CODEWITHSUNDEEP
c#asp.netjavascriptmaster-pages
Rob Cooper
Rob Cooper

Reputation: 28867

Element-enhancing JavaScript in ASP.NET Master Pages

I have some JavaScript (created by a third party) that does some whizzbang stuff to page elements to make them look pretty. The code works great on single pages (i.e. no master), however, when I try and apply the effects to a content page within a master, it does not work.

In short I have a master page which contains the main script reference. All pages will use the script, but the parameters passed to it will differ for the content pages.

Master Page Script Reference

<script src="scripts.js" language="javascript" type="text/javascript" />

Single Page

<script>
    MakePretty("elementID");
</script>

As you can see, I need the reference in each page (hence it being in the master) but the actual elements I want to "MakePretty" will change dependant on content.

Content Pages

Now, due to the content page not having a <head> element, I have been using the following code to add it to the master pages <head> element:

HtmlGenericControl ctl = new HtmlGenericControl("script");
ctl.Attributes.Add("language", "javascript");
ctl.InnerHtml = @"MakePretty(""elementID"")";
Master.Page.Header.Controls.Add(ctl);

Now, this fails to work. However, if I replace with something simple like alert("HI!"), all works fine. So the code is being added OK, it just doesn't seem to always execute depending on what it is doing..

Now, having done some digging, I have learned that the content page's Load event is raised before the master pages, which may be having an effect, however, I thought the JavaScript on the page was all loaded/run at once?

Forgive me if this is a stupid question, but I am still relatively new to using JavaScript, especially in the master pages scenario.

How can I get content pages to call JavaScript code which is referenced in the Master page?

NOTES:

Upvotes: 3

Views: 3987

Answers (5)

Mario
Mario

Reputation: 3445

When using master pages, you need to be careful with the html attribute ID, since .NET will modify this value as it needs to keep ids unique.

I would assume your javascript is applying css styles via ID, and when you are using master pages the ID is different than what is in your aspx. If you verify your javascript is always being added, your answer needs to take into account the following:

  • ALWAYS set your master page id in page load (this.ID = "myPrefix";)
  • Any HTML element in your master page will be prefixed by the master page id (i.e.: on the rendered page will be "myPrefix_myDiv")
  • Any HTML element in your content place holder id will be prefixed with an additional prefix (i.e. myPrefix_ContentPlaceHolderId1_myDiv)

Please let me know if I can clarify anything. Hope this helps!

Upvotes: 0

Aaron Powell
Aaron Powell

Reputation: 25097

Why not use jQuery to find all the controls? Something like this:

$(document).ready(function(){
  $("input[type='text'], input[type='radio'], input[type='checkbox'], select, textarea").each(function(){
    MakePretty(this);
  });
});

This way you'll get all elements on the page, you can wait until the page is ready (so you don't modify the DOM illigally). The jQuery selector can get the elements in a bit more of a specific format if you need (ie, add a root element, like the ID of the body div).

It'd also be best to modify the MakePretty method so it takes the element not the ID as the parameter to reduce processing overhead.

Upvotes: 1

Lou Franco
Lou Franco

Reputation: 89192

Once you use Master Pages, the ids of controls on the client side aren't what you think they are. You should use Control.ClientID when you generate the script.

Upvotes: 0

John Sheehan
John Sheehan

Reputation: 78124

Put a ContentPlaceHolder in the head section of the master page, then add a asp:Content control on the content page referring to the placeholder and put your script in that control. You can customize it for each page this way.

Also, the reference by ID may not be working because when you use Master Pages, the control IDs on the page are automatically created based on the container structure. So instead of "elementID" as expected, it may be outputting "ctl00_MainContentPlaceHolder_elementID" View your source or use firebug to inspect your form elements to see what the IDs outputted are.

Upvotes: 5

roenving
roenving

Reputation: 2636

Isn't it possible to do with clean javascript ?-)

-- just add something similar to this inside the body-tag:

<script type="text/javascript">
  window.onload = function(){
    MakePretty("elementID");
  }
</script>

By the way the script-tag has to have an end-tag:

<script type="text/javascript" src="myScript.js"></script>

Upvotes: 2

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