To finish a set of posts about the fun I’ve had in deploying document sets as XML content types, here’s a fun little bug vagary I encountered. In the video walkthrough, there’s a section on deploying the custom WelcomePage to your site, and provisioning some WebParts automatically to that page.
You achieve this in the Elements.xml file of your WelcomePage module by including some <AllUsersWebPart>> sections. Within those tags, you enter the definition of the webpart, and you can reuse the built-in webparts.
(Hint: to get at the required definition for built-in SP webparts, find the webpart in the Webparts Gallery in Site Settings, save a copy of the file to your hard drive (as a .dwp file) and then open that file in Visual Studio. You get the required info. Neat.)
You can then deploy your feature, and assuming you’ve covered all the bases your Document Sets, with custom Welcome Page should be deployed. But here’s a problem. Let’s say you make some changes to it, and redeploy the feature. You may experience one of a series of behaviours:
1) None of your changes are displayed
2) Your changes are displayed OK
3) You end up with multiple webparts on your custom Welcome Page.
It’s the third issue I tripped over, and it seems to occur if/when you manually deactivate and reactivate your feature (using the “deploy” feature from VS doesn’t seem to cause this.) It makes some sense – the Elements.xml file says “add these webparts to this page”. Assuming you’ve not added any FeatureDeactivating event receiver to remove the webparts when the feature is deactivated, well, you’ll end up with lots of webparts on the one page.
This being the case, how do you actually go about getting rid of the extra webparts on the page? Retracting the solution doesn’t help. You could completely bin your site content type, site or even site collection. That would probably do it. But it’s a bit drastic. The alternative? Update the database manually. You can decide if this is more drastic than the previous options.
To be clear, you should never, ever, on any account, ever, manually hack the SharePoint content database!
But if you want to do it, here’s how: