1.1) should I just code it manually? Or is there a "fix" for this problem (having a schema selected but not applied by the IDE)? Am I missing something really easy and dumb? I have no problem with coding it manually - I actually prefer doing that. The thing is that I really wanna try this WYSIWYG approach for once, since some developers swear by it. Plus I don't know yet if I'll need special tags for ASP.NET, so I think having them inserted automatically should be the best practice. I couldn't find any similar problems around (MSDN, Google, here), and as far as the book goes (up to the point I've read), this is the expected VWD behavior, which I find suspect at least. Sorry for the long text (and poor English - not my primary language). Thanks in advance for any help/tips.

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  • Does my fat-client application belong in the MVC pattern?

    - by boatingcow
    The web-based application I’m currently working on is growing arms and legs! It’s basically an administration system which helps users to keep track of bookings, user accounts, invoicing etc. It can also be accessed via a couple of different websites using a fairly crude API. The fat-client design loosely follows the MVC pattern (or perhaps MVP) with a php/MySQL backend, Front Controller, several dissimilar Page Controllers, a liberal smattering of object-oriented and procedural Models, a confusing bunch of Views and templates, some JavaScripts, CSS files and Flash objects. The programmer in me is a big fan of the principle of “Separation of Concerns” and on that note, I’m currently trying to figure out the best way to separate and combine the various concerns as the project grows and more people contribute to it. The problem we’re facing is that although JavaScript (or Flash with ActionScript) is normally written with the template, hence part of the View and decoupled from the Controller and Model, we find that it actually encompasses the entire MVC pattern... Swap an image with an onmouseover event - that’s Behaviour. Render a datagrid - we’re manipulating the View. Send the result of reordering a list via AJAX - now we’re in Control. Check a form field to see if an email address is in a valid format - we’re consulting the Model. Is it wise to let the database people write up the validation Model with jQuery? Can the php programmers write the necessary Control structures in JavaScript? Can the web designers really write a functional AJAX form for their View? Should there be a JavaScript overlord for every project? If the MVC pattern could be applied to the people instead of the code, we would end up with this: Model - the database boffins - “SELECT * FROM mind WHERE interested IS NULL” Control - pesky programmers - “class Something extends NothingAbstractClass{…}” View - traditionally the domain of the graphic/web designer - “” …and a new layer: Behaviour - interaction and feedback designer - “CSS3 is the new black…” So, we’re refactoring and I’d like to stick to best practice design, but I’m not sure how to proceed. I don’t want to reinvent the wheel, so would anyone have any hints or tips as to what pattern I should be looking at or any code samples from someone who’s already done the dirty work? As the programmer guy, how can I rewrite the app for backend and front end whilst keeping the two separate? And before you ask, yes I’ve looked at Zend, CodeIgnitor, Symfony, etc., and no, they don’t seem to cross the boundary between server logic and client logic!

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  • Freezes (not crashes) with GCD, blocks and Core Data

    - by Lukasz
    I have recently rewritten my Core Data driven database controller to use Grand Central Dispatch to manage fetching and importing in the background. Controller can operate on 2 NSManagedContext's: NSManagedObjectContext *mainMoc instance variable for main thread. this contexts is used only by quick access for UI by main thread or by dipatch_get_main_queue() global queue. NSManagedObjectContext *bgMoc for background tasks (importing and fetching data for NSFetchedresultsController for tables). This background tasks are fired ONLY by user defined queue: dispatch_queue_t bgQueue (instance variable in database controller object). Fetching data for tables is done in background to not block user UI when bigger or more complicated predicates are performed. Example fetching code for NSFetchedResultsController in my table view controllers: -(void)fetchData{ dispatch_async([CDdb db].bgQueue, ^{ NSError *error = nil; [[self.fetchedResultsController fetchRequest] setPredicate:self.predicate]; if (self.fetchedResultsController && ![self.fetchedResultsController performFetch:&error]) { NSSLog(@"Unresolved error in fetchData %@", error); } if (!initial_fetch_attampted)initial_fetch_attampted = YES; fetching = NO; dispatch_async(dispatch_get_main_queue(), ^{ [self.table reloadData]; [self.table scrollRectToVisible:CGRectMake(0, 0, 100, 20) animated:YES]; }); }); } // end of fetchData function bgMoc merges with mainMoc on save using NSManagedObjectContextDidSaveNotification: - (void)bgMocDidSave:(NSNotification *)saveNotification { // CDdb - bgMoc didsave - merging changes with main mainMoc dispatch_async(dispatch_get_main_queue(), ^{ [self.mainMoc mergeChangesFromContextDidSaveNotification:saveNotification]; // Extra notification for some other, potentially interested clients [[NSNotificationCenter defaultCenter] postNotificationName:DATABASE_SAVED_WITH_CHANGES object:saveNotification]; }); } - (void)mainMocDidSave:(NSNotification *)saveNotification { // CDdb - main mainMoc didSave - merging changes with bgMoc dispatch_async(self.bgQueue, ^{ [self.bgMoc mergeChangesFromContextDidSaveNotification:saveNotification]; }); } NSfetchedResultsController delegate has only one method implemented (for simplicity): - (void)controllerDidChangeContent:(NSFetchedResultsController *)controller { dispatch_async(dispatch_get_main_queue(), ^{ [self fetchData]; }); } This way I am trying to follow Apple recommendation for Core Data: 1 NSManagedObjectContext per thread. I know this pattern is not completely clean for at last 2 reasons: bgQueue not necessarily fires the same thread after suspension but since it is serial, it should not matter much (there is never 2 threads trying access bgMoc NSManagedObjectContext dedicated to it). Sometimes table view data source methods will ask NSFetchedResultsController for info from bgMoc (since fetch is done on bgQueue) like sections count, fetched objects in section count, etc.... Event with this flaws this approach works pretty well of the 95% of application running time until ... AND HERE GOES MY QUESTION: Sometimes, very randomly application freezes but not crashes. It does not response on any touch and the only way to get it back to live is to restart it completely (switching back to and from background does not help). No exception is thrown and nothing is printed to the console (I have Breakpoints set for all exception in Xcode). I have tried to debug it using Instruments (time profiles especially) to see if there is something hard going on on main thread but nothing is showing up. I am aware that GCD and Core Data are the main suspects here, but I have no idea how to track / debug this. Let me point out, that this also happens when I dispatch all the tasks to the queues asynchronously only (using dispatch_async everywhere). This makes me think it is not just standard deadlock. Is there any possibility or hints of how could I get more info what is going on? Some extra debug flags, Instruments magical tricks or build setting etc... Any suggestions on what could be the cause are very much appreciated as well as (or) pointers to how to implement background fetching for NSFetchedResultsController and background importing in better way.

