Upgrading DNN 3.1 to 3.2.2

Michael Flanakin — Tue, 07 Feb 2006 11:30:00 GMT

Mainly for my own benefit, I've accomplished a diff between DNN 3.1 and 3.2.2. View my blog post for details.

First (and Second) Webcast

Michael Flanakin — Wed, 18 Jan 2006 14:52:00 GMT

Well, I actually participated in my first webcast yesterday. Brian Scarbeau invited me to join in on his 3rd DotNetNuke webcast on custom module development to help by answer questions and filling in as needed. It went quite well and I plan on also participating in his 5th webcast on skinning. Should be interesting! If you're interested in DNN skinning, I suggest you check it out.

DotNetNuke Image Module Project

Michael Flanakin — Thu, 05 Jan 2006 13:58:00 GMT

Well, I've been very busy over the past few months. Project after project at home and work. Well, I definitely made sure to get my all-important playtime at home, too, of course. I guess it's all a good thing, tho. I just haven't had too much time for new posts. I do have news, tho. I was just added to the DNN Image Module Project last week. I just got the latest code and plan on adding some of my own updates to it within the next week or so. I look forward to contributing. There aren't too many items in the issue tracker, but I have seen some in the project forums. I'll try to start getting issues in and being productive soon. It should be fun.

DNN and the Lovely "Multiple controls with the same ID" Error

Michael Flanakin — Fri, 25 Nov 2005 15:58:00 GMT

After having this problem several times and continually forgetting the fix, I figured I'd go ahead and make a post about it. Hopefully, it'll save someone time in the future. Let me know if you have a different fix.

Symptoms

When you browse to a DNN page after adding a new module to the page, you receive an error message that is similar to the following:

Multiple controls with the same ID 'ctr123_DD' were found. FindControl requires that controls have unique IDs.

Cause

DNN dynamically loads modules to the page when it loads and references them using the Control.FindControl() method. As the error specifies, FindControl() can only be used when all IDs are unique. This usually happens when a module definition has been recently modified. DNN modules are identified using a combination of the key and type properties. To specify the control that should be loaded when a user browses to a page with the module, the key should be blank and the type should be "View". The default edit control (i.e. Add content) and the settings controls should have key values of "Edit" and "Settings", respectively. All other controls need to have unique key values. When non-unique key values are used, DNN loads all of the controls with the same ID, which is the true culprit.

Resolution

First, you'll have to know what module is causing the problem. If you are unsure of which module is causing the problem, there are three ways to figure it out:

If a module was just added to the page before the error occurred, the module that was added is most likely the problem. (Cause you needed me to tell you that, right?)
If a module on the page that's giving you the error was just added, that module is most likely causing the error. (Another great hint!)
If neither of the previous identification methods work, the module ID is listed in the error. "ctr123_DD" refers to module 123. Take a look in the dnn_Modules table and the row with that ModuleId is definitely the problem.

After finding the offending module, browse to the module definitions page (Host > Module Definitions) and check to ensure all module controls have unique key values. Remember: default view is blank, default edit is "Edit", settings is "Settings", and all others can be whatever makes your little heart go pitter-patter. Once the key values are corrected, you will most likely have to restart IIS. The quickest way to do this is to use iisreset (Start > Run, type iisreset, click OK).

More Information

Applies to: DotNetNuke 1.0 - 3.1 (I don't think it's been fixed in newer releases, yet; but I haven't confirmed anything newer than 3.1)
There is another error that does not specify the module ID, "Multiple controls with the same ID 'ctr' were found." This fix does not apply to those. If/when I run into that one again, I'll try to post a fix on that, too.
I may have found the cause of the 'ctr' error. It seems that this is caused with malformed HTML within the ASCX and/or mis-matched assembly (I didn't notice there was a build error because VS was saying it built successfully, for some reason.) This happened right after editing a module control, so I just opened the ASCX file in the designer and solved the problem pretty easily. I'm pretty sure this also happened when I wasn't customizing a control, but I can't really remember. That's all I really have right now. Hope it helps someone.