Step Back in Elsa

[mohdjarwan]

How can I move the workflow back to a previous activity in Elsa and continue execution?
I tried scheduling the previous activity, but it doesn’t run because it has already been completed.
What is the correct way to handle this?

[sfmskywalker]

The official way is to use the Alterations API, which lets you define an alterations plan and execute it. There are different types of alterations, and the intentions be interested in is the ScheduleActivy alteration.

[mohdjarwan]

Thanks spike,
I have two different approaches to schedule an activity in Elsa 3, and I want to understand which one is better in terms of performance and correctness.
Method A - Alteration Code:
var alterations = new List<IAlteration> {
new ScheduleActivity(){ ActivityId= "c84cabf584f6e89b" }
};
var workflowInstanceId = context.WorkflowExecutionContext.Id;
var serviceProvider = context.GetRequiredService<IServiceProvider>();
var runner = serviceProvider.GetRequiredService<IAlterationRunner>();
var alterationsResult = await runner.RunAsync(workflowInstanceId, alterations, CancellationToken.None);
var dispatcher = serviceProvider.GetRequiredService<IAlteredWorkflowDispatcher>();
await dispatcher.DispatchAsync(alterationsResult, CancellationToken.None);
}

Method A - Schedule Activity:
// 3. Schedule the target activity to run next
var phoneVariable = new Variable("RecipientPhone", context.Get(RecipientPhone));
var options = new ScheduleWorkOptions
{
Variables = new List<Variable> { phoneVariable }
};
await context.ScheduleActivityAsync(targetActivity, options);
return ValidationResult.Success();