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Articles indexed in November 2011

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• C# Function Inheritance--Use Child Class Vars with Base Class Function

  - by Sean O'Connor

  Good day, I have a fairly simple question to experienced C# programmers. Basically, I would like to have an abstract base class that contains a function that relies on the values of child classes. I have tried code similar to the following, but the compiler complains that SomeVariable is null when SomeFunction() attempts to use it. Base class: public abstract class BaseClass { protected virtual SomeType SomeVariable; public BaseClass() { this.SomeFunction(); } protected void SomeFunction() { //DO SOMETHING WITH SomeVariable } } A child class: public class ChildClass:BaseClass { protected override SomeType SomeVariable=SomeValue; } Now I would expect that when I do: ChildClass CC=new ChildClass(); A new instance of ChildClass should be made and CC would run its inherited SomeFunction using SomeValue. However, this is not what happens. The compiler complains that SomeVariable is null in BaseClass. Is what I want to do even possible in C#? I have used other managed languages that allow me to do such things, so I certain I am just making a simple mistake here. Any help is greatly appreciated, thank you.

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• PHP database selection issue

  - by Citroenfris

  I'm in a bit of a pickle with freshening up my PHP a bit, it's been about 3 years since I last coded in PHP. Any insights are welcomed! I'll give you as much information as I possibly can to resolve this error so here goes! Files config.php database.php news.php BLnews.php index.php Includes config.php - news.php database.php - news.php news.php - BLnews.php BLnews.php - index.php Now the problem with my current code is that the database connection is being made but my database refuses to be selected. The query I have should work but due to my database not getting selected it's kind of annoying to get any data exchange going! database.php <?php class Database { //------------------------------------------- // Connects to the database //------------------------------------------- function connect() { if (isset($dbhost) && isset($dbuser) && isset($dbpass)) { $con = mysql_connect($dbhost, $dbuser, $dbpass) or die("Could not connect: " . mysql_error()); } }// end function connect function selectDB() { if (isset($dbname) && isset($con)) { $selected_db = mysql_select_db($dbname, $con) or die("Could not select test DB"); } } } // end class Database ?> News.php <?php // include the config file and database class include 'config.php'; include 'database.php'; ... ?> BLnews.php <?php // include the news class include 'news.php'; // create an instance of the Database class and call it $db $db = new Database; $db -> connect(); $db->selectDB(); class BLnews { function getNews() { $sql = "SELECT * FROM news"; if (isset($sql)) { $result = mysql_query($sql) or die("Could not execute query. Reason: " .mysql_error()); } return $result; } ?> index.php <?php ... include 'includes/BLnews.php'; $blNews = new BLnews(); $news = $blNews->getNews(); ?> ... <?php while($row = mysql_fetch_array($news)) { echo '<div class="post">'; echo '<h2><a href="#"> ' . $row["title"] .'</a></h2>'; echo '<p class="post-info">Posted by <a href="#"> </a> | <span class="date"> Posted on <a href="#">' . $row["date"] . '</a></span></p>'; echo $row["content"]; echo '</div>'; } ?> Well this is pretty much everything that should get the information going however due to the mysql_error in $result = mysql_query($sql) or die("Could not execute query. Reason: " .mysql_error()); I can see the error and it says: Could not execute query. Reason: No database selected I honestly have no idea why it would not work and I've been fiddling with it for quite some time now. Help is most welcomed and I thank you in advance! Greets Lemon

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• How to call function on parent page from iframe using jQuery?

  - by Michael

  I have an upload form that posts to a hidden iframe. I am attempting to call a function on the parent page from the iframe, but am getting the error "top.stopUpload is not a function". What is the correct way to do this? PARENT PAGE: $(document).ready(function() { $('#document_upload').submit( function() { $('#upload_progress').show(); }); function stopUpload(success){ if (success == 1){ $('#result', window.parent.document).html( '<span class="msg">The file was uploaded successfully!<\/span>'); } else { $('#result', window.parent.document).html( '<span class="emsg">There was an error during file upload!<\/span>'); } $('#upload_progress').hide(); return true; } }) IFRAME: $(document).ready(function() { top.stopUpload(<?php echo $result; ?>); }

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• JPA Bidirectional OneToMany and ManyToOne?

  - by PhoenixJon

  I'm using Oracle JDeveloper 11g Release 2. I created two tables A and B using SQL developer. Table A has a FK to table B. Using the Entities from Tables function, I created two JPA files from it. A has @ManyToOne annotation on FK. And also B has @OneToMany annotation to A. I don't want this. Can I remove this @OneToMany annotation automatically? public class A implements Serializable { ... @ManyToOne @JoinColumn(name = "FIELD_B") private B b; ... } public class B implements Serializable { ... @OneToMany(mappedBy = "B") private List<A> assetList; ... } I don't need @OneToMany mapping.

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• How does timezone really work in relation to PHP and MYSQL?

  - by Rick

  I am getting very strange results in terms of timezones. I am currently using Wordpress and everytime I register a new user, I see the wrong datetime in the database. Ok so I am suspecting it is picking up the server time. So then I then set in php.ini to have date.timezone = "America/Los_Angeles" but again the time is still not correct in the database...And yes I have also set the timezone in Wordpress correctly. So how can this be done?

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• Building IronRuby WPF GUIs

  - by Vlad

  This may be a silly question but I was under the impression that it was possible to use IronRuby and MS Visual Studio 2010 together to sort of build interfaces\edit XAML in one window and code ruby in the other? Is this only possible to do with C#, Basic and C++ ? I've browsed SO and seen some IronRuby snippets like this one: button1.click do |sender, args| MessageBox.show("Hello World!") end So it stands to reason you can create GUIs somehow, but is the visual gui creator not available for ironruby?

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• Java Swing: JWindow appears behind all other process windows, and will not disappear

  - by Kim Jong Woo

  I am using JWindow to display my splash screen during the application start up. however it will not appear in front of all windows as it should, and it will not disappear as well. import java.awt.BorderLayout; import java.awt.Color; import java.awt.Dimension; import java.awt.Font; import java.awt.Toolkit; import javax.swing.BorderFactory; import javax.swing.ImageIcon; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JWindow; public class MySplash { public static MySplash INSTANCE; private static JWindow jw; public MySplash(){ createSplash(); } private void createSplash() { jw = new JWindow(); JPanel content = (JPanel) jw.getContentPane(); content.setBackground(Color.white); // Set the window's bounds, centering the window int width = 328; int height = 131; Dimension screen = Toolkit.getDefaultToolkit().getScreenSize(); int x = (screen.width - width) / 2; int y = (screen.height - height) / 2; jw.setBounds(x, y, width, height); // Build the splash screen JLabel label = new JLabel(new ImageIcon("splash.jpg")); JLabel copyrt = new JLabel("SplashScreen Test", JLabel.CENTER); copyrt.setFont(new Font("Sans-Serif", Font.BOLD, 12)); content.add(label, BorderLayout.CENTER); content.add(copyrt, BorderLayout.SOUTH); Color oraRed = new Color(156, 20, 20, 255); content.setBorder(BorderFactory.createLineBorder(oraRed, 0)); } public synchronized static MySplash getInstance(){ if(INSTANCE==null){ INSTANCE = new MySplash(); } return INSTANCE; } public void showSplash(){ jw.setAlwaysOnTop(true); jw.toFront(); jw.setVisible(true); return; } public void hideSplash(){ jw.setAlwaysOnTop(false); jw.toBack(); jw.setVisible(false); return; } } So in my main class which extends JFrame, I call my splash screen by SwingUtilities.invokeLater(new Runnable(){ @Override public void run() { MySplash.getInstance().showSplash(); } }); However, the JWindow appears behind the all open instances of windows on my computer. Hiding the JWindow also doesn't work. SwingUtilities.invokeLater(new Runnable(){ @Override public void run() { MySplash.getInstance().hideSplash(); } });

