What are Custom Workflow Activities?

• Custom Workflow Activities can be added to an existing workflow to provide additional functionality in Workflows in CRM.
• Workflow Assemblies are included in steps of a workflow designer where input parameters can be provided to the same to carry out its designated functionality.
• Required Assemblies are Xrm.Sdk and Microsoft.Xrm.Sdk.Workflow
• Custom Workflow Activities can be written by deriving CodeActivity class in your workflow assembly.

• Custom Workflow Activities have Input and Output parameters that take and give out data to the workflows.
• protected override void Execute(CodeActivityContext context){ //Activity code} needs to be initialized to add functionality to a Workflow Assembly.

Registering a Custom Workflow Assembly.

• Custom Workflow Activities are registered in Plugin Registration Tool.
• They are not registered on a particular entity or on any message, like a Plugin.
• Registered Custom Workflow Assemblies then appear in the workflow step designer.
• We can specify the Name of the workflow and the WorkflowActivityGroupName in the Plugin Registration Tool as shown below.

Input and Output Parameters of a Workflow Assembly. 

• Here is an example of how we can declare an input parameter to a custom workflow assembly as follows:

• A default value can be provided along with declaring the Argument.
• Same way, we can add Output parameters to the custom workflow assembly as below.

• Or even declaring the Argument as both, input and output argument which is as follows:

Attributes and Microsoft Dynamics CRM Types.

• Bool
• DateTime
• Decimal
• Double
• EntityReference
• Int
• Money
• OptionSetValue
• String

So, that was a short and quick introduction about Custom Workflow Assembly! Hope this is helpful. 🙂