Adds Workflow Update to Samples (#99)

* Adds Workflow Update to Samples

* Move Workflow Update to single file

* Update the name of the file and run format

README.md

@@ -67,6 +67,7 @@ Some examples require extra dependencies. See each sample's directory for specif
 * [worker_specific_task_queues](worker_specific_task_queues) - Use unique task queues to ensure activities run on specific workers.
 * [worker_versioning](worker_versioning) - Use the Worker Versioning feature to more easily version your workflows & other code.
 
+
 ## Test
 
 Running the tests requires `poe` to be installed.

hello/README.md

@@ -41,3 +41,8 @@ Replace `hello_activity.py` in the command with any other example filename to ru
 * [hello_search_attributes](hello_search_attributes.py) - Start workflow with search attributes then change while
   running.
 * [hello_signal](hello_signal.py) - Send signals to a workflow.
+* [hello_update](hello_update.py) - Send a request to and a response from a client to a workflow execution.
+
+Note: To enable the workflow update, set the `frontend.enableUpdateWorkflowExecution` dynamic config value to true.
+
+    temporal server start-dev --dynamic-config-value frontend.enableUpdateWorkflowExecution=true

hello/hello_update.py

@@ -0,0 +1,53 @@
+import asyncio
+
+from temporalio import workflow
+from temporalio.client import Client
+from temporalio.worker import Worker
+
+
+@workflow.defn
+class GreetingWorkflow:
+    is_complete = False
+
+    @workflow.run
+    async def run(self) -> str:
+        await workflow.wait_condition(lambda: self.is_complete)
+        return "Hello, World!"
+
+    @workflow.update
+    async def update_workflow_status(self) -> str:
+        self.is_complete = True
+        return "Workflow status updated"
+
+
+async def main():
+    client = await Client.connect("localhost:7233")
+
+    # Run a worker for the workflow
+    async with Worker(
+        client,
+        task_queue="update-workflow-task-queue",
+        workflows=[GreetingWorkflow],
+    ):
+        # While the worker is running, use the client to start the workflow.
+        # Note, in many production setups, the client would be in a completely
+        # separate process from the worker.
+        handle = await client.start_workflow(
+            GreetingWorkflow.run,
+            id="hello-update-workflow-id",
+            task_queue="update-workflow-task-queue",
+        )
+
+        # Perform the update for GreetingWorkflow
+        update_result = await handle.execute_update(
+            GreetingWorkflow.update_workflow_status
+        )
+        print(f"Update Result: {update_result}")
+
+        # Get the result for GreetingWorkflow
+        result = await handle.result()
+        print(f"Workflow Result: {result}")
+
+
+if __name__ == "__main__":
+    asyncio.run(main())