CODEWITHSUNDEEP
workflowworkflow-foundation-4
JasonRShaver
JasonRShaver

Reputation: 4394

How to tell the Activity type when loading a persisted workflow

Question:

Is there an easy way to find out what Activity Type was used to create a workflow?

Background:

I am writing my own WorkflowApplication based Windows Workflow 4 hosting engine and I am having some issues trying to load persisted workflows out of the database. I am using the WorkflowApplication.Load(Guid) method to start the workflow, but this requires me to already create the WorkflowApplication.

Looking at the SqlWorkflowInstanceStore databases, I don't see the type name stored anywhere and I don't see an easy to to associate it short of making another table myself just to store that information.

Upvotes: 1

Views: 756

Answers (2)

Damir Arh
Damir Arh

Reputation: 17855

I guess you have 2 options for doing that, neither of them optimal:

  • You could use promoted properties as Maurice already suggested to store the info in the InstancePromotedPropertiesTable and avoid having to create your own table. There's a nice article on MSDN.
  • if you decide to create your own table, I'd suggest you implement a PersistenceIOParticipant. Check out the sample, you could always store the type name or your XAML instead of the path.

Upvotes: 1

Maurice
Maurice

Reputation: 27632

When you are using workflow services the relative URL is used to determine if a WorkflowServiceHost owns the workflow instance, this is done through the ServiceDeploymentsTable table in the database. There is no similar mechanism when you are using a WorkflowApplication so you have to roll your own.

One thing you could do is use property promotion to store the type in the InstancePromotedPropertiesTable. It will save you from creating a new table but is hardly an ideal way of solving the problem.

Upvotes: 2

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