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• AS3 colorTransform over multiple frames?

  - by user359519

  (Flash Professional, AS3) I'm working on a custom avatar system where you can select various festures and colors. For example, I have 10 hairstyles, and a colorPicker to change the color. mc_myAvatar has 10 frames. Each frame has a movieclip of a different hairstyle (HairStyle1, HairStyle2, etc.) Here's my code: var hairColor:ColorTransform; hairColor = mc_myAvatar.hair.colorLayer.transform.colorTransform; hairColor.color = 0xCCCC00; mc_myAvatar.hair.colorLayer.transform.colorTransform = hairColor; This correctly changes the initial color. I have a "nextHair" button to advance mc_myAvatar.hair to the next frame. When I click the button, I get an error message saying that I have a null object reference. I added a trace, and mc_myAvatar.hair.colorLayer is null on frame 2. Why??? I've clearly named HairStyle2 as "colorLayer" in frame 2. I think the problem is related to me using the same name for different classes/movieclips, but I don't know how to fix the problem... I added a square movieclip below my hairStyle movieclips, named the square "colorLevel", and deleted the name from my hairStyle clips. When I click the next button, the square correctly maintains the color from frame to frame. However, having a square doesn't do me much good. :( I tried converting the hairStyle layer to a mask. Doing this, however, results in yet another "null object" error - mc_myAvatar.hair.colorLayer is null after frame 1. I even tried "spanning" my colorLevel across all frames (no keyframes), thinking that this would give me just one movieclip to work with. No luck. Same error! What's going on, here? Why am I getting these null objects, when they are clearly defined in my movieclip? I'm also open to suggestions on a better way to do multiple frames and colors.

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• Access array of c-structs using Python ctypes

  - by sadris

  I have a C-function that allocates memory at the address passed to and is accessed via Python. The pointer contents does contain an array of structs in the C code, but I am unable to get ctypes to access the array properly beyond the 0th element. How can I get the proper memory offset to be able to access the non-zero elements? Python's ctypes.memset is complaining about TypeErrors if I try to use their ctypes.memset function. typedef struct td_Group { unsigned int group_id; char groupname[256]; char date_created[32]; char date_modified[32]; unsigned int user_modified; unsigned int user_created; } Group; int getGroups(LIBmanager * handler, Group ** unallocatedPointer); ############# python code below: class Group(Structure): _fields_ = [("group_id", c_uint), ("groupname", c_char*256), ("date_created", c_char*32), ("date_modified", c_char*32), ("user_modified", c_uint), ("user_created", c_uint)] myGroups = c_void_p() count = libnativetest.getGroups( nativePointer, byref(myGroups) ) casted = cast( myGroups, POINTER(Group*count) ) for x in range(0,count): theGroup = cast( casted[x], POINTER(Group) ) # this only works for the first entry in the array: print "~~~~~~~~~~" + theGroup.contents.groupname Related: Access c_char_p_Array_256 in Python using ctypes

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• jquery to toggle a label

  - by Juan Almonte

  How can I get the label to toggle show/hide? Below is my code and currently it is also displaying show. I would like it to toggle from show to hide and from hide back to show. when show is displayed the div will be hidden but when show is clicked the label will switch to hide and the div will be displayed and when hide is clicked the label will go back to show and the div will be hidden <html> <head> <title>jQuery test page</title> <script type="text/javascript" src="../scripts/jquery-1.4.2.js"></script> <script type="text/javascript"> $(document).ready(function() { $("#clickMe").click(function() { $("#textBox").toggle(); }); }); </script> </head> <body> <label id="clickMe">Show</label> <br /> <div id="textBox" style="display: none">This text will be toggled</div> </body> </html>

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• How to convert submitted form array to this array on php?

  - by drfanai

  Lets suppose i have the following array submitted by a html form: array( 'firstname' => array('Sara','Jim'), 'lastname' => array('Gibson','Jobs') ); What i wanna achieve is the following array: array( array( 'firstname' => 'sara', 'lastname' => 'Gibson' ), array( 'firstname' => 'Jim', 'lastname' => 'Jim' ) ); I need a function to automatically sort the array not manually by entering data but automatically processing array data.

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• How do I get the sequence of numbers in a sorted-set that are between two integers in clojure?

  - by Greg Rogers

  Say I have a sorted-set of integers, xs, and I want to retrieve all the integers in xs that are [x, y), ie. between x and y. I can do: (select #(and (>= % x) (< % y)) xs) But this is inefficient - O(n) when it could be O(log n), I expect the number of elements returned to be small. Using take-while and drop-while would let me exit once I've reached y, but I still can't jump to x efficiently. I am just learning clojure so here is how I would do it in C++: set<int>::iterator first = xs.lower_bound(x); set<int>::iterator last = xs.lower_bound(y); for (; first != last; ++first) // do something with *first Can I do this in clojure?

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• Use Html.RadioButtonFor and Html.LabelFor for the same Model but different values

  - by Marc

  I have this Razor Template <table> <tr> <td>@Html.RadioButtonFor(i => i.Value, "1")</td> <td>@Html.LabelFor(i => i.Value, "true")</td> </tr> <tr> <td>@Html.RadioButtonFor(i => i.Value, "0")</td> <td>@Html.LabelFor(i => i.Value, "false")</td> </tr> </table> That gives me this HTML <table> <tr> <td><input id="Items_1__Value" name="Items[1].Value" type="radio" value="1" /></td> <td><label for="Items_1__Value">true</label></td> </tr> <tr> <td><input checked="checked" id="Items_1__Value" name="Items[1].Value" type="radio" value="0" /></td> <td><label for="Items_1__Value">false</label></td> </tr> </table> So I have the ID Items_1__Value twice which is - of course - not good and does not work in a browser when I click on the second label "false" the first radio will be activated. I know I could add an own Id at RadioButtonFor and refer to that with my label, but that's not pretty good, is it? Especially because I'm in a loop and cannot just use the name "value" with an added number, that would be end up in multiple Dom Ids in my final HTML markup as well. Shouldn't be a good solution for this?