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  • EXT-GWT Portal: How to get all Portlets?

    - by Lars
    Hi all this is my first Question here! Im just making my first steps with (Ext-) GWT. I´m testing the Ext-GWT libraries and really: These are absolute great! Now my question: Is it possible to make a kind of "clear-Portal" or "hide all portles" for a defined Portal? Or have i always manually clear the portal like in my example code above? My sample code looks like this: //define the Portal, 2 columns, each 50% auf width, with borders and Backgroundcolor portal = new Portal(2); portal.setBorders(true); portal.setStyleAttribute("backgroundColor", "white"); portal.setColumnWidth(0, .50); portal.setColumnWidth(1, .50); //define a Portlet for showing all Users portletUser = new Portlet(); portletUser.setHeading("Benutzer"); configPanel(portletUser); portletUser.setLayout(new FitLayout()); CompUserList compUserList = new CompUserList(); portletUser.add(compUserList); portletUser.setHeight(250); //define a Portlet for showing all Vehicles portletVehicles = new Portlet(); portletVehicles.setHeading("Fahrzeuge"); configPanel(portletVehicles); portletVehicles.setLayout(new FitLayout()); CompVehicleList compVehicleList = new CompVehicleList(); portletVehicles.add(compVehicleList); portletVehicles.setHeight(250); //define a portlet for showing all countries portletCountries = new Portlet(); portletCountries.setHeading("Länder"); configPanel(portletCountries); portletCountries.setLayout(new FitLayout()); CompCountryList compCountryList = new CompCountryList(); portletCountries.add(compCountryList); portletCountries.setHeight(250); //add both Portlets to Portal portal.add(portletUser, 0); portal.add(portletVehicles, 1); So first of all this works fine and looks great :-) Now i have a a button in a accordeon menu. The Listener on this button should hide all portlets in the portal (at this time its the portletUser and portletVehicles) and then add another portlet (for example the portletCountries): portletUser.hide(); portletVehicles.hide(); portal.add(portletCountries, 0) Question from above again ;-) Is it possible to make a kind of "clear-Portal" or "hide all portles" for a defined Portal? Or have i always manually clear the portal like in my example code above? What is the best practice for this functionallity? Thanks all for your tips! Lars.

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  • Looking for efficient scaling patterns for Silverlight application with distributed text-file data s

