Selecting by ID attribute using JQuery in ASP.NET

Question

I've just started using JQuery in VS 2008, and so far I like it! But, I'm confused about how I should be using JQuery in order to select asp.net controls on a webpage.

For example, I have the following code (just a mock-up):

<asp:textbox id="txtSomeData1" runat="server" text="Some Data!!"></textbox>

Now, if I want to use JQuery to select the textbox and change it's text to "Some More Data!!", then I would have to do something like:

$('input#ctl00_ContentPlaceHolder1_txtSomeData1').val('Some More Data!!');

Which, quite frankly, is annoying because I don't want to mess with having to figure out what the id of the control is after it's rendered to the webpage (ctl00_ContextPlaceHolder... blah blah blah).

Is there a way that I can select the textbox without having to use the id of it? Also, I know that you can select by class name, but that doesn't help much if the control that you're selecting doesn't have a class.

Am I just missing something here?

JUST TO REITERATE: I do not want to use a class to select the input tag!! I would like to use the id "txtSomeData1" and not the long id that is rendered to the webpage.

Answer 1

There are lots of selectors to use... maybe adding a class is what you want to do.

http://docs.jquery.com/Selectors

Answer 2

jQuery Wildcard Selectors are what you may be missing here.

Answer 3

$('input').find('#ctl00_ContentPlaceHolder1_txtSomeData1').val('Some More Data!!');

Answer 4

What you want to do is either:

$("input[id$='_txtSomeData1']").val().....

or you could add a class or custom attribute to the textbox that you can select on

Answer 5

This is a big complaint the community has with ASP.Net web forms. In ASP.Net 4.0 you get control of your IDs back so it's like you're wrote it in raw HTML. Alternatively, without .Net 4.0, you could use ASP.Net MVC which, for the most part, doesn't use server controls, so you wouldn't have the issue.

But like happytime harry says, adding a class may be want you want if you're working with web forms and jquery.

Answer 6

You can add 'marker' classes to any control whose sole purpose is for use in a jQuery selector. That, along with navigating the tree heirarchy (something like "$(element).children('.myClass').show()" might be a good way to do this without IDs.

Btw, http://visualjquery.com/ is a great way to view the jQuery APIs etc.

Answer 7

You can use the element[id$=Identifier] notation, which looks for the id ending with the text you specify (it's the ID you specify in ASPX markup). Here is an example illustrating how you can use it (see slide #30): Building intranet applications with ASP.NET AJAX and jQuery.

Answer 8

if the javascript is on the same .aspx file, you can do:

$('<%= txtSomeData1.ClientID %>').val('Some More Data!!');

Answer 9

If you are going to externalise the JavaScript to its own .js file you are stuck with either hard coding in the id (most efficient), some regular expression selector or using the inefficient by class name selector.

However if it is in the same file as the .NET control you could always use $('<%=txtSomeData1.ClientID %>')