CascadingDropDown placed inside an asp:EditItemTemplate.

I tried the cascading dropdownlist when the user clicks on edit on a formview, but I realized from the following error that this will not work:

System.InvalidOperationException: The UpdatePanel 'EditUpdatePanel' was not present when the page's InitComplete event was raised. This is usually caused when an UpdatePanel is placed inside a template.

I also found a previous threadhttp://forums.asp.net/thread/1255759.aspxwhere the respondent confirmed that the updatePanel must be outside of the GridView

Does that mean that theAtlasControlToolkit:cascadingdropdown control cannot be used within any databound templated controls (such as GridView, FormView, Details, etc.)?

I don't believe so. UpdatePanel has "special needs" on the page which is why it probably has this issue. I haven't tried this but I think CascadingDropdownshould work OK - I can't think of why it wouldn't. Can you give it a try and report back?

I think the problem is that theatlasToolkit:CascadingDropDown requires anatlas:UpdatePanel around the dropdownlists otherwise changing the selection in one dropdownlist would not affect the next. But sinceatlas:UpdatePanel cannot be placed within the EditItemTemplate therefore it seems that there is no way to put theatlasToolkit:CascadingDropDown within the EditItemTemplate.

Here I tried 3 scenarios in addition to the one I described in my previous post:

1- The cascadingdropdown lists work if placed within atlas:UpdatePanel outside of an EditItemTemplate:http://www.webswapp.com/codesamples/aspnet20/atlas/cascadingdropdown.aspx

2- The cascadingdropdown lists not working if placed within the EditItemTemplate and the atlas:UpdatePanel outside the FormView. http://www.webswapp.com/codesamples/aspnet20/atlas/cascadingdropdown2.aspx

(On my local PC, a JavaScript popup dialog box comes with the following error: "System.ArgumentException: Invalid postback or callback argument. Event validation is enabled using in configuration or in a page." But when run remotely you do not get that error. The lists just do not display anything)

3- The cascadingdropdown lists not working if placed within the EditItemTemplate and no atlas:UpdatePanel on the page

The source code for all scenario are listed on the demo pages.

CascadingDropDown does not need an UpdatePanel to work - the client-side changes are done in script and the web service requests are async thanks to Atlas. So #3 above is the scerario you probably want. I suspect it's not working for you because your ParentControlID properties are pointing at "CascadingDropDownX", but your DropDown controls are named "ddlYYY". Please try fixing that and let us know how it goes!

Hi David,

Thanks for your help. Your suspicion was right. I had the wrong values for the ParentControlID. Now that I corrected them and got it working within the FormView's EditItemTemplate and the data is being updated upon postback successfuly as shown here: http://www.webswapp.com/codesamples/aspnet20/atlas/toolkit_cascadingdropdown.aspx

I am wondering about the possibility of doing 2 more features to make the function of this control equivalent to the server-side controls:

1- How to set the default values upon loading the EditItemTemplate? (Since I could not use the Bind or Eval statements)

2- In order to prevent flashing of the screen when I submit the FormView, I tried using the Atlas:UpdatePanel around the FormView but I got this error message:

Assertion Failed: Unrecognized tag AtlasControlExtender:ValidationScript

That is so cool!

From above...

1) This is a feature we've added to the refresh, which should be available within the next day or so. When it is, you can just add a "SelectedValue='blah'" to the properties and it'll select that value

2) I'm not sure why you're getting that. In any case, in your extender set "SuppressValidationScript='false'" and it'll preven that guy from even loading.

<atlasToolkit:CascadingDropDownID="CascadingDropDown1"runat="server" SuppressValidationScript="false">

I tried # 2 above but I still get the error. The code is exactly as listed in the link I provided before plus the updatePanel surrounding the FormView

<atlas:UpdatePanelID="UpdatePanel1"runat="server">

<ContentTemplate>

<asp:FormViewID="FormView1"runat="server" .... >

</asp:FormView>

</ContentTemplate>

</atlas:UpdatePanel>

SuppressValidationScript="true"

Ok. The first error (above) does not show up but the next errors (which used to appear after I clicked on cancel) is still repeated for each dropdown list: "Assertion Failed: Unrecognized tag atlasControlToolkit:cascadingDropDownBehavior"

That's often related to the relative position of the controls, the extender, and the UpdatePanel. Some wiggling around of the different items can sometimes solve the problem. If it doesn't - and if the new Toolkit release doesn't help - please let us know.