Weblog of Nirandas

I been using prototype for few of my project lately, however, I been hearing some wonderful things about jquery so decided that it is the right time to give it a short. Here is what I tried to implement with jquery on asp.net mvc. I decided to add the ability to automatically check whether the username given by the user on the registration page is already taken or is available. For this I added a new action on the account controller named “check”. This action returns a ContentResult containing the text to display. Code follows:

public ContentResult Check(string id)
{
if (Provider.GetUser(id, false) == null )
return Content(”");

return Content(”The username is already taken.”);
}

this function takes the username entered by the user as its parameter and checks if the username is available or not. If available, it returns nothing and if the name is already taken it returns the error message. After getting this done, now we will have a look at the changes made to the registration page’s view.

The main change other than adding the jquery magic, is to add a span where to display the output from our check action. We will place it just after the text field for entering username. Modified table row of the username field is shown below.

<tr>
<td>Username:</td>
<td><%= Html.TextBox(”username”) %>
<span id=”isUsernameAvailableResult”></span>
</td>
</tr>

after this, we will add the following script to the view. Note: I have included the jquery.js in this snippet, in real world you would probably have it included inside your master page.

<script src=”/content/js/jquery-min.js” type=”text/javascript”></script>
<script language=”javascript” type=”text/javascript”>
$(document).ready(function(){
$(”#username”).blur(function(){
$(”#isUsernameAvailableResult”).load( “check/” + escape(document.getElementById(”username”).value) + “.aspx”);
});
});
</script>

Here we first add the anonymous function containing the actual code which does the ajax call to the blur event of the username text box. We do this inside the jquery special document.ready event)

The code just selects the span to contain the result and load the output of the ajax call into it. Here
the request url is “/account/check/[user entered name here].aspx”. Note: I use a modified routing rule in which the url always ends in “.aspx”. This is to make it work it on iis 6 also without any big changes.

jquery is a great tool to have, and with the introduction of asp.net mvc, integrating jquery with asp.net is easyer than ever. Enjoy,

I been interested in asp.net mvc since its preview2 release but really its now that I am playing with it. I have downloaded the asp.net mvc preview4 and is currently enjoying the cool new method of developing asp.net websites.

An important feature of asp.net mvc framework is its pretty urls and ability to map incomming requests to controllers and action like other mvc frameworks. However the url format like “/blog/archive/hellow-world” would not work on iis6 by default. For these types of urls to work on iis, we either have to setup iis to route all incomming requests to asp.net or use a different url format.

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