Hi Jon

I've implemented the HelloAJAX into a module, but I'm having difficulties seeing how it works ...

I get an error:

"400 - unable to cast object of type System.Web.UI.HtmlControls.HtmlTitle' to type 'DotNetNuke.UI.Utilities.IClientAPICallbackEventHandler"

My ASCX control with HelloAJAX is loaded into a placeholder in another ASCX that is loaded by another ASCX that is loaded by a module(! yes I know thats not great), so I guess that it is having problems finding the correct parent control...

The code I used (HelloAJAX converted to C#) is:

public class Foo : Bar, IClientAPICallbackEventHandler  // class Bar inherits from PortalModuleBase

protected TextBox txtAjax;
protected Button btnAjax;
protected CheckBox chkAjax;
protected Label lblAjax;

private void Page_Load(object sender, System.EventArgs e)
{
           this.btnAjax.Attributes.Add("onclick", ClientAPI.GetCallbackEventReference(this, "dnn.dom.getById('" + this.txtAjax.ClientID + "').value", "successFunc", "'" + this.ClientID + "'", "errorFunc"));
            this.chkAjax.Attributes.Add("onclick", "toggleCont('" + this.ClientID + "')");

            if (!this.Page.ClientScript.IsClientScriptBlockRegistered("helloajax.js"))
            {
                this.Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "helloajax.js", "<script language=javascript src='" + this.ModulePath + "helloajax.js'></script>");
            }
  // ... etc
}

public string RaiseClientAPICallbackEvent(string eventArgument)
{
            return "Hello AJAX!" + "\r\n" + eventArgument + "\r\n" + DateTime.Now.ToString();
}

Does the parent module have to implement IClientAPICallbackEventHandler as well or is it sufficient to have the ASCX implement it?

In the case of an ASCX that is embedded several layers deep, does each of it's parent ASCX controls also have to implement IClientAPICallbackEventHandler?

In HelloAJAX, Blue.ascx.vb the comment reads "'two levels up, since immediate parent is the placeholder" -- what exactly is the required control to use in ClientAPI.GetCallbackEventReference()?  The module's top level control, or the ... ? (in my case I have a placeholder in a placeholder in a placeholder, all of which use LoadControl)

I think ClientAPI looks good and will really make these modules great :) .. once I figure out how to use it! :)

Thanks!

JK

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To understand the sample better, please refer to this blog. 

The first question is, are you dynamically loading modules.  If not, then the code in that blog, and therefore sample is not really what you are after.  In other words, if the control that you are needing is already present for the page's init event, you should just be able to reference it directly.   You are using this.parent.parent.parent.parent...   why not just reference it by its actual name?  Again, if you are dynamically loading the contols, you cannot directly reference.  Instead you need to reference a control to handle the request that is present during init.

I also want to note that a new enhancement that I am in the process of making as part of the DNNTabStrip should completely simplify a lot of this.

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That makes sense.  Would you mind sending me a simple installable example of your use-case?  I want to verify that my new enhancement to the ClientAPI callbacks will be benificial to it. 

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