    - by Edward Tanguay
    I'm designing a Silverlight software solution for students and teachers to record flashcards, e.g. words and phrases that students find while reading and errors that teachers notice while teaching. Requirements are: each person publishes his own flashcards in a file on a web server, e.g. http://:www.mywebserver.com/flashcards.txt other people subscribe to that person's flashcards by using a Silverlight flashcard reader that I have developed and entering the URLs of flashcard files they want to subscribe to, URLs and imported flashcards being saved in IsolatedStorage the flashcards.txt file has the following simple format: title, then blocks of question/answers: Jim Smith's flashcards from English class 53-222, winter semester 2009 ==fla Das kann nicht sein. That can't be. ==fla Es sei denn, er kommt nicht. Unless he doesn't come. The user then makes public the URL to his flashcard file and other readers begin reading in his flashcards. In order to lower the bar for non-technical users to contribute, it will even be possible for them to save this text in a Google Document, which they publish and distribute the URL. The flashcard readers will then recognize it is a google document and perform the necessary screen scraping to get at the raw text. I have two technical questions about this approach: What is a best way to plan now for scalability issues: e.g. if your reader is subscribed to 10 flashcard files that are each 200K, it will have to download 2MB of text just to find out if any new flashcards are available. Or can I somehow accurately and consistently get at the last update date/time of text files on servers and published google docs? Each reader will have the ability to allow the person to test himself on imported flashcards and add meta information to them, e.g. categorize them, edit them, etc. This information will be stored in IsolatedStorage along with the important flashcards themselves. What is a good pattern to allow these readers to share and synchronize this meta data, e.g. so when you are looking at a flashcard you can see that 5 other people have made corrections to it. The best solution I can think of now is that the Silverlight readers will have to republish their data to a central database, but then there is the problem of uniquely identifying each flashcard, the best approach seems to be URL + position-in-file, or even better URL + original text of both question and answer fields, but both of these have their obvious drawbacks. The main requirement is that the bar for participation is kept as low as possible, i.e. type text in a google document, publish it, distribute the URL, and you're publishing within the flashcard community. So I want to come up with the most efficient technical solutions in order to compensate for the lack of database, lack of unique ids, etc. For those who have designed or developed similar non-traditional, distributed database projects like this, what advice, experience or best-practice tips you can share on the above two points?

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  • foreach loop corrupting my array?

    - by WmasterJ
    Explanation I have a multidimensional array that is iterated over to created a categorized view of people with different research interests. The main array look something like this: Array ( ... ['Cell Biology'] => Array(4 elements) ['Molecular'] => Array(6 elements) ['Biology Education'] => Array(14 elements) ['Plant Biology'] => Array(19 elements) <--- Last element in array ) I know that the entire array is intact and correctly structured. The only information that is inside these array is an user id, like so: Array ('Plant Biology') 19 elements ( [0] => 737 [1] => 742 [2] => 748 ... ) My problem is that after i run the main array through a foreach loop the last 'sub-array' gets messed up. By messed up I mean that what you see about instead look like: String (13 characters) 'Plant Biology' This is without doing at all anything inside the loop with to the array that gets corrupted. Any tips to what it might be? PHP Code // ---> Array is OK here echo "<h2>Research divided</h2>"; // Loop areas and list them in 2 columns foreach($research['areas'] as $area => $areaArray) { // ---> Here it is already corrupted $count = count($areaArray); if($count > 0) { echo "<h3>$area</h3><hr/>"; echo "<table class='area_list'><tr>"; // Loop users within areas, divided up in 2 columns for($i=0 ; $i<$count ; $i++) { $uid = $areaArray[$i]; echo "<li>$uid</li>"; } echo "</tr></table>"; } }

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  • Convert a PDF to a Transparent PNG with GhostScript

    - by Jonathon Wolfe
    Hi all. I am attempting, unsuccessfully, to use Ghostscript to rasterize PDF files with a transparent background to PNG files with a transparent background. I've searched high and low for questions from others attempting the same thing and none of the posted solutions, which as far as I can tell come down to specifying -sDEVICE=pngalpha, have worked with my test files. At this point I would really appreciate any advice or tips a more experienced hand could provide. My test PDF is located here: http://www.kolossus.com/files/test.pdf It could be that the issue is with this file, but I doubt it. As far as I can tell, it has no specified background, and when I open the file with a transparency-aware app like Photoshop or Illustrator, sure enough it displays with a transparent background. However, when opened with an application like Adobe Reader the file is rendered with a white background. I believe that this has more to do with the application rendering the PDF than with the PDF itself -- apps like Adobe Reader assume you want to see what a printed document will look like and therefore always show a white canvas behind the artwork -- but I can't be sure. The gs command I'm using is: gs -dNOPAUSE -dBATCH -sDEVICE=pngalpha -r72 -sOutputFile=test.png test.pdf This produces a PNG that has transparent pixels outside of the bounding box of the artwork in the file, but all pixels that are inside the artwork's bounding box are rasterized against a white background. This is a problem for me, as my artwork has drop shadows and antialiased edges that need to be preserved in the final output, and can't just be postprocessed out with ImageMagick. A sample of my PNG output is at the same location as the pdf above, with .png at the end (stackoverflow won't let me include more than one url in my post). Interestingly, I see no effects from using the -dBackgroundColor flag, even if I set it to something non-white like -dBackgroundColor=16#ff0000. Perhaps my understanding of the syntax of this flag is wrong. Also interestingly, I see no effects from using the -dTextAlphaBits=4 -dGraphicsAlphaBits=4 flags to try to enable subpixel antialiasing. I would also appreciate any advice on how to enable subpixel antialiasing, especially on text. Finally, I'm using GPL Ghostscript 8.64 on Mac OS 10.5.7, and the rendering workflow I'm trying to get set up is to generate transparent PNG images from PDFs output by PrinceXML. I'm calling Ghostscript directly for the rasterization instead of using ImageMagick because ImageMagick delegates to Ghostscript for PDF rasterization and I should be able to control the rasterization better by calling GS directly. Thanks for your help. -Jon Wolfe

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