Question

[hm-ch]

Hi @sfmskywalker

First of all i would like to thank you about the great job.
Afterr publishing the workflow using workflow designer, how can I start a new workflow instance based on WorkflowDefinitionId or Workflow Name.

Thanks

[sfmskywalker]

Thanks!

To start a workflow, you have two options:

1. Via the REST API
2. Using C# code (that you executed from within the workflow server application).

API

To use the REST API, you need to have a workflow definition ID. When you have it (e.g. 7b626d125eae49ce99e30b4f223322aa), you can execute the workflow like this:

curl --location --request POST 'https://localhost:11000/v1/workflows/7b626d125eae49ce99e30b4f223322aa/execute' \
--header 'Content-Type: application/json' \
--data-raw '{
}'

That will execute the workflow synchronously. If you want to execute the workflow from a background job instead (so that the HTTP call returns even before the workflow starts, you can dispatch the workflow instead, like this:

curl --location --request POST 'https://localhost:11000/v1/workflows/7b626d125eae49ce99e30b4f223322aa/dispatch' \
--header 'Content-Type: application/json' \
--data-raw '{
}'

For either call, you can provide input to the workflow by including a JSON payload with the "input" field.
For example:

curl --location --request POST 'https://localhost:11000/v1/workflows/7b626d125eae49ce99e30b4f223322aa/dispatch' \
--header 'Content-Type: application/json' \
--data-raw '{
    "input": "Demo Input"
}'

C#

If you want to execute a workflow programmatically from within the workflow server, then you use the IWorkflowLaunchpad that the REST APIs use internally.

For example, to execute a workflow synchronously:

var workflowDefinitionId = "7b626d125eae49ce99e30b4f223322aa";
await _workflowLaunchpad.FindAndExecuteStartableWorkflowAsync(workflowDefinitionId);

To dispatch the workflow, you need to perform two steps: find the workflow to dispatch, then dispatch:

var startableWorkflow = await _workflowLaunchpad.FindStartableWorkflowAsync(workflowDefinitionId);
var result = await _workflowLaunchpad.DispatchStartableWorkflowAsync(startableWorkflow);

[Nokecy]

Use c# , What is the difference between synchronously and dispatch @sfmskywalker

[sfmskywalker]

Synchronously

When executing a workflow synchronously, it means that the when the call to e.g. await _workflowLaunchpad.FindAndExecuteStartableWorkflowAsync(workflowDefinitionId) completes. the workflow will have executed (until the first blocking activity or until the workflow reached the end).

Dispatch

When dispatching a workflow for execution, it means that the call to e.g. var result = await _workflowLaunchpad.DispatchStartableWorkflowAsync(startableWorkflow) completes before the workflow has even started.

What happens inside this call is that it will schedule a message onto a queue and then returns control to the caller.
Meanwhile, the message will (eventually) be picked up from a background job (a queue worker, aka consumer) that will then execute the workflow.