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• Modal dialog not working in chrome/explorer yet works in firefox

  - by Mike Z

  I have the following modal dialog click function $("#foo").click(function(){$("#bar").dialog({ width: 400, modal: true, resizable: false, buttons:{ "Save": function(){ $.post('remote_foo.php', $('#waka').serialize(), function(data){ $('#list').html(data);}) $(this).dialog("close"); $('.dial').val(''); $('.url').val('http://'); }, "cancel": function(){ $(this).dialog("close"); } }//end of buttons }).('open');//end of jquery dialog })// end of click function It works fine in firefox but to be honest i dont even think my click function is set up right. 1)Is this the proper way to open the dialog with a click. 2) is there a specific reason that this would not work in chrome/internet explorer? (This is the jquery ui)

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• Getting the last member of a group on an intermediary M2M

  - by rh0dium

  If we look at the existing docs, what is the best way to get the last member added? This is similar to this but what I want to do is to be able to do this. group = Group.objects.get(id=1) group.get_last_member_added() #This is by ('-date_added') <Person: FOO> I think the best way is through a manager but how do you do this on an intermediary model? class Person(models.Model): name = models.CharField(max_length=128) def __unicode__(self): return self.name class Group(models.Model): name = models.CharField(max_length=128) members = models.ManyToManyField(Person, through='Membership') def __unicode__(self): return self.name class Membership(models.Model): person = models.ForeignKey(Person) group = models.ForeignKey(Group) date_joined = models.DateField() invite_reason = models.CharField(max_length=64)

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• RSolr RequestError Solr Response Severe errors in solr configuration

  - by manalang

  I was reindexing my model when I suddenly shutdown my mac, When I try to reindex again using (Model_name).reindex in script/console I encountered an error that I haven't encountered before. RSolr::RequestError: Solr Response: Severe_errors_in_solr_configuration__Check_your_log_files_for_more_detailed_information_on_what_may_be_wrong__If_you_want_solr_to_continue_after_configuration_errors_change____abortOnConfigurationErrorfalseabortOnConfigurationError__in_null___javalangRuntimeException_javaioIOException_read_past_EOF__at_orgapachesolrcoreSolrCoregetSearcherSolrCorejava1068__at_orgapachesolrcoreSolrCoreinitSolrCorejava579__at_orgapachesolrcoreCoreContainer$InitializerinitializeCoreContainerjava137__at_orgapachesolrservletSolrDispatchFilterinitSolrDispatchFilterjava83__at_orgmortbayjettyservletFilterHolderdoStartFilterHolderjava99__at_orgmortbaycomponentAbstractLifeCyclestartAbstractLifeCyclejava40__at_orgmortbayjettyservletServletHandlerinitializeServletHandlerjava594__at_orgmortbayjettyservletContextstartContextContextjava139__at_orgmortbayjettywebappWebAppContextstartContextWebAppContextjava1218__at_orgmortbayjettyhandlerContextHandlerdoStartContextHandlerjava500__at_orgmortbayjettywebappWebAppContextdoStartWebAppContextjava448__at_orgmortbaycomponentAbstractLifeCyclestartAbstractLifeCyclejava40__at_orgmortbayjettyhandlerHandlerCollectiondoStartHandlerCollectionjava147__at_orgmortbayjettyhandlerContextHandlerCollectiondoStartContextHandlerCollectionjava161__at_orgmortbaycomponentAbstractLifeCyclestartAbstractLifeCyclejava40__at_orgmortbayjettyhandlerHandlerCollectiondoStartHandlerCollectionjava147__at_orgmortbaycomponentAbstractLifeCyclestartAbstractLifeCyclejava40__at_orgmortbayjettyhandlerHandlerWrapperdoStartHandlerWrapperjava117__at_orgmortbayjettyServerdoStartServerjava210__at_orgmortbaycomponentAbstractLifeCyclestartAbstractLifeCyclejava40__at_orgmortbayxmlXmlConfigurationmainXmlConfigurationjava929__at_sunreflectNativeMethodAccessorImplinvoke0Native_Method__at_sun from /usr/local/lib/ruby/gems/1.8/gems/rsolr-0.12.1/lib/rsolr/connection/requestable.rb:39:in `request' from /usr/local/lib/ruby/gems/1.8/gems/rsolr-0.12.1/lib/rsolr/client.rb:34:in `request' from /usr/local/lib/ruby/gems/1.8/gems/rsolr-0.12.1/lib/rsolr/client.rb:22:in `update' from /usr/local/lib/ruby/gems/1.8/gems/rsolr-0.12.1/lib/rsolr/client.rb:76:in `delete_by_query' from /usr/local/lib/ruby/gems/1.8/gems/sunspot-1.1.0/lib/sunspot/indexer.rb:55:in `remove_all' from /usr/local/lib/ruby/gems/1.8/gems/sunspot-1.1.0/lib/sunspot/session.rb:173:in `remove_all' from /usr/local/lib/ruby/gems/1.8/gems/sunspot-1.1.0/lib/sunspot/session.rb:173:in `each' from /usr/local/lib/ruby/gems/1.8/gems/sunspot-1.1.0/lib/sunspot/session.rb:173:in `remove_all' from /usr/local/lib/ruby/gems/1.8/gems/sunspot-1.1.0/lib/sunspot/session_proxy/abstract_session_proxy.rb:11:in `remove_all' from /usr/local/lib/ruby/gems/1.8/gems/sunspot-1.1.0/lib/sunspot.rb:414:in `remove_all' from /Users/cecilleann/Projects/dhire2/vendor/plugins/sunspot_rails-1.1.0/lib/sunspot/rails/searchable.rb:164:in `solr_remove_all_from_index' from /Users/cecilleann/Projects/dhire2/vendor/plugins/sunspot_rails-1.1.0/lib/sunspot/rails/searchable.rb:183:in `reindex' from (irb):6 Now I haven't been able to fix the error. Please help me. I can't move one. Thanks a lot in advance

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• ListView with Custom ArrayAdapter not updating

  - by Intelwalk

  I am currently trying to return a custom view of a textview, chrono, and checkbox. I have overriden the getView method but I am not sure if I did it correctly. I would appreciate some comments on the arrayadapter. It currently does not update in my application. Thanks! main java public class TaskTracker extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button addButton; addButton=(Button)findViewById(R.id.button1); ListView myListView= (ListView)findViewById(R.id.listView1); final EditText myEditText= (EditText)findViewById(R.id.editText1) ; //final ArrayList<String> taskitems = new ArrayList<String>(); final TTAdapterView aa = new TTAdapterView(this); // aa = new ArrayAdapter<String>(this, 0); myListView.setAdapter(aa); addButton.setOnClickListener(new OnClickListener(){ public void onClick(View v){ aa.add(myEditText.getText().toString()); //taskitems.add(count, myEditText.getText().toString()); aa.notifyDataSetChanged(); myEditText.setText(""); myEditText.requestFocus(); } }); } } ArrayAdapter public class TTAdapterView extends ArrayAdapter<String> { public View v; public TTAdapterView(Context context){ super(context,R.layout.row); } @Override public View getView(int position, View convertView, ViewGroup parent){ this.v = convertView; if(v==null){ LayoutInflater vi = (LayoutInflater)getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); v = vi.inflate(R.layout.row, null); } return v; }

