quickstarts/tutorials/workflow/csharp/child-workflows

Child Workflows

This tutorial demonstrates how a workflow can call child workflows that are part of the same application. Child workflow can be used to break up large workflows into smaller, re-usable parts. For more information about child workflows see the Dapr docs.

Inspect the code

Open the ParentWorkflow.cs file in the tutorials/workflow/csharp/child-workflows/ChildWorkflows folder. This file contains the definition for the workflow.

The workflow iterates over the input array and schedules the ChildWorkflow for each of the input elements. The ChildWorkflow contains a sequence of two activities.

Parent workflow

graph LR
   SW((Start
   Workflow))
   subgraph for each word in the input
    GWL[Call child workflow]
   end
   ALL[Wait until all tasks
   are completed]
   EW((End
   Workflow))
   SW --> GWL
   GWL --> ALL
   ALL --> EW

Child workflow

graph LR
   SW((Start
   Workflow))
   A1[Activity1]
   A2[Activity2]
   EW((End
   Workflow))
   SW --> A1
   A1 --> A2
   A2 --> EW

Run the tutorial

1. Use a terminal to navigate to the tutorials/workflow/csharp/child-workflows folder.

2. Build the project using the .NET CLI.

   dotnet build ./ChildWorkflows/
   

3. Use the Dapr CLI to run the Dapr Multi-App run file

   ```bash
   

   dapr run -f .

   <!-- END_STEP -->
   
   

4. Use the POST request in the childworkflows.http file to start the workflow.

   The input of the workflow is an array with two strings:

   [
       "Item 1",
       "Item 2"
   ]
   

5. Use the GET request in the childworkflows.http file to get the status of the workflow.

   The expected serialized output of the workflow is an array with two strings:

   "[\"Item 1 is processed as a child workflow.\",\"Item 2 is processed as a child workflow.\"]"
   

6. Stop the Dapr Multi-App run process by pressing Ctrl+C.