Skip to main content

How to get collections on viewmodel on postback in MVC

In mvc most of the people will face problem how to bind view model list while post request. If a partial control is binding with a list and want to preserve the user input with view model list, most common issue is id/name is same. If the Id/Name are different only MVC engine can bind it with the model.

Please see the below example

Build the view/partial view in the following way. By keeping a row counter means all items will have unique names.

Suppose this partial view is coming inside a View Called MethodName.ASPX and is included inside the

Main Page


using html.beginform()
[httpGet]

{
<%html.dropdownlist(model=>model.Test, new {onclick=Test(<%=model.Id%>);});
<.div id="dvPopulatePartialViewWithList"></.div>
}


Javascript function Test


function Test(id)
{
 $.ajax({
        type: "Get",
        data: "Id=" + Id,
        url: '/MyController/GetPartialViewListById',
        success: function (result) {
            $('#dvPopulatePartialViewWithList').html(result);
        }
    });
}


Controller Method


public actionresult GetPartialViewListById(int Id)
{
 try
{
  List list=GetListById(Id);

return renderPartial("MyPartialView",list);
}
catch(Exception ex)
{
throw new exception("error",ex);
}
}

PartialView   MyPartialView


<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl>" %>
<%@ Import Namespace="External_ViewModel" %>

<%  int rowCounter = 0; //Keep track of unique value for binding to model list
%>
   

<%
           foreach (var model in Model)
           {
           
<%: Html.ValidationSummary(true)%>
<%: Html.Hidden("[" + rowCounter + "].Id", model.Id)%>
<%: Html.Hidden("[" + rowCounter + "].Name", Model.Name)%>

    <%= model.nameOfItem%>
    [
    <%= cav.Item%>
    ]



    <%: Html.TextBox("[" + rowCounter + "].Value", model.Value, new { Style = "width:140px;" })%>
 
    <%: Html.ValidationMessage("[" + rowCounter + "].Value", model.Value)%>
 
<% ++rowCounter;
           }  //end foreach  Loop
%>

In Controller create the action like this


[httpPost]
 public ActionResult MethodName(ViewModel model, List resultList)

        {
// when you submit the form resultList will have binded values
}

Comments

Popular posts from this blog

How to write secure mvc application using encrypting URL

There are lots ways available to write the secure Mvc application. In my experience I came across lots of secure application in public facing. I want to tell about some of the mechanism I followed.
1- encrypting the URL Parameters and preserving id's encrypted on the client side
1- I always make sure if I pass Id or any sensitive data into the view always make sure it's encrypted. By doing so make sure if we forced to use HTML.hidden or HTML.hidden for have the encrypted values, in action link if I pass any parameters from the client side (eg:- edit or create or navigating between different actions we can make sure that all the values are encrypted)
During the design of the actions results if it's http get I usually encrypt the sensitive data
[httpget]
Public actionresult display()
{
TestModel testModel=new TestModel();
testModel.id= encrypt(id);
Return View(testModel);
}
[httppost]
Public ActionResult Display(string id)
{
Guid d_id= new Guid(decrypt(id));
// do operati…

How to add a stored procedure in Entity Framework

Step1- Open the .edmx file
Step2- Right click in .edmx file and select Update Model from Database


Step3- Select Add tab, select Stored Procedures and select the procedure you want to add and click finish as shown in below figure a

Step4- Build the Entity Project to make sure nothing is broke

Step5- Right click on .edmx file and  select Model Browser



Step6- Model Browser Popup will appear as  below figure. Click on the Strored Procedures in PricingToolModel.Stroe and click the newly added SP (it will appear here)
Step7- The Add Function Import screen will appear

Based on the return we can set up.

If you are returning a multiple column Click on the Get Column Information First, then click the new Complex Type. After that you can see the Return of Collection will select the Complex and a complex type is generated by EF

If its returning scalar you can select which return type like int, string etc...

If its return entitty (means table) please select the correct table from the list..

Click…

Compiled Query- Improve the performance of Linq to Entity Query

Most of the small or medium IT firms are using the Entity framework for the Data Access layer (DAL). If we write a complex linq to Entity queries performance will always be an issue. But with the Compiled Query Performance can be improved. This below definitions are from MSDN and more details can be found on the MSDN Link that is at the end of this post 


         When you have an application that executes structurally similar queries many times in the Entity Framework, you can frequently increase performance by compiling the query one time and executing it several times with different parameters. For example, an application might have to retrieve all the QuoteRevision for a particular quotelineStatus, the quotelinestatus is specified at runtime. LINQ to Entities supports using compiled queries for this purpose.


              The compiled query class provides compilation and caching of queries for reuse. Conceptually, this class contains aCompiledQuery'sCompilemethod with several ove…