Sakari's SharePoint mumblings

Workflow starts and immediately gives “Error Occurred”

sakarih — Mon, 17 Oct 2011 07:49:53 +0000

Yet one small thing to remember and I hope that someone else will find this posting useful. Consider following scenario: SharePoint Workflow (Visual Studio Worklow -style) runs fine on development environment. From development the workflow is brought to testing (or production if not the happy world) by using wsp’s or other methods.

In testing the workflow immediately gives message “Error Occurred” and in SharePoint logs following line is found with category of Workflow Infrastructure: “Object reference not set to an instance of an object”. In this case I found that this error message is given as the Content Type that workflow uses is not found on Task List. Usually this one goes well when doing a new deployment but if you have deployed earlier and update your workflow with changes to content type then this is possible error.

Usually “Object reference not set to an instance of an object” means that something is missing. It can be missing column from the list or in this case missing content type. This is relatively easy to fix (associate a content type to tasklist or as update procedure delete existing tasklist and create new one from workflow association screen).

Using External Content type or list controls in custom webpart

sakarih — Fri, 12 Aug 2011 04:12:04 +0000

Okay some time has passed after last post but now I have something pretty interesting in my mind. Lately I have been digging SharePoint 2010′s External List and External Content types (Business Connectivity Services, BCS). I need to make my own webpart (Visual Web Part or the regular one) that makes use of the picker that Microsoft uses when you set up your list with either directly External Content type or through lookup field to External List.

From the background I knew instantly that this will be tricky one (due to fact that External List Items are not like SPListItem’s and enumerating external list from code requires bits and pieces of extra with user security and so on).

If you look standard SharePoint 2010 edit form page with developer tools (in IE9) you’ll see that in UI there is mention about the SPFieldBusinessData. Now if you try to search with that term you’ll find pretty much nothing and Visual Studio does not help you either. At first I was hoping that yes it is like regular field in SharePoint but no luck.

After digging more I found some intresting posts about setting up ItemPicker with ExtendedData. Through UI this looks exactly same as the normal SharePoint’s External Item Picker but requires quite good amount of work setting up the ExtendedData. Also I found this not so appealing since in List we have done work already by defining External Content Type and some more properties.

So the search continued to next solution. After digging more into this I found quite nice solution at the moment for this problem. From some forum posts I found references to BusinessDataFieldControl (Microsoft.SharePoint.WebControls -namespace). If you just put this control to your page you’ll end up getting error about the null controls. This was not a good sign. However now there are big thanks to IntelliSense: from that control you can find properties like ItemId, ListId and FieldName. After setting those three properties you’ll get the control showing up and it works when picker dialog is opened (that nice “instant search” by giving some values to control is not working just yet). This was exactly the easy solution what I was looking for but however there are some limitations currently present.

Although I am still considering about using ItemPicker or keep still on searching for the perfect solution. With BusinessDataFieldControl you can find the data from external source but you can get only one line back at the time (let’s say that you have given the external column to show Company from external source and when you pick the company from dialog you just get the company and nothing more).

The search continues…

Passed the 70-576: PRO: Designing and Developing Microsoft SharePoint 2010 Applications Test

sakarih — Sun, 03 Apr 2011 08:22:48 +0000

Finally I got the “last part” of my SharePoint 2010 certification path completed and archieved the MCPD: SharePoint 2010 Developer certification. All what I can say is that books from the course 10232A are good materials for the exam.

SharePoint: differences between SPListCollection and SPListItemCollection

sakarih — Tue, 01 Mar 2011 10:52:24 +0000

Okay the topic might not be as accurate as possible but here is something that I bet almost every SharePoint developer has faced, but might now have had any second thoughts. Back in C# language “principles”, it is not possible to modify collection (List<>, ArrayList, so on) while enumerating it (basically comes exception that says so).

Now here is interesting part: SPListItemCollection allows to perform .Update() into it’s items without exception (and everything goes out fine). But when trying to do so for example SPListCollection, you’ll get the familiar error (altought error might be hidden in SharePoint Hive Logs or your own logging system) about modifying collection and enumeration not possible.

