Hi again,

Thanks for the example file. However, the WebTab has AutoPostBackFlags set to on, as opposed to Async. Setting it to Async stops it from working. I suspect this is because the updatepanel requires a proper post back to be triggered?

This is why we used JS in our scenario, to trigger an Async postback on the client event SelectedIndexChanged, but this is the point where we run into errors. Looking online suggests we might have incorrexy AJAX assemblies, but all looks in place from what I can see

To help further, we have the following update panel:

<asp:UpdatePanel ID="updatepanel1" runat="server">
<ContentTemplate>
<div id="AsAtCtlContainer">
<jims:AsAt runat="server" ID="AsAtCtl" ExportClientClick = "exportClick();"/><br /><br />
</div>
<button onclick="BLOCKED SCRIPT__doPostBack('masterContentBody_updatepanel1', '');" runat="server" id="button1"></button>
</ContentTemplate>
</asp:UpdatePanel>

The 'AsAtCtl' contains a webdropdown that we access through a property to change it. By manually clicking the button, everything works as we want, only the updatepanel is updated, and the date is changed correctly.

However, if we have ClientEvents-SelectedIndexChanged="doPostBack" in the WebTab, and the following BLOCKED SCRIPT

<script type="text/javascript">
function doPostBack()
{
document.getElementById("<%:button1.ClientID%>").click();
}
</script>

We get the error. This seems to only happen when EnableLoadOnDemand is set to true as well. 

Hope that helps!

Just in case anyone else is struggling with a similar issue, it appears to be a problem with WHEN you call the javascript function. Moving it from the client side SelectedIndexLoaded to client side AJAXResponse runs it properly (albeit slowly). Just testing now to see what the best client side event is to trigger the function

Hello Alex,

Thank you for getting back to me.

I set the AutoPostBackFlags to Async, Afterwards I am handling client side ActiveTabChange event. In this event I am triggering a click for the button and everything works as expected, a click is triggered, respectively a postback is fired and selected index of the WebdropDown is changed. Please keep in mind that the EnabledActivation property or WebTab should be set to true in order to fire this event. For example:

function WebTab1_ActiveTabChange(sender, eventArgs)
{
 document.getElementById("Button2").click();

}

I modified my sample and I am attaching it for your reference.

Please let me know if you have any additional questions regarding this matter.

Thanks again for your continued support!

From the looks of it though, that button still causes a full postback? I need the WebDropDown to be updated WITHOUT full postback, and I need it updated after a partial postback from the WebTab. Also note that we have the EnableLoadOnDemand set to true, which seems to cause issues with this. 

I'll double check the sample with out project, but from what I can see, it's still doing a full postback

EDIT: this is also being done within an ASP:content page, which inherits from a Master page. Does that change the setup? Still getting a null reference javascript error after implementing your solution into our project

ANOTHER EDIT: seems having AJAX enabled for the WebTab is causing issues also

Main problem is that we need to have AJAX enabled, otherwise the WebDataGridView loses it's content after loading another tab. The problem with having the client side selectedindexchanged is that it seems to do the postback before the server side, which results in no data being loaded. Is there any way to say in the javascript, "Wait until the server side SelectedIndexChanged event has finished doing it's processing, THEN do some stuff"?

Hi again,

Thanks for the example file. 

I am glad that you've managed to resolve this issue.

Thank you for using our controls.

Ended up having a fiddle around and got it to work how I wanted (looks like it was a combination of incorrect properties and controls, but what they were I'm not too sure!). The posts here regarding updating a webdropdown from a webtab helped immensely however!

Just to add further to this, I've noticed that the WebDataGrid is always null when I'm debugging. For instance, in the Page_Load event, the WebDataGrid is null.

EDIT: Looks like the WebDataGrid only loads if it is in the initial selected tab. Any other tabs with a webdatagrid that aren't selected on start up don't seem to get instantiated (using the above WebTab properties). Is the proper behaviour? If it is, is there a way I can force them to be loaded so that I can keep in place the WebTab options we have?