I am blogging this as I hope to prevent anyone else spending extra time on this. I was having problems with a content type/site columns feature. Actually everything was working correctly except choice fields were not displaying:
I should have been guided by the fact that I could do it in a Console application but not in a feature! However, I am getting a little older and my mind is still “Tarp as a Shack” you get it! The problem is that in Sandboxed solutions intellisense is not pared to the subset of code that is allowed! I think this particular code issue is a bug and needs to be addressed by Microsoft as it has a far-reaching effect of having code that should be Sandboxed run as a farm solution. In any event here is how I troubleshot this particular issue:
Lookup Field working
Choice Fields not working
Multi Choice Field is disabled???
Debugging when these are added shows that the field is not being updated:
Shows count = 0 on choices????? Hmmm; this can only mean one thing! We cannot change the choices in a sandboxed solution!
Yes, This is a bug!!!
I added the code as a farm solution and these columns work!!!
Okay! Why am I blogging this? To do sandboxed code without a full trust proxy there are many decisions that are made to make your code work! For example in this project one of the decisions I made was that I didn’t have access to the site property bag from a sandboxed solution so I had to resort to adding a new list for Configuration as Microsoft’s new guidance around content types is not to delete them but hide them as they may be referenced from other sources. So, I added the list and used it to see if the content type exists, if it does: Hide the content type and add a new one with a different name on the feature activation event. Then write the new name back to the configuration list. Another, was I couldn’t use logging . Event logging is not allowed in a sandboxed solution.
To further address this is that Microsoft has published SharePoint 2010 Guidance solution which does have a logging and Property bag ( PROXY) which mitigates these two issues. So maybe they should be on every SharePoint 2010 farm. I have spent an inordinate amount of time trying to solve issues around adding content types in code from within a sandboxed solution . From what I see here is that it is possible for a subset of the fields that might be required but certainly not Choice fields. So the end result is that I could have made this a farm solution to begin with. The solution has three projects content type (Farm Solution) drop down lookup lists (Sandbox Solution) and configuration list (Sandbox Solution). I hope this helps others not make my mistake in the future.