R – Workflow Foundation: using workflow tasks without SharePoint

workflow-foundation

I've previously done WF workflows hosted by SharePoint sites. We currently have to develop a pretty complex workflow for a vanilla ASP.NET application that, alas, does not run in a SharePoint context.

I've noticed that when I create a 'plain' WF workflow in VS2008, I don't have the CreateTask, onTaskChanged etc activities. I suppose this is because all the task API is provided by the extra MOSS layer.

My question is, is there any library that implements task-oriented stuff for WF or do we have to roll our own?

Best Answer

WF (without SharePoint) doesn't provide such functionality out of the box. I'm not aware of any library that provides task/inbox functionality, so we have built our own.

The tasks are created by a custom activity. The workflows will be signaled using plain WF 3.5 receive activities which cause the workflows to wait for a signal from any WF external GUI.

There is a sample from Microsoft that shows something similar, though it's not using WF services.

Related Solutions

How to implement reject in parallel approval workflow

After being faced with the same problem and spending a lot of time researching and trying out different options, I think I found a really good solution. I'm posting it here for posterity.

Create a custom activity that extends SequenceActivity called ReviewActivity
The ReviewActivity includes the typical CreateTask -> While -> OnTaskChanged -> CompleteTask scenario
In my workflow, I have a Replicator that is creating many instances of the ReviewActivity (and thus many Tasks).
The replicator implements an UntilCondition that checks to see if a task was rejected (this is set in the ChildCompleted)
After the Replicator, I have an UpdateAllTasks to close the remaining tasks

If you have any experience with this scenario at all, you are getting ready to tell me that UpdateAllTasks also updates the originally rejected task since the "CompleteTask" has not been persisted to the database yet. The magic is in an attribute that you can define for the custom activity (ReviewActivity) called PersistOnClose.

[Designer(typeof(ActivityDesigner), typeof(IDesigner))]
[PersistOnClose]
public partial class ReviewActivity : SequenceActivity

This attribute ensures that once the ReviewActivity is complete, all changes are persisted to the database. Since the last activity in the ReviewActivity is the "CompleteTask", the task is saved to the DB. Therefore, the UpdateAllTasks will not touch it.

I hope this helps someone.

R – Sharepoint workflow Tasks attachment

Assuming you want to get the actual attachment (as opposed to a link to the attachment) you will probably have to get it from the library directly:

http://www.binarywave.com/blogs/eshupps/Lists/Posts/Post.aspx?ID=26

From the above:

SPFolder folder = web.Folders["Lists"].SubFolders[list.Title].SubFolders["Attachments"].SubFolders[listitem.ID.ToString()];

foreach (SPFile file in folder.Files)
{
  // Something useful here
}

Best Answer

Related Solutions

How to implement reject in parallel approval workflow

R – Sharepoint workflow Tasks attachment

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