Capability to Select a 'Starting Step' for a Workflow

[jamshally]

I am interested in the ability of initiating a workflow at a 'downstream' Step (a Step other than the first). This would greatly reduce the number of workflow definitions needed to support some related workflow scenarios.

Has this feature/capability been considered, and ruled out/in for any reason?

I'd be happy to try and contribute a PR if this was straight forward development.

Looking at the code I see a method in ExecutionPointerFactory called BuildGenesisPointer. Is the introduction of this capability as simple as allowing a start stepId (or name, or index) to be passed into this (via WorkflowController.StartWorkflow), or am I missing some difficulties with this?

public ExecutionPointer BuildGenesisPointer(WorkflowDefinition def)
        {
            return new ExecutionPointer
            {
                Id = GenerateId(),
                StepId = 0, // <------------------------------
                Active = true,
                Status = PointerStatus.Pending,
                StepName = def.Steps.FindById(0).Name
            };
        }

As an aside, thanks for your efforts building, sharing, and maintaining in this library!

[jamshally]

For the benefit of others, we finally achieved this via WorkflowStepMiddleware. The following code snippet demonstrates the fundamental part of this approach:

// ----------------------------------------------------
// Inside IWorkflowStepMiddleware.HandleAsync
// ----------------------------------------------------

// Retrieve the workflow definition using the current workflow's definition ID and version.
var definition = _workflowRegistry.GetDefinition(context.Workflow.WorkflowDefinitionId, context.Workflow.Version);

// Find the designated start step within the workflow definition based on an external identifier.
var startStep = definition.Steps.Find(x => x.ExternalId == workflowTargetStartStep.StartStepId);

// Check if the current step's ID is less than the start step's ID, which indicates that
// the current step should be skipped and the workflow should proceed to the start step.
if (context.Step.Id < startStep.Id)
{
    // Return the 'Next' execution result to move the workflow execution forward.
    return Task.FromResult(ExecutionResult.Next());
}

public interface IWorkflowTargetStartStep
{
    string? StartStepId { get; set; }
}