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• Change style based on checkboxes w/jQuery

  - by santa

  I need to change the style of the entire row when a checkbox in that row is checked or unchecked. function myFunc() { if ($(".chkbx:checked").length) { $(this).parent().parent().css("background-color","red"); } else { $(this).parent().parent().css("background-color","green"); } } myFunc(); $(".chkbx").change(myFunc); <table> <tr> <td><input type="checkbox" class="chkbx" checked></td> <td>label 1</td> </tr> <tr> <td><input type="checkbox" class="chkbx" checked></td> <td>label 1</td> </tr> <tr> <td><input type="checkbox" class="chkbx" checked></td> <td>label 1</td> </tr> </table> I think I'm missing something here...

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• Entity Framework Batch Update and Future Queries

  - by pwelter34

  Entity Framework Extended Library A library the extends the functionality of Entity Framework. Features Batch Update and Delete Future Queries Audit Log Project Package and Source NuGet Package PM> Install-Package EntityFramework.Extended NuGet: http://nuget.org/List/Packages/EntityFramework.Extended Source: http://github.com/loresoft/EntityFramework.Extended Batch Update and Delete A current limitations of the Entity Framework is that in order to update or delete an entity you have to first retrieve it into memory. Now in most scenarios this is just fine. There are however some senerios where performance would suffer. Also, for single deletes, the object must be retrieved before it can be deleted requiring two calls to the database. Batch update and delete eliminates the need to retrieve and load an entity before modifying it. Deleting //delete all users where FirstName matches context.Users.Delete(u => u.FirstName == "firstname"); Update //update all tasks with status of 1 to status of 2 context.Tasks.Update( t => t.StatusId == 1, t => new Task {StatusId = 2}); //example of using an IQueryable as the filter for the update var users = context.Users .Where(u => u.FirstName == "firstname"); context.Users.Update( users, u => new User {FirstName = "newfirstname"}); Future Queries Build up a list of queries for the data that you need and the first time any of the results are accessed, all the data will retrieved in one round trip to the database server. Reducing the number of trips to the database is a great. Using this feature is as simple as appending .Future() to the end of your queries. To use the Future Queries, make sure to import the EntityFramework.Extensions namespace. Future queries are created with the following extension methods... Future() FutureFirstOrDefault() FutureCount() Sample // build up queries var q1 = db.Users .Where(t => t.EmailAddress == "[email protected]") .Future(); var q2 = db.Tasks .Where(t => t.Summary == "Test") .Future(); // this triggers the loading of all the future queries var users = q1.ToList(); In the example above, there are 2 queries built up, as soon as one of the queries is enumerated, it triggers the batch load of both queries. // base query var q = db.Tasks.Where(t => t.Priority == 2); // get total count var q1 = q.FutureCount(); // get page var q2 = q.Skip(pageIndex).Take(pageSize).Future(); // triggers execute as a batch int total = q1.Value; var tasks = q2.ToList(); In this example, we have a common senerio where you want to page a list of tasks. In order for the GUI to setup the paging control, you need a total count. With Future, we can batch together the queries to get all the data in one database call. Future queries work by creating the appropriate IFutureQuery object that keeps the IQuerable. The IFutureQuery object is then stored in IFutureContext.FutureQueries list. Then, when one of the IFutureQuery objects is enumerated, it calls back to IFutureContext.ExecuteFutureQueries() via the LoadAction delegate. ExecuteFutureQueries builds a batch query from all the stored IFutureQuery objects. Finally, all the IFutureQuery objects are updated with the results from the query. Audit Log The Audit Log feature will capture the changes to entities anytime they are submitted to the database. The Audit Log captures only the entities that are changed and only the properties on those entities that were changed. The before and after values are recorded. AuditLogger.LastAudit is where this information is held and there is a ToXml() method that makes it easy to turn the AuditLog into xml for easy storage. The AuditLog can be customized via attributes on the entities or via a Fluent Configuration API. Fluent Configuration // config audit when your application is starting up... var auditConfiguration = AuditConfiguration.Default; auditConfiguration.IncludeRelationships = true; auditConfiguration.LoadRelationships = true; auditConfiguration.DefaultAuditable = true; // customize the audit for Task entity auditConfiguration.IsAuditable<Task>() .NotAudited(t => t.TaskExtended) .FormatWith(t => t.Status, v => FormatStatus(v)); // set the display member when status is a foreign key auditConfiguration.IsAuditable<Status>() .DisplayMember(t => t.Name); Create an Audit Log var db = new TrackerContext(); var audit = db.BeginAudit(); // make some updates ... db.SaveChanges(); var log = audit.LastLog;

