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abertram
Jan 16, 2009, 9:52 AM
Hey, using Coolite for the first time on a project and it's pretty exciting.

I use UserControls pretty extensively as sort of "pre-configured" Controls (like bundling a Window and it's children in a user control for re-use). But then it's difficult to reference the Ext client objects them from parent controls, especially from a Handler attribute where you can't use <%= Mywindow.ClientID %> idiom.

One thing I've added to the code on my end is an IClientReferenceProvider interface that provides a hook into the TokenUtils.ReplaceIDTokens() method:



public static string ReplaceIDTokens(string script, Control seed)
{
Regex regex = new Regex(TokenUtils.IDPattern);
MatchCollection matches = regex.Matches(script);
Control control = null;
string id = "";
foreach (Match match in matches)
{
id = match.Value.Remove(match.Value.Length - 1).Remove(0, 2);

control = ControlUtils.FindControl(seed, id);

if (control != null)
{
if (control is Observable)
{
script = script.Replace(match.Value, control.ClientID);
} // ADDED
else if (control is IClientReferenceProvider)
{
script = script.Replace(match.Value, ((IClientReferenceProvider)control).GetClientRefer ence());
} // END ADDED
else
{
script = script.Replace(match.Value, string.Concat("Ext.get(\"", control.ClientID, "\")"));
}
}
else
{
script = script.Replace(match.Value, string.Concat("Ext.get(\"", match.Value.Remove(match.Value.Length - 1).Remove(0, 2), "\")"));
}
}

return script;
}

and then, UserControls implementing IClientReferenceProvider can either return the ID of the main container control or even return a reference to a custom object that provides a client interface to parent objects like:

MyUserControl.ascx


<script type="text/javascript">
<%= ClientID %> = {

show: function(activityID) {
<%= Store1.ClientID %>.baseParams.activityID = activityID;
<%= Store1.ClientID %>.load();
<%= Window1.ClientID %>.show();
}
};
</script>

MyUserControl.ascx.cs


public class MyUserControl : UserControl, IClientReferenceProvider
{
public string GetClientReference() {
return ClientID;
}
}

It's not 100% elegent but it's proved useful in UserControls that build heavily on existing controls with minimal additional logic. What do you think? Maybe I'm altogether missing a better way of doing this...?

geoffrey.mcgill
Jan 21, 2009, 7:15 PM
Hi abertram,

Thanks for the feedback!

One control we're been experimenting with for a while now is the <ext:TokenScript>, which enables you to add script tokens to be parsed from inside a standard <script> block.

Example


<ext:TokenScript runat="server">
<script type="text/javascript">
var doSomething = function () {
#{TextField1}.setValue('Hello World!');
}
</script>
</ext:TokenScript>

The above token (#{TextField1}) is basically the same as writting <%= TextField1.ClientID %>

You might find this helpful, although I'm not 100% sure it was included with the v0.7 release or whether it will be included in a future release. We also renamed from <ext:TokensScript> to <ext:TokenScript>.

As mentioned above, we're still experimenting with this control, but any feedback you can provide would be helpful.