I thought to add this entry since I spoke with couple other SharePoint developers and found out that okay this is how things go but never had a second thought for the matter. I am sure that someone else can dig deeper into this and why this is so. And feel free to do so.

Visual Studio 2010 and SharePoint 2010: Content Type deployment error on second deployment round

sakarih — Wed, 15 Dec 2010 05:31:42 +0000

I have managed to hit my self at least twice now with this “smallish” problem with Visual Studio 2010 and SharePoint 2010. In Visual Studio 2010 you can add content type into SharePoint project and deployment goes easily through at first time, but later following error message pops up:

Error occurred in deployment step ‘Activate Features’: The content type with defined in feature {guid} was found in the current site collection or in a subsite.

Apparently this is quite common error, but I thought to add post from this to here if someone else manages to get this error and happens to find this blog at first.

And the solution: http://support.microsoft.com/kb/2022443 . On quick summary, solution can be as easy as retracting the solution, closing Visual Studio 2010 and starting studio again and doing the deployment. Sometimes there is needed to do extra tricks (like restarting SharePoint processes) but normally things are this easy with this particular problem.

SharePoint 2010: Workflow gets “stuck” in starting state

sakarih — Fri, 19 Nov 2010 05:40:35 +0000

I have been wondering seriously about the following problem. Some times workflow (created in Visual Studio 2010) stays in “Starting” state for at least 5 minutes. After some searching it was pointed out that Timer needs to trigger workflows if they are started programmatically and the logs state in a way same thing. However this does not occur when user starts workflow. I’ll be posting the solution for this problem when I’ll find it. The workflow in this case has some special features for which the immediate start is almost obligatory. I have also tried adding some delay in the workflow before calling the start, but no luck this far. This “starting” state was never a problem in SharePoint 2007.

Passed the 70-573 MCTS: SharePoint 2010 Application development certification

sakarih — Thu, 30 Sep 2010 06:03:05 +0000

I have been a bit silent now, but I want to say that I got my first SharePoint 2010 certification. I have been digging up stuff from SharePoint 2010 and doing some “conversion” from SP 2007 to SP2010. I’ll be posting some of my findings here and also I am now targeting to next SharePoint 2010 certification that will be 70-576.

Oh btw. my blog travelled from Live Spaces to here due to Microsoft discontinuing the Live Spaces.

Back in working

sakarih — Tue, 24 Aug 2010 06:14:02 +0000

Okay the summer holidays are over (saaaaaadly) and now it’s time to get back working. Luckily I was able to attend to 5 days course. Course topic was SharePoint 2010 application development and now I should atleast have some knowledge about that thing Transition from SharePoint 2007 to SharePoint 2010 is not too big, but there are certain things that need to be taken care of and now I am taking closer looks to this topic finally.

Certified ScrumMaster

sakarih — Wed, 23 Jun 2010 04:21:15 +0000

Okay I actually forgot to add this small posting here but I completed Certified ScrumMaster course and online test in last month (28th of May) and the verifying address is here:
http://www.scrumalliance.org/profiles/93432-sakari-hilama

And now I am close to summer holidays (tomorrow is the last work day for 6 weeks

SharePoint lookup columns across SharePoint Webs (SPWeb)

sakarih — Tue, 11 May 2010 04:33:47 +0000

Okay back to SharePoint sandboxes… I found a need to use SharePoint lookup columns between different SPWeb’s. By the normal UI of SharePoint, you are limited to use lookup columns just inside one web. Gladly in this case this is just a limitation of UI: you can write your own code to create new spfieldlookup and set its properties (like lookupwebid and lookuplistid) to anything you want in your Site Collection (apparently there might be even way to extend this through multiple site collections). This was a pleasent finding from SharePoint.

One another thingy was attachments in document library that was not as nice. Apparently SharePoint does not support in any way attachments in document library and it is hard coded barrier. So I might be working this topic more later on and thinking something like using SharePoint’s own logic (for a normal lists there is attachment logic like this: for SPListItem’s attachments, SharePoint creates folder named 1 or 10001 (same as SPListItem.ID on which you are putting your attachment), hides the folder from UI and voilá. Just wondering why this is not in use with Document Library. Some guys at the Internet did even their own Document Library schemas where they tried to enable this attachment functionality but no luck…