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• Code Camp 2011 – Summary

  - by hajan

  Waiting whole twelve months to come this year’s Code Camp 2011 event was something which all Microsoft technologies (and even non-Microsoft techs.) developers were doing in the past year. Last year’s success was enough big to be heard and to influence everything around our developer community and beyond. Code Camp 2011 was nothing else but a invincible success which will remain in our memory for a long time from now. Darko Milevski (president of MKDOT.NET UG and SharePoint MVP) said something interesting at the event keynote that up to now we were looking at the past by saying what we did… now we will focus on the future and how to develop our community more and more in the future days, weeks, months and I hope so for many years… Even though it was held only two days ago (26th of November 2011), I already feel the nostalgia for everything that happened there and for the excellent time we have spent all together. ORGANIZED BY ENTHUSIASTS AND EXPERTS Code Camp 2011 was organized by number of community enthusiasts and experts who have unselfishly contributed with all their free time to make the best of this event. The event was organized by a known community group called MKDOT.NET User Group, name of a user group which is known not only in Macedonia, but also in many countries abroad. Organization mainly consists of software developers, technical leaders, team leaders in several known companies in Macedonia, as well as Microsoft MVPs. SPEAKERS There were 24 speakers at five parallel tracks. At Code Camp 2011 we had two groups of speakers: Professional Experts in various technologies and Student Speakers. The new interesting thing here is the Student Speakers, which draw attention a lot, especially to other students who were interested to see what their colleagues are going to speak about and how do they use Microsoft technologies in different coding scenarios and practices, in different topics. From the rest of the professional speakers, there were 7 Microsoft MVPs: Two ASP.NET/IIS MVPs, Two C# MVPs, and One MVP in SharePoint, SQL Server and Exchange Server. I must say that besides the MVP Speakers, who definitely did a great job as always… there were other excellent speakers as well, which were speaking on various technologies, such as: Web Development, Windows Phone Development, XNA, Windows 8, Games Development, Entity Framework, Event-driven programming, SOLID, SQLCLR, T-SQL, e.t.c. SESSIONS There were 25 sessions mainly all related to Microsoft technologies, but ranging from Windows 8, WP7, ASP.NET till Games Development, XNA and Event-driven programming. Sessions were going in five parallel tracks named as Red, Yellow, Green, Blue and Student track. Five presentations in each track, each with level 300 or 400. More info MY SESSION (ASP.NET MVC Best Practices) I must say that from the big number of speaking engagements I have had, this was one of my best performances and definitely I have set new records of attendees at my sessions and probably overall. I spoke on topic ASP.NET MVC Best Practices, where I have shown tips, tricks, guidelines and best practices on what to use and what to avoid by developing with one of the best web development frameworks nowadays, ASP.NET MVC. I had approximately 350+ attendees, the hall was full so that there was no room for staying at feet. Besides .NET developers, there were a lot of other technology oriented developers, who has also received the presentation very well and I really hope I gave them reason to think about ASP.NET as one of the best options for web development nowadays (if you ask me, it’s the best one ;-)). I have included 10 tips in using ASP.NET MVC each of them followed by a demo. Besides these 10 tips, I have briefly introduced the concept of ASP.NET MVC for those that haven’t been working with the framework and at the end some bonus tips. I must say there was lot of laugh for some funny sentences I have stated, like “If you code ASP.NET MVC, girls will love you more” – same goes for girls, only replace girls with boys :). [LINK TO SESSION WILL GO HERE, ONCE SESSIONS ARE AVAILABLE ON MK CODECAMP WEBSITE] VOLUNTEERS Without strong organization, such events wouldn’t be able to gather hundreds of attendees at one place and still stay perfectly organized to the smallest details, without dedicated organization and volunteers. I would like to dedicate this space in my blog to them and to say one big THANK YOU for supporting us before the event and during the whole day in the event. With such young and dedicated volunteers, we couldn’t achieve anything but great results. THANK YOU EVERYONE FOR YOUR CONTRIBUTION! NETWORKING One of the main reasons why we do such events is to gather all professionals in one place. Networking is what everyone wants because through this way of networking, we can meet incredible people in one place. It is amazing feeling to share your knowledge with others and exchange thoughts on various topics. Meet and talk to interesting people. I have had very special moments with many attendees especially after my presentation. Special Thank You to all of them who come to meet me in person, whether to ask a question, say congrats for my session or simply meet me and just smile :)… everything counts! Thank You! TWITTER During the event, twitter was one of the most useful event-wide communication tool where everyone could tweet with hash tag #mkcodecamp or #mkdotnet and say what he/she wants to say about the current state and happenings at that moment… In my next blog post I will list the top craziest tweets that were posted at this event… FUTURE OF MKDOT.NET Having such strong community around MKDOT.NET, the future seems very bright. The initial plans are to have sub-groups in several technologies, however all these sub-groups will belong to the MKDOT.NET UG which will be, somehow, the HEAD of these sub-groups. We are doing this to provide better divisions by technologies and organize ourselves better since our community is very big, around 500 members in MKDOT.NET.We will have five sub-groups:- Web User Group (Lead:Hajan Selmani - me)- Mobile User Group (Lead: Filip Kerazovski)- Visual C# User Group (Lead: Vekoslav Stefanovski)- SharePoint User Group (Lead: Darko Milevski)- Dynamics User Group (Lead: Vladimir Senih) SUMMARY Online registered attendees: ~1.200 Event attendees: ~800 Number of members in organization: 40+ Organized by: MKDOT.NET User Group Number of tracks: 5 Number of speakers: 24 Number of sessions: 25 Event official website: http://codecamp.mkdot.net Total number of sponsors: 20 Platinum Sponsors: Microsoft, INETA, Telerik Place held: FON University City and Country: Skopje, Macedonia THANK YOU FOR BEING PART OF THE BEST EVENT IN MACEDONIA, CODE CAMP 2011. Regards, Hajan

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• First impressions of Scala

  - by Scott Weinstein

  I have an idea that it may be possible to predict build success/failure based on commit data. Why Scala? It’s a JVM language, has lots of powerful type features, and it has a linear algebra library which I’ll need later. Project definition and build Neither maven or the scala build tool (sbt) are completely satisfactory. This maven **archetype** (what .Net folks would call a VS project template) mvn archetype:generate `-DarchetypeGroupId=org.scala-tools.archetypes `-DarchetypeArtifactId=scala-archetype-simple `-DremoteRepositories=http://scala-tools.org/repo-releases `-DgroupId=org.SW -DartifactId=BuildBreakPredictor gets you started right away with “hello world” code, unit tests demonstrating a number of different testing approaches, and even a ready made `.gitignore` file - nice! But the Scala version is behind at v2.8, and more seriously, compiling and testing was painfully slow. So much that a rapid edit – test – edit cycle was not practical. So Lab49 colleague Steve Levine tells me that I can either adjust my pom to use fsc – the fast scala compiler, or use sbt. Sbt has some nice features It’s fast – it uses fsc by default It has a continuous mode, so  `> ~test` will compile and run your unit test each time you save a file It’s can consume (and produce) Maven 2 dependencies the build definition file can be much shorter than the equivalent pom (about 1/5 the size, as repos and dependencies can be declared on a single line) And some real limitations Limited support for 3rd party integration – for instance out of the box, TeamCity doesn’t speak sbt, nor does IntelliJ IDEA Steeper learning curve for build steps outside the default Side note: If a language has a fast compiler, why keep the slow compiler around? Even worse, why make it the default? I choose sbt, for the faster development speed it offers. Syntax Scala APIs really like to use punctuation – sometimes this works well, as in the following map1 |+| map2 The `|+|` defines a merge operator which does addition on the `values` of the maps. It’s less useful here: http(baseUrl / url >- parseJson[BuildStatus] sure you can probably guess what `>-` does from the context, but how about `>~` or `>+`? Language features I’m still learning, so not much to say just yet. However case classes are quite usefull, implicits scare me, and type constructors have lots of power. Community A number of projects, such as https://github.com/scalala and https://github.com/scalaz/scalaz are split between github and google code – github for the src, and google code for the docs. Not sure I understand the motivation here.

