Order Manager workflow
The OrderManager workflow is deployed with the initial core setup. It is triggered by an API call from the front-end applications. It persists updates to the order entry in the serverlesspresso-order-table in DynamoDB. It also retrieves the current TaskToken and resumes the orderProcessor workflow.
The OrderManager workflow handles 4 different tasks:
- Customer put: This is when a customer has submitted a drink order, the workflow will sanitize this order against the current menu to make sure it is a valid selection, and then update the serverlesspresso-order-table with the order information.
- Cancel order: This path is taken when either the barista or the customer decide to cancel an order.
- Complete Order: This path is taken when the barista chooses the Complete button on the barista app.
- Make / Unmake: This path is taken when the barista claims an order from the barista app, or when the barista moves the order back into the order pending state.
The workflow path is initially decided by a Choice state which queries the $.action field, and branches accordingly. This is shown below:
Testing the “OrderManager” workflow.
Resume the OrderProcessor workflow by running the OrderManager workflow:
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Go to the Step Functions console. From the AWS Management Console, select Services then select Step Functions under Application Integration. Make sure your region is correct.
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Select State machines from the left panel, then choose OrderManagerStateMachine. Choose Start execution.
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Enter the following into the Input text area and choose Start execution:
{"action":"","body":{"userId":"1","drink":"Cappuccino","modifiers":[],"icon":"barista-icons_cappuccino-alternative"},"orderId":"1","baristaUserId":"3"}
See how has affected the OrderProcessor workflow:
- Choose State machines, from the breadcrumbs at the top of the page.
- Choose the OrderProcessor workflow, and then chose the most recent execution:
The TaskToken has been used to send a ‘TaskSuccess’ call to the OrderProcessor. The workflow has resumed and progressed to the next wait step.
This was done by the Resume Order Processor step.
See what happens if an item is ordered that is not on the menu:
- Go to the OrderManagerStateMachine in the Step Functions console.
- Choose Start execution, enter the following into the input text area and choose Start execution:
{"action":"","body":{"userId":"1","drink":"milkshake","modifiers":[],"icon":"barista-icons_cappuccino-alternative"},"orderId":"1","baristaUserId":"3"}
This input payload includes a drink that is not available on the menu "drink":"milkshake".
The workflow takes a different execution path from the Is Order Valid? state, and so the order is not entered into the serverlesspresso-order-table.