Remove ViewEngines that are not used : An ASP.NET MVC performance tip

Today, I am writing a small post on ASP.NET MVC that will help in performance of ASP.NET MVC application. So lets discuss it in detail.

Whenever we create an ASP.NET MVC application it allows us to select a View Engine Razor for the application as.

select View engine

Here we selected Razor and this is selected by default as well.

But when applications run, it loads multiple view engines and we use only one view engine normally that is selected while application creation. We can prove it many ways

1) Let’s see the collection ViewEngines in Global.asax. It shows as while debugging.

firstallThe above clearly shows that it contains two View Engines while we selected Razor View Engine while creating application.

2) To prove it another way, As we know when we use Razor View Engine then views extension is .cshtml and for WebForms view engine, it is .aspx. So lets say we created a controller and it has a method like

public ActionResult Index()
{
    return View();
}

And we did not created any view accordingly. Now when we run the applications it throws the following error

serachedviews

It tries to find the View but could not find. It also shows what file names and where does it try to find. If we see the above screenshot then we find that it tries to look files with extension .cshtml/.vbhtml and .aspx/.ascx as well, where .aspx/.ascx is used in case of web-forms view engine. And we selected razor View engine while application creation. It simply shows that it loads two view  engines which is not required.

Solution : Add the following code in the method Application_Start in Global.asax

// Removes all the view engine
ViewEngines.Engines.Clear();

// Add View Engine that we are ging to use. Here I am using Razor View Engine
ViewEngines.Engines.Add(new RazorViewEngine());

Now after making the above changes, it loads only the added ( here Razor) view engine.

Now we can check the scenario discussed in point 2 and now see the page

afterremovinNow it tries to find only .cshtml/.vbhtml files.

We should use the above logic and because there is no use loading all the view engines in memory if we are not using .

Hope you all find it useful and use it in your projects.

Cheers,
Brij

The requested content appears to be script and will not be served by the static file handler. : A Solution

Today, I faced one issue while working on one sample . And could not find solution in one go and error shown was not intuitive enough.

First let me share my environment. Windows 8 (64 bit), Visual Studio 2012, IIS8

I created an ASP.NET 2.0 web service using Visual Studio 2012 directly at IIS8. But as soon as, I tried to access my web service via browser I found the following error

ErrorAs you can see from the error, it does not point to any cause.

For this error there could be one issue that IIS is not registered with ASP.NET. So to register it, I opened the command prompt with run as administrator and navigated to the folder C:\Windows\Microsoft.NET\Framework\v2.0.50727. I navigated to framework version 2.0 because I was accessing the ASP.NET 2.0 webservice. Now I required to run the following command

aspnet_regiis -i

But as soon as I run the above command, I faced another error

errorcmd

Later, I found that my Operating System (Windows 8) that I am running is of 64 bit version. So again navigated 64bit version executable and it ran successfully

successfullyRanSo you can see above the message “Finished installing ASP.NET <2.0.50727>”.  Here in the above pic, if you see the red encircled area, I have ran here 64 bit version executable.

Also note, this issue arises only if you installed the IIS after installing Visual Studio.

Hope this would save lot of time of yours.

Thanks,
Brij

How to access the input control’s data at Server side during Client Callback : A useful trick

Client callback is one way to update the webpage without performing the full page postback. It maintains the Client state while updating the Webpage. During Client callback the webpage runs through modifies version of Page Life Cycle.

The LifeCycle of a page in Client Call Back is  as

Page Lifecycle iin Callback

If you want to learn  more about Client Callback, click here.

But the main drawback of  Client Callback, The input data is not posted from Client to Server. Also,  It does not maintain the view state during partial postback as you can see the Page life cycle of Client callbak it is not saved or SaveViewState event is not fired.

Lets see it with an example.

I have created a simple form to collect some information of an person data. And it has a submit button, which initiates a Callback. As

 <table>
 <tr><td><asp:Label id="lblFName" runat="server" Text="First Name" /> </td>
 <td><asp:TextBox ID="tbFName" runat="server"></asp:TextBox></td></tr><tr>
 <td><asp:Label id="lblMName" runat="server" Text="Middile Name" /> </td>
 <td><asp:TextBox ID="tbMName" runat="server"></asp:TextBox></td></tr><tr>
 <td><asp:Label id="lblLName" runat="server" Text="Last Name" /></td><td><asp:TextBox ID="tbLName" runat="server"></asp:TextBox></td></tr><tr>
 <td><asp:Label id="lblAge" runat="server" Text="Age" /></td><td><asp:TextBox ID="tbAge" runat="server"></asp:TextBox></td></tr><tr>
 <td><asp:Label id="lblMailId" runat="server" Text="Email" /></td><td><asp:TextBox ID="tbEMail" runat="server"></asp:TextBox></td></tr><tr>
 <td><asp:Label id="lblSex" runat="server" Text="Sex" /></td><td><asp:TextBox ID="tbSex" runat="server"></asp:TextBox></td></tr><tr>
 <td colspan="2"><input id="btnCallBack" type="button" value="Submit" onclick="InitiateCallBack();"/></td></tr>
</table>

Server side code is as

public partial class Callback : System.Web.UI.Page,ICallbackEventHandler
{
    string result;
    protected void Page_Load(object sender, EventArgs e)
    {
        if (Page.IsCallback)
            return;
        //Creating a reference of Client side Method, that is called after callback on server
        String cbReference = Page.ClientScript.GetCallbackEventReference(this, "arg",
            "ReceiveServerData", "");

        //Putting the reference in the method that will initiate Callback
        String callbackScript = "function CallServer(arg, context) {" +
            cbReference + "; }";

        //Registering the method
        Page.ClientScript.RegisterClientScriptBlock(this.GetType(),
            "CallServer", callbackScript, true);
    }
    public void RaiseCallbackEvent(String eventArgument)
    {
        string firstName = tbFName.Text;
        //Read other data as well

    }
    public string GetCallbackResult()
    {
        return result;
    }
}

And the client side method is

function InitiateCallBack() {
     //Intiate the callback
     CallServer("",'');
}

// Called after the server side processing is done
function ReceiveServerData(arg, context) {
    //arg: hold the result
    //Updating the UI
    document.getElementById('divCallbacl').innerHTML = arg;
}

After filling this form, I submitted it. Now if you try to access the entered using control’s property, you would not get it.

Let’s dig it more and check the form collection, whether the data is passed from Client to server or not

So as you can see that the data is not passed in form collection

But let’s put the following lines of code in java-script, just before initiating the call for Callback as

 function InitiateCallBack() {
	__theFormPostCollection.length = 0;
        __theFormPostData = "";
        WebForm_InitCallback();

        //Intiate the callback
        CallServer("",'');
}

Now let’s run the code and submit the form as earlier.

Now let’s check the form collection.

What a surprise, we got all the input data in form collection. That’s nice.

Now access the data using control’s property.

and you got it.

Now let’s try to see, what does the extra lines of code does

//This Clear the earlier the old data in form collection.
__theFormPostCollection.length = 0;
//It sets the forms data to empty
__theFormPostData = "";
//This method builds the body of the POST request when the page loads. The body of the page is a string 
//(that is __theFormPostData) filled with the contents 
of the view state and all of the input fields in the form.
WebForm_InitCallback();

But I would suggest to use these line at caution. Use only when you need to collect the update from Page during Callback. If you don’t need to get some data or it is in readonly page, don’t use it it introduce extra overhead to your page and costs at performance point of view.

Hope you  all have enjoyed the post.