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• New HTML 5 input types in ASP.Net 4.5 Developer Preview

  - by sreejukg

  Microsoft has released developer previews for Visual Studio 2011 and .Net framework 4.5. There are lots of new features available in the developer preview. One of the most interested things for web developers is the support introduced for new HTML 5 form controls. The following are the list of new controls available in HTML 5 email url number range Date pickers (date, month, week, time, datetime, datetime-local) search color Describing the functionality for these controls is not in the scope of this article. If you want to know about these controls, refer the below URLs http://msdn.microsoft.com/en-us/magazine/hh547102.aspx http://www.w3schools.com/html5/html5_form_input_types.asp ASP.Net 4.5 introduced more possible values to the Text Mode attribute to cater the above requirements. Let us evaluate these. I have created a project in Visual Studio 2011 developer preview, and created a page named “controls.aspx”. In the page I placed on Text box control from the toolbox Now select the control and go to the properties pane, look at the TextMode attribute. Now you can see more options are added here than prior versions of ASP.Net. I just selected Email as TextMode. I added one button to submit my page. The screen shot of the page in Visual Studio 2011 designer is as follows See the corresponding markup <form id="form1" runat="server">     <div>         Enter your email:         <asp:TextBox ID="TextBox1" runat="server" TextMode="Email"></asp:TextBox     </div>     <asp:Button ID="Button1" runat="server" Text="Submit" /> </form> Now let me run this page, IE 9 do not have the support for new form fields. I browsed the page using Firefox and the page appears as below. From the source of the rendered page, I saw the below markup for my email textbox <input name="TextBox1" type="email" id="TextBox1" /> Try to enter an invalid email and you will see the browser will ask you to enter a valid one by default. When rendered in non-supported browsers, these fields are behaving just as normal text boxes. So make sure you are using validation controls with these fields. See the browser support compatability matrix with these controls with various browser vendors. ASP.Net 4.5 introduced the support for these new form controls. You can build interactive forms using the newly added controls, keeping in mind that you need to validate the data for non-supported browsers.

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• Novo Suporte para Combinação e Minificação de Arquivos JavaScript e CSS (Série de posts sobre a ASP.NET 4.5)

  - by Leniel Macaferi

  Este é o sexto post de uma série de posts que estou escrevendo sobre a ASP.NET 4.5. Os próximos lançamentos do .NET e Visual Studio incluem vários novos e ótimos recursos e capacidades. Com a ASP.NET 4.5 você vai ver um monte de melhorias realmente emocionantes em formulários da Web ( Web Forms ) e MVC - assim como no núcleo da base de código da ASP.NET, no qual estas tecnologias são baseadas. O post de hoje cobre um pouco do trabalho que estamos realizando para adicionar suporte nativo para combinação e minificação de arquivos JavaScript e CSS dentro da ASP.NET - o que torna mais fácil melhorar o desempenho das aplicações. Este recurso pode ser utilizado por todas as aplicações ASP.NET, incluindo tanto a ASP.NET MVC quanto a ASP.NET Web Forms. Noções básicas sobre Combinação e Minificação Como mais e mais pessoas usando dispositivos móveis para navegar na web, está se tornando cada vez mais importante que os websites e aplicações que construímos tenham um bom desempenho neles. Todos nós já tentamos carregar sites em nossos smartphones - apenas para, eventualmente, desistirmos em meio à frustração porque os mesmos são carregados lentamente através da lenta rede celular. Se o seu site/aplicação carrega lentamente assim, você está provavelmente perdendo clientes em potencial por causa do mau desempenho/performance. Mesmo com máquinas desktop poderosas, o tempo de carregamento do seu site e o desempenho percebido podem contribuir enormemente para a percepção do cliente. A maioria dos websites hoje em dia são construídos com múltiplos arquivos de JavaScript e CSS para separar o código e para manter a base de código coesa. Embora esta seja uma boa prática do ponto de vista de codificação, muitas vezes isso leva a algumas consequências negativas no tocante ao desempenho geral do site. Vários arquivos de JavaScript e CSS requerem múltiplas solicitações HTTP provenientes do navegador - o que pode retardar o tempo de carregamento do site.  Exemplo Simples A seguir eu abri um site local no IE9 e gravei o tráfego da rede usando as ferramentas do desenvolvedor nativas do IE (IE Developer Tools) que podem ser acessadas com a tecla F12. Como mostrado abaixo, o site é composto por 5 arquivos CSS e 4 arquivos JavaScript, os quais o navegador tem que fazer o download. Cada arquivo é solicitado separadamente pelo navegador e retornado pelo servidor, e o processo pode levar uma quantidade significativa de tempo proporcional ao número de arquivos em questão. Combinação A ASP.NET está adicionando um recurso que facilita a "união" ou "combinação" de múltiplos arquivos CSS e JavaScript em menos solicitações HTTP. Isso faz com que o navegador solicite muito menos arquivos, o que por sua vez reduz o tempo que o mesmo leva para buscá-los. A seguir está uma versão atualizada do exemplo mostrado acima, que tira vantagem desta nova funcionalidade de combinação de arquivos (fazendo apenas um pedido para JavaScript e um pedido para CSS): O navegador agora tem que enviar menos solicitações ao servidor. O conteúdo dos arquivos individuais foram combinados/unidos na mesma resposta, mas o conteúdo dos arquivos permanece o mesmo - por isso o tamanho do arquivo geral é exatamente o mesmo de antes da combinação (somando o tamanho dos arquivos separados). Mas note como mesmo em uma máquina de desenvolvimento local (onde a latência da rede entre o navegador e o servidor é mínima), o ato de combinar os arquivos CSS e JavaScript ainda consegue reduzir o tempo de carregamento total da página em quase 20%. Em uma rede lenta a melhora de desempenho seria ainda maior. Minificação A próxima versão da ASP.NET também está adicionando uma nova funcionalidade que facilita reduzir ou "minificar" o tamanho do download do conteúdo. Este é um processo que remove espaços em branco, comentários e outros caracteres desnecessários dos arquivos CSS e JavaScript. O resultado é arquivos menores, que serão enviados e carregados no navegador muito mais rapidamente. O gráfico a seguir mostra o ganho de desempenho que estamos tendo quando os processos de combinação e minificação dos arquivos são usados ??em conjunto: Mesmo no meu computador de desenvolvimento local (onde a latência da rede é mínima), agora temos uma melhoria de desempenho de 40% a partir de onde originalmente começamos. Em redes lentas (e especialmente com clientes internacionais), os ganhos seriam ainda mais significativos. Usando Combinação e Minificação de Arquivos dentro da ASP.NET A próxima versão da ASP.NET torna realmente fácil tirar proveito da combinação e minificação de arquivos dentro de projetos, possibilitando ganhos de desempenho como os que foram mostrados nos cenários acima. A forma como ela faz isso, te permite evitar a execução de ferramentas personalizadas/customizadas, como parte do seu processo de construção da aplicação/website - ao invés disso, a ASP.NET adicionou suporte no tempo de execução/runtime para que você possa executar a combinação/minificação dos arquivos dinamicamente (cacheando os resultados para ter certeza de que a performance seja realmente satisfatória). Isto permite uma experiência de desenvolvimento realmente limpa e torna super fácil começar a tirar proveito destas novas funcionalidades. Vamos supor que temos um projeto simples com 4 arquivos JavaScript e 6 arquivos CSS: Combinando e Minificando os Arquivos CSS Digamos que você queira referenciar em uma página todas as folhas de estilo que estão dentro da pasta "Styles" mostrada acima. Hoje você tem que adicionar múltiplas referências para os arquivos CSS para obter todos eles - o que se traduziria em seis requisições HTTP separadas: O novo recurso de combinação/minificação agora permite que você combine e minifique todos os arquivos CSS da pasta Styles - simplesmente enviando uma solicitação de URL para a pasta (neste caso, "styles"), com um caminho adicional "/css" na URL. Por exemplo:    Isso fará com que a ASP.NET verifique o diretório, combine e minifique os arquivos CSS que estiverem dentro da pasta, e envie uma única resposta HTTP para o navegador com todo o conteúdo CSS. Você não precisa executar nenhuma ferramenta ou pré-processamento para obter esse comportamento. Isso te permite separar de maneira limpa seus estilos em arquivos CSS separados e condizentes com cada funcionalidade da aplicação mantendo uma experiência de desenvolvimento extremamente limpa - e mesmo assim você não terá um impacto negativo de desempenho no tempo de execução da aplicação. O designer do Visual Studio também vai honrar a lógica de combinação/minificação - assim você ainda terá uma experiência WYSWIYG no designer dentro VS. Combinando e Minificando os Arquivos JavaScript Como a abordagem CSS mostrada acima, se quiséssemos combinar e minificar todos os nossos arquivos de JavaScript em uma única resposta, poderíamos enviar um pedido de URL para a pasta (neste caso, "scripts"), com um caminho adicional "/js":   Isso fará com que a ASP.NET verifique o diretório, combine e minifique os arquivos com extensão .js dentro dele, e envie uma única resposta HTTP para o navegador com todo o conteúdo JavaScript. Mais uma vez - nenhuma ferramenta customizada ou etapas de construção foi necessária para obtermos esse comportamento. Este processo funciona em todos os navegadores. Ordenação dos Arquivos dentro de um Pacote Por padrão, quando os arquivos são combinados pela ASP.NET, eles são ordenados em ordem alfabética primeiramente, exatamente como eles são mostrados no Solution Explorer. Em seguida, eles são automaticamente reorganizados de modo que as bibliotecas conhecidas e suas extensões personalizadas, tais como jQuery, MooTools e Dojo sejam carregadas antes de qualquer outra coisa. Assim, a ordem padrão para a combinação dos arquivos da pasta Scripts, como a mostrada acima será: jquery-1.6.2.js jquery-ui.js jquery.tools.js a.js Por padrão, os arquivos CSS também são classificados em ordem alfabética e depois são reorganizados de forma que o arquivo reset.css e normalize.css (se eles estiverem presentes na pasta) venham sempre antes de qualquer outro arquivo. Assim, o padrão de classificação da combinação dos arquivos da pasta "Styles", como a mostrada acima será: reset.css content.css forms.css globals.css menu.css styles.css A ordenação/classificação é totalmente personalizável, e pode ser facilmente alterada para acomodar a maioria dos casos e qualquer padrão de nomenclatura que você prefira. O objetivo com a experiência pronta para uso, porém, é ter padrões inteligentes que você pode simplesmente usar e ter sucesso com os mesmos. Qualquer número de Diretórios/Subdiretórios é Suportado No exemplo acima, nós tivemos apenas uma única pasta "Scripts" e "Styles" em nossa aplicação. Isso funciona para alguns tipos de aplicação (por exemplo, aplicações com páginas simples). Muitas vezes, porém, você vai querer ter múltiplos pacotes/combinações de arquivos CSS/JS dentro de sua aplicação - por exemplo: um pacote "comum", que tem o núcleo dos arquivos JS e CSS que todas as páginas usam, e então arquivos específicos para páginas ou seções que não são utilizados globalmente. Você pode usar o suporte à combinação/minificação em qualquer número de diretórios ou subdiretórios em seu projeto - isto torna mais fácil estruturar seu código de forma a maximizar os benefícios da combinação/minificação dos arquivos. Cada diretório por padrão pode ser acessado como um pacote separado e endereçável através de uma URL.  Extensibilidade para Combinação/Minificação de Arquivos O suporte da ASP.NET para combinar e minificar é construído com extensibilidade em mente e cada parte do processo pode ser estendido ou substituído. Regras Personalizadas Além de permitir a abordagem de empacotamento - baseada em diretórios - que vem pronta para ser usada, a ASP.NET também suporta a capacidade de registrar pacotes/combinações personalizadas usando uma nova API de programação que estamos expondo.  O código a seguir demonstra como você pode registrar um "customscript" (script personalizável) usando código dentro da classe Global.asax de uma aplicação. A API permite que você adicione/remova/filtre os arquivos que farão parte do pacote de maneira muito granular:     O pacote personalizado acima pode ser referenciado em qualquer lugar dentro da aplicação usando a referência de <script> mostrada a seguir:     Processamento Personalizado Você também pode substituir os pacotes padrão CSS e JavaScript para suportar seu próprio processamento personalizado dos arquivos do pacote (por exemplo: regras personalizadas para minificação, suporte para Saas, LESS ou sintaxe CoffeeScript, etc). No exemplo mostrado a seguir, estamos indicando que queremos substituir as transformações nativas de minificação com classes MyJsTransform e MyCssTransform personalizadas. Elas são subclasses dos respectivos minificadores padrão para CSS e JavaScript, e podem adicionar funcionalidades extras:     O resultado final desta extensibilidade é que você pode se plugar dentro da lógica de combinação/minificação em um nível profundo e fazer algumas coisas muito legais com este recurso. Vídeo de 2 Minutos sobre Combinação e Minificacão de Arquivos em Ação Mads Kristensen tem um ótimo vídeo de 90 segundo (em Inglês) que demonstra a utilização do recurso de Combinação e Minificação de Arquivos. Você pode assistir o vídeo de 90 segundos aqui. Sumário O novo suporte para combinação e minificação de arquivos CSS e JavaScript dentro da próxima versão da ASP.NET tornará mais fácil a construção de aplicações web performáticas. Este recurso é realmente fácil de usar e não requer grandes mudanças no seu fluxo de trabalho de desenvolvimento existente. Ele também suporta uma rica API de extensibilidade que permite a você personalizar a lógica da maneira que você achar melhor. Você pode facilmente tirar vantagem deste novo suporte dentro de aplicações baseadas em ASP.NET MVC e ASP.NET Web Forms. Espero que ajude, Scott P.S. Além do blog, eu uso o Twitter para disponibilizar posts rápidos e para compartilhar links.Lidar com o meu Twitter é: @scottgu Texto traduzido do post original por Leniel Macaferi. google_ad_client = "pub-8849057428395760"; /* 728x90, created 2/15/09 */ google_ad_slot = "4706719075"; google_ad_width = 728; google_ad_height = 90;

