Entity Framework 4.3 released.

Check out what's new in the EF 4.3 - http://blogs.msdn.com/b/adonet/archive/2012/02/09/ef-4-3-released.aspx

Multiple Submit button on a single MVC form

Leaving the question of weather this is a good practice or not, there is a way to have multiple submit buttons on a single form. Clicking on any of the buttons will post to the same action, so how do you tell which one was clicked. On your View:

@using (Html.BeginForm())
{
 //other fields here.....
 
 
}

On your controller that the form posts to:

[HttpPost]
public ActionResult Profile(Model model,string submitButton)
{
  Member member = new Member();
  switch (submitButton)
  {
     case "Save1": //do something;
        break;
     case "Save2": //do something;
        break;
  }
   return View(model);
}

Dynamically adding a collection of objects in a MVC view

In one of my projects I needed to dynamically display fields to enter information for a collection of objects. Specifically speaking I had a POCO "User" class with FK to a POCO "Child" class. I needed a way to generate text boxes based on how many kids a user had. This involves several steps and here's what I had to do.

1. Create a partial view with the fields you need to capture the info for a "Child"

@{
    var seed = ViewBag.Seed;
      
    

        @{
            @*MVC renders fields for a collection by appending an index, which I am setting up below*@
              var ageIdText = "Children_" + seed + "__Age";
              var ageNameText = "Children[" + seed + "].Age";
              var genderIdText = "Children_" + seed + "__Gender";
              var genderNameText = "Children[" + seed + "].Gender";
              var deleteIdText = "Children_" + seed + "__Delete";
              var deleteNameText = "Children[" + seed + "].Delete";
            }
            Child's Gender
        
            
            Female
            Male
          
        Child's Age
        
        
        
        Remove
    
    
    
    
             
    
    
    }

MVC renders controls for collections by attaching an index for the collection. I had to code this in to render based on the number of controls that need to be displayed. Ex: the age text field will be Children_[1]__Age and so forth. I will explain the reason for having a delete field a little later. 2. Create an action in the controller that will return the partial view

public ActionResult RenderChildren(int? id, int? seed, string viewType)
        {
            //if no of children to be rendered in the view was not send in the request url, then render only one child
            if (id.HasValue)
                ViewBag.Children = id;
            else
                ViewBag.Children = 1;

            //if the collection index was not indicated, then start rendering the controls from 0. 
            //This will come in handy when there are already controls on the page and we want to add more.
            if (seed.HasValue)
                ViewBag.Seed = seed;
            else
                ViewBag.Seed = 0;
            return PartialView(viewType);
        }

It is important to keep track on the index for the collection, or you will get unexpected results.

3. Create the javascript that will call the action above from another control. ex: onclick event of a link that should add the control for adding a "Child"

function addChild(method,container,type) {
    var noofChild = $(container).find('.mark-for-delete').length;
    $.get('/account/'+method+'?seed=' + (noofChild)+"&viewtype="+type, function (template) { $(container).append(template); });
}

4. Call the javascript

Add a child

function deleteChildren(element, deleteElement) {
    $container = $(element).parent();
    $container.find(deleteElement).val('True');
    $container.hide();
}

This will take care of dynamically rendering the required number of fields for "Child" 5. Handling the deletes - I also needed to provide the user to delete existing fields

Remove

To handle the delete I need some more javascript code that will add some value to the hidden field that I added to my partial view. This value can then be picked up via the model while updating the database. I do have a property in the "Child" POCO class for setting the delete value. This field is not mapped to the database.

The different WCF bindings

It's awesome that WCF support all the different bindings and protocols. Connect with multiple apps running different protocols all with the same code. Here's a list of all the different bindings that WCF support. I snagged this from - http://msdn.microsoft.com/en-us/library/bb310550.aspx. This link is a highly recommended read - has info on speed comparisons etc.

Bindings	Description
BasicHttpBinding	A binding that is suitable for communication with WS-Basic Profile conformant Web Services like ASMX-based services. This binding uses HTTP as the transport and Text/XML as the message encoding.
WSHttpBinding	A secure and interoperable binding that is suitable for non-duplex service contracts.
WSDualHttpBinding	A secure and interoperable binding that is suitable for duplex service contracts or communication through SOAP intermediaries.
WSFederationHttpBinding	A secure and interoperable binding that supports the WS-Federation protocol, enabling organizations that are in a federation to efficiently authenticate and authorize users.
NetTcpBinding	A secure and optimized binding suitable for cross-machine communication between WCF applications
NetNamedPipeBinding	A secure, reliable, optimized binding that is suitable for on-machine communication between WCF applications.
NetMsmqBinding	A queued binding that is suitable for cross-machine communication between WCF applications.
NetPeerTcpBinding	A binding that enables secure, multi-machine communication.
MsmqIntegrationBinding	A binding that is suitable for cross-machine communication between a WCF application and existing MSMQ applications.