Attach Client Side Event to Ajax HtmlEditorExtender

Introduction

This is an awesome trick which will guide you to add any client side events to a Ajax HtmlEditorExtender.

Background

While coming across one question on CodeProject, I tried to implement this and finally succeeded. Let me explain this to you all.

Using the Code

To add an AJAX HtmlEditorExtender, you need to add the following code in aspx page. Mark the TargetControlID="txtEditor" in HtmlEditorExtender.

<asp:TextBox ID="txtEditor" 
             runat="server" 
             TextMode="MultiLine" 
             Height="600px" 
             Width="600px">
</asp:TextBox>
 
<asp:HtmlEditorExtender ID="htmlEditExtForTextBox" 
                        TargetControlID="txtEditor" 
                        runat="server">
</asp:HtmlEditorExtender> 

Now let's analyze the HTML rendered in browser for this.

For TextBox txtEditor

The TextBox txtEditor is now hidden as we can see below display: none; and visibility: hidden are added to the Style Attribute of TextBox.

<textarea style="height: 600px; width: 600px; display: none; 
visibility: hidden;" id="txtEditor" cols="20" rows="2" name="TextBox1"></textarea> 

For AJAX HtmlEditorExtender

There are many divs generated to facilitate the HTML Editor. But to achieve our task, let's just pull out the main div (with the help of FireBug Inspect Element Feature in FireFox) inside which we enter the text.

<div id="txtEditor$HtmlEditorExtenderBehavior_ExtenderContentEditable" style="height: 80%; overflow: auto; clear: both;" class="ajax__html_editor_extender_texteditor">
</div>  

So, What's Next ?

Now, it is just a matter of attaching any Client Side Event to this rendered div described above. Let's try to attach KeyUp Event.

To do that, we have to place the below script inside Body tags. Putting this in Head tag will not work, as the HtmlEditorExtender is not loaded at that time.

<script type="text/javascript">
    Sys.Application.add_load(function () {
        // Get the Editor Div by Class Name. 
        var htmlEditorBox = $('.ajax__html_editor_extender_texteditor');
        
        // Attach the keyup Client Side Event to the above div.
        htmlEditorBox.keyup(function () {
            alert(this.textContent);
        });
    });
</script> 

The code is quite self explanatory. It gets that main Editor div by its class name. Then alerts its Text Content.

Points of Interest

• As we attach keyUp Event, we can attach any Event with the HtmlEditorExtender.
• Please don't forget to include the jQuery file inside head tags as we are using jQuery while attaching the Event. You can also directly include the below script to include the latest jQuery file.
  HTML

  <script src="http://code.jquery.com/jquery-latest.min.js" type="text/javascript"></script>  

History

• 30 December 2013 - First version submitted for approval