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• Reflections on Life

  - by MOSSLover

  I haven’t written a blog post in a while.  I understand there is blog neglect going on, but there is a lot going on in my life.  I am trying really hard to embrace the change and roll with everything thrown my way.  I had a really hard year it was not my best and it was not my worst.  I cannot say it was entirely hard, because January 1st I received the MVP Award.  If you know me you know the three things that happened starting in August, but if you really know me it was miserable for a substantial period of time prior to August.  There was some personal life issues I neglected to deal with that came into a headway.  Anyway I’d like to think that as of today I am doing much better.  I finally went to Paris and London.  I found out I love Paris and Nottingham.  I think that London is something I need to visit a few more times.  I would love to go back to the UK and France.  I think I’d love to live overseas someday, but not anytime soon. The past few weeks were like a whirlwind experience.  I felt like I had been sitting around for months just waiting for this trip and the big move.  Maybe it was something I was waiting to do for several years.  I needed a big change.  I needed to get unstuck.  I feel like August, however horrible it was, helped me get to the point where I am somewhere happy.  For at least two years I have been miserable outside of my work (community and otherwise).  I was just downright unhappy.  One of my coworkers said that my tweets were just horrible this past year.  Depressing might I add.  I agree they were incredibly depressing for the past several years.  But things are on an upturn.  I decided a month or so ago that I was going to do all the things I have wanted to do without looking back.  So I dove into this trip and into this move to NYC head first.  I was scared for a bit and I didn’t think it would come through.  Everyone friend-wise and coworker-wise has helped me accomplish this great feat.  I am now a New Yorker and as of January 1st 100% living in the city. Thank you for those who have checked up on me.  Thank you for those who listened to all my problems and continue to do so.  Thank you to everyone who has helped me through this really terrible time.  You guys mean the world to me.  You are my friends.  Some of you I have not met and some of you I barely know.  I have been to a lot of events where people just walked up to me and asked me if I was doing ok.  I will continue to keep moving forward one foot in front of the other.  If I ever get so down again please remind me about this year.  I hope to see you all in the upcoming year as I attend more events.  Have a good night or a good morning or a good afternoon.  I will catch you all later. Technorati Tags: Life,2011,Disaster Year,Happinness

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• Custom Model Binding of IEnumerable Properties in ASP.Net MVC 2

  - by Doug Lampe

  MVC 2 provides a GREAT feature for dealing with enumerable types.  Let's say you have an object with a parent/child relationship and you want to allow users to modify multiple children at the same time.  You can simply use the following syntax for any indexed enumerables (arrays, generic lists, etc.) and then your values will bind to your enumerable model properties. 1: <% using (Html.BeginForm("TestModelParameter", "Home")) 2: { %> 3: < table > 4: < tr >< th >ID</th><th>Name</th><th>Description</th></tr> 5: <% for (int i = 0; i < Model.Items.Count; i++) 6: { %> 7: < tr > 8: < td > 9: <%= i %> 10: </ td > 11: < td > 12: <%= Html.TextBoxFor(m => m.Items[i].Name) %> 13: </ td > 14: < td > 15: <%= Model.Items[i].Description %> 16: </ td > 17: </ tr > 18: <% } %> 19: </ table > 20: < input type ="submit" /> 21: <% } %> Then just update your model either by passing it into your action method as a parameter or explicitly with UpdateModel/TryUpdateModel. 1: public ActionResult TestTryUpdate() 2: { 3: ContainerModel model = new ContainerModel(); 4: TryUpdateModel(model); 5:   6: return View("Test", model); 7: } 8:   9: public ActionResult TestModelParameter(ContainerModel model) 10: { 11: return View("Test", model); 12: } Simple right?  Well, not quite.  The problem is the DefaultModelBinder and how it sets properties.  In this case our model has a property that is a generic list (Items).  The first bad thing the model binder does is create a new instance of the list.  This can be fixed by making the property truly read-only by removing the set accessor.  However this won't help because this behaviour continues.  As the model binder iterates through the items to "set" their values, it creates new instances of them as well.  This means you lose any information not passed via the UI to your controller so in the examplel above the "Description" property would be blank for each item after the form posts. One solution for this is custom model binding.  I have put together a solution which allows you to retain the structure of your model.  Model binding is a somewhat advanced concept so you may need to do some additional research to really understand what is going on here, but the code is fairly simple.  First we will create a binder for the parent object which will retain the state of the parent as well as some information on which children have already been bound. 1: public class ContainerModelBinder : DefaultModelBinder 2: { 3: /// <summary> 4: /// Gets an instance of the model to be used to bind child objects. 5: /// </summary> 6: public ContainerModel Model { get; private set; } 7:   8: /// <summary> 9: /// Gets a list which will be used to track which items have been bound. 10: /// </summary> 11: public List<ItemModel> BoundItems { get; private set; } 12:   13: public ContainerModelBinder() 14: { 15: BoundItems = new List<ItemModel>(); 16: } 17:   18: protected override object CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType) 19: { 20: // Set the Model property so child binders can find children. 21: Model = base.CreateModel(controllerContext, bindingContext, modelType) as ContainerModel; 22:   23: return Model; 24: } 25: } Next we will create the child binder and have it point to the parent binder to get instances of the child objects.  Note that this only works if there is only one property of type ItemModel in the parent class since the property to find the item in the parent is hard coded. 1: public class ItemModelBinder : DefaultModelBinder 2: { 3: /// <summary> 4: /// Gets the parent binder so we can find objects in the parent's collection 5: /// </summary> 6: public ContainerModelBinder ParentBinder { get; private set; } 7: 8: public ItemModelBinder(ContainerModelBinder containerModelBinder) 9: { 10: ParentBinder = containerModelBinder; 11: } 12:   13: protected override object CreateModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Type modelType) 14: { 15: // Find the item in the parent collection and add it to the bound items list. 16: ItemModel item = ParentBinder.Model.Items.FirstOrDefault(i => !ParentBinder.BoundItems.Contains(i)); 17: ParentBinder.BoundItems.Add(item); 18: 19: return item; 20: } 21: } Finally, we will register these binders in Global.asax.cs so they will be used to bind the classes. 1: protected void Application_Start() 2: { 3: AreaRegistration.RegisterAllAreas(); 4:   5: ContainerModelBinder containerModelBinder = new ContainerModelBinder(); 6: ModelBinders.Binders.Add(typeof(ContainerModel), containerModelBinder); 7: ModelBinders.Binders.Add(typeof(ItemModel), new ItemModelBinder(containerModelBinder)); 8:   9: RegisterRoutes(RouteTable.Routes); 10: } I'm sure some of my fellow geeks will comment that this could be done more efficiently by simply rewriting some of the methods of the default model binder to get the same desired behavior.  I like my method shown here because it extends the binder class instead of modifying it so it minimizes the potential for unforseen problems. In a future post (if I ever get around to it) I will explore creating a generic version of these binders.

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