Shortly before I headed out to the airport last Wednesday, I received the fateful email from my customer notifying us that they have decided to abandon using the variations feature in Microsoft Office SharePoint Server (MOSS) 2007. Note that the original release date for our solution was October 19th -- and the decision to cut variations from our solution would obviously require significant rework (meaning we would not come close to hitting our original date). This was obviously a difficult decision and required careful consideration to determine how best to move forward.
I'll cover the reasons why this decision was made over a series of three posts -- with each post detailing each of the major issues that we faced while trying to use variations.
In part 1, I'll focus on the incompatibility of the out-of-the-box (OOTB) variations feature and the OOTB content types feature.
We first encountered this problem about four weeks ago when we noticed that pages were not always propagating from the source site (i.e. label ) to other variation sites. Based on a cursory scan of the variation logs, the failures appeared to fall into one of the following error categories:
- The variation system failed to pair up pages http://foobar/en-US/Support/FAQs/foo/Pages/default.aspx and /ja-JP/Support/FAQs/foo/Pages/default.aspx because their Content Types do not match.
- Object reference not set to an instance of an object.
The first error is due to the fact that MOSS 2007 does not automatically change the content type of the variation page to match the source page and instead simply throws an error. As the error message clearly states, the pages are not "paired up" (which I infer to mean that there is no corresponding entry in the hidden Relationships List) and therefore no updates are propagated to the variation site (e.g. "ja-JP") when changes are made to a page on the source site (in our case, "en-US"). [Make note of the hidden Relationships List -- it becomes important in part 2 of this series.]
To be honest, we "punted" the errors in the second category above (i.e. those caused by some mysterious NullReferenceException), since there weren't very many and we had more important problems to investigate. Besides, we could always come back to that later if we found it still occurred in subsequent builds of our solution.
The fundamental problem is that we change the content type (and page layout) of the default pages in order to display the hierarchy of Frequently Asked Questions (FAQs) next to a list of the FAQs for the currently selected site within the hierarchy. This is cleverly done using a custom page layout that one of my fellow MCS team members, Ron Tielke, developed that contains an ASP.NET menu control on the left and a Content Query Web Part on the right. In other words, the content type of default.aspx starts out as Welcome Page (since we are using the OOTB Publishing with Workflow site definition), but we change it to FAQ Node Page (a custom content type that we have defined which derives from Page -- just like Welcome Page). Consequently, users can drill down into the FAQ sites and view FAQs within a particular category.
Once we understood the nature of the error, we believed that we could circumvent the problem with custom content types by waiting until after the variation sites and pages are propagated (and "paired up") before changing the content type. In fact, this worked…for a while.
Note that we are migrating this customer from a legacy system and we have developed custom content migration tools to build out the site structure in SharePoint and bulk load about 3,200 FAQs into the MOSS-based solution.
To avoid the "Content Types do not match" problem, we modified our content migration tool to break it down into a series of steps (which were previously performed in a "fast-as-you-can" fashion). The “pace” of the migration would then need to controlled by the user performing the migration:
- Run the first step to create the FAQ sites with the default page having the default content type (i.e. Welcome Page)
- Wait for steady state (i.e. let the SharePoint timer job finish creating variation sites and “pairing” up the pages)
- Run the next step of the migration to change the default page of each and every FAQ site to use the custom FAQ Node Page content type
Last week, I had a conversation with the Program Manager who spec'ed the Variations feature and he was quick to trump what I consider to be a SharePoint bug with the "by design" card. He cited the fact that there are many things not handled by the variations feature, such as lists, document libraries, etc.
I am fine with those limitations (in part because I had read about them months ago when researching the variations feature so I knew to set some expectations with the customer on what variations will and will not do). Acknowledging that MOSS 2007 variations is all about Web Content Management (WCM), it is perfectly reasonable that the propagation only include the Pages library (or the Paginas library, as we discovered during our testing of the SharePoint language packs -- but that's a funny story that deserves a post of its own, some other time perhaps).
As I mentioned earlier, our workaround (i.e. modifying our content migration tools) worked for a while, however we discovered just how "brittle" our solution was when we attempted to create a new variation label. Yep, you guessed it...lots of errors about "failed to pair up pages ... and ... because their Content Types do not match."
We even contemplated creating all of the possible variation labels this customer would need for the foreseeable future, but at some point, the insanity had to stop (you'll hear more about the other problems we encountered in parts 2 and 3). Hence the decision to stop using the variations feature altogether.
The fundamental problem that I have with the "by design" response is that if you can break one feature in a product by using another feature in the product, it is either "poor design" or "poor implementation." In defense of the SharePoint team, I believe it is the latter and I believe it was simply due to time constraints in the original schedule (the PM indicated they discovered this problem around the Beta 2 timeframe). I certainly hope they have every intention of fixing this (although it is too late for my current customer) but based on my conversation with the PM, I don't see this happening anytime soon (it is certainly not slated for SP1).
[Update (2007-11-28): According to a follow-up by Stefan Goßner, it appears this will be fixed in a QFE by enabling content types on the Pages library in destination labels. Excellent!]
Here are the repro steps to break the variations feature using no custom code and no custom content types:
- Create a new Web application
- Create a site collection using the Publishing Portal site definition
- Configure variations using / as the Location for the Variation Home (use defaults for all other settings)
- Create a new variation label with the following:
Label Name: en-US
Display Name: English (United States)
Locale: English (United States)
Source Variation: Yes
Publishing site template: Publishing Site with Workflow
- Create the variation hierarchies (to create the /en-US site)
- Create a new site under the variation source site (/en-US/foo)
- Change the content type of the default page in the new site (/en-US/foo/default.aspx) from Welcome Page to Article Page. Note that in order to change the content type of the page, you need to view the underlying Pages library (use Site Actions --> View All Site Content) and then edit the properties on the page.
- Change the page layout to Article page with summary links and approve the page.
- Create a new variation label with the following:
Label Name: ja-JP
Display Name: Japanese
- Create the variation hierarchies (to create the /ja-JP and /ja-JP/foo sites)
- View the variation logs and notice the failure with the following error:
The variation system failed to pair up pages http://foobar/en-US/foo/Pages/default.aspx and /ja-JP/foo/Pages/default.aspx because their Content Types do not match.
[Part 2 in this series is now available.]