+++
title = "Emitting events"
weight = 17
+++

## Overview

* For timeouts, you will change the workflow to emit information about order timeouts.
* You will also add an event once the order is finished.
* You will modify the workflow to emit an event if the shop is not ready to receive an order.
* You will test the new workflow and see the input and output payloads.

After this section, you will have a workflow that emits several new events.

## 1. Emitting a time out event.

In this section, you add an EventBridge PutEvents state that emits an event if either the customer or barista times out an order. You have already created the logic to handle time outs so only need to use EventBridge to emit an event.

### Step-by-step instructions ##

1. 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**.

2. From the left-hand menu, select *State machine* and choose **OrderProcessorWorkflow** from the list. Choose **Edit**.

![Choose Edit](../images/se-mod1-open1.png)

3. On the next page, choose **Workflow Studio** to open the workflow in the designer.

4. With the *Actions* tab selected on the left, enter `putevents` in the search bar. Drag the *Amazon EventBridge PutEvents* action from the list to between the *Customer timeout* and End states in the designer.

![Drag PutEvents to designer](../images/se-mod1-wait15.png)

5. With the state selected, the attribute panel on the right shows the configuration for this state. In the *Configuration tab*:
- For *State name*, enter `Emit - error timeout`.
- Ensure Wait for callback is **unchecked**.
- For *API Parameters*, paste the following JSON:

```
{
  "Entries": [
    {
      "Detail": {
        "Message": "The order timed out. Step Functions waits a set amount of time (5 minutes for a customer, 15 minutes for a barista), no action was taken and so the order is ended.",
        "userId.$": "$.detail.userId",
        "orderId.$": "$.detail.orderId",
        "cause.$": "$.cause"
      },
      "DetailType": "OrderProcessor.OrderTimeOut",
      "EventBusName": "Serverlesspresso",
      "Source": "awsserverlessda.serverlesspresso"
    }
  ]
}
```

![Event configuration](../images/se-mod1-wait16.png)

6. Connect the *Barista timeout* pass state to the *Emit - error timeout* state. Choose the *Barista timeout* state to open the attribute panel on the right. In the *Configuration* tab, change *Next state* to *Emit - error timeout*.

![Drag UpdateItem to designer](../images/se-mod1-wait17.png)

## 2. Emitting an order finished event.

In this section, you add an EventBridge PutEvents state that emits a final event when the order has finished, and the workflow has completed.

### Step-by-step instructions ##

1. With the *Actions* tab selected on the left, enter `putevents` in the search bar. Drag the *Amazon EventBridge PutEvents* action from the list to between the Pass and End states in the designer.

![Drag UpdateItem to designer](../images/se-mod1-wait18.png)

2. With the state selected, the attribute panel on the right shows the configuration for this state. In the *Configuration tab*:
- For *State name*, enter **Emit - order finished**.
- Ensure *Wait for callback* is **unchecked**.
- For *API Parameters*, paste the following JSON:

```
{
  "Entries": [
    {
      "Detail": {
        "Message": "The order has reached the end of the workflow, and so a final event is emitted to alert other services to this.",
        "userId.$": "$.detail.userId",
        "orderId.$": "$.detail.orderId"
      },
      "DetailType": "OrderProcessor.orderFinished",
      "EventBusName": "Serverlesspresso",
      "Source": "awsserverlessda.serverlesspresso"
    }
  ]
}
```
![Drag UpdateItem to designer](../images/se-mod1-wait19.png)

## 3. Updating the shop not ready event.

In this section, you update the EventBridge PutEvents state that was created earlier to emit an event if the shop is closed or there is no capacity to accept new orders.

### Step-by-step instructions ##

1. Choose the *PutEvents* state between the *Shop open?* and *End* states in the designer.

![Drag UpdateItem to designer](../images/se-mod1-wait20.png)

2. With the state selected, the attribute panel on the right shows the configuration for this state. In the *Configuration tab*:
- For *State name*, enter **Emit - Shop not ready**.
- For *Wait for callback*, **uncheck** this box.
- For *API Parameters*, paste the following JSON:

```
{
  "Entries": [
    {
      "Detail": {
        "Message": "The Step functions workflow checks if the shop is open and has capacity to serve a new order by invoking a Lambda function that queries the Shop config service. The shop was not ready, and so a 'not ready' event is emitted to cancel the current order.",
        "userId.$": "$.detail.userId"
      },
      "DetailType": "OrderProcessor.ShopUnavailable",
      "EventBusName": "Serverlesspresso",
      "Source": "awsserverlessda.serverlesspresso"
    }
  ]
}
```
![Drag UpdateItem to designer](../images/se-mod1-wait20.png)

3. Choose **Apply and exit**. In the Edit page, choose **Save**.

4. In the *IAM role* popup, choose **Save anyway**.

![Drag UpdateItem to designer](../images/se-mod1-wait22.png)

### Recap

- In this section, you configured the workflow to emit events for timeouts, order completion, or if the store is not ready to receive orders because it's closed.

### Next steps

Next, you'll test the workflow to see how the execution path changes depending on the shop state and barista capacity.