Event

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Event
The Event action is for generating custom events in the User event domain. It's used to queue up follow-up work, either immediately or in the future, and can be useful when designing complex workloads, separating work between tasks.
Events generated by this action may be responded to by other tasks, or by the task that generated this action.
Events generated by this action are child events of the event responsible for the current action.
Options
Option
Description
topic
Required; a string specifying an event topic of the form "user/*/*"
data
Required; any JSON value (including null), to be used as the event data
run_at
Optional; a Unix timestamp integer, or any string that can be parsed as a time
task_ids
Optional, cannot be used with task_id; an array of task UUID strings, specifying which tasks are allowed to respond to this event
task_id
Optional, cannot be used with task_ids; a string containing a single task UUID, specifying which task is allowed to respond to this event
Notes
If a run_at value specifies a time in the past, the new event will be run immediately.
Tasks specified by task_ids or task_id must subscribe to the event topic being used. As with all subscriptions, offsets may be used, and will be respected.
Examples
Using the Event tag
Liquid
JSON
{% assign data = hash %}
{% assign data["foo"] = "bar" %}
​
{% action "event", topic: "user/foo/bar", data: data %}
{
  "action": {
    "type": "event",
    "options": {
      "topic": "user/foo/bar",
      "data": {
        "foo": "bar"
      }
    }
  }
}
Using specific tasks
Using task_id
Uses the optional task_id parameter to control which singular task is allowed to respond to this event.
That task must be subscribed to the event topic being used.
Liquid
JSON
{% assign data = hash %}
{% assign data["foo"] = "bar" %}
{% assign task_id = "293b7040-6689-4eb1-8b5d-64f4d33eb2ae" %}
{% comment %} For multiple tasks use `task_ids` {% endcomment %}
​
{% action "event", topic: "user/foo/bar", data: data, task_id: task_id %}
{
  "action": {
    "type": "event",
    "options": {
      "topic": "user/foo/bar",
      "data": {
        "foo": "bar"
      },
      "task_id": "293b7040-6689-4eb1-8b5d-64f4d33eb2ae"
    }
  }
}
Notes
You can limit a task to itself by referencing it's own task.id
See options to have a user configurable input instead of hardcoding the task id(s).
Scheduling future events
Using run_at
This example uses the run_at option to run the task at a later scheduled time.
Liquid
JSON
{% assign one_day_in_seconds = 60 | times: 60 | times: 24 %}
​
{% action "event" %}
  {
    "topic": "user/foo/bar",
    "task_id": {{ task.id | json }},
    "run_at": {{ "now" | date: "%s" | plus: one_day_in_seconds | json }},
    "data": {
      "foo": "bar"
    }
  }
{% endaction %}
{
  "action": {
    "type": "event",
    "options": {
      "topic": "user/foo/bar",
      "task_id": "293b7040-6689-4eb1-8b5d-64f4d33eb2ae",
      "run_at": 1613158259,
      "data": {
        "foo": "bar"
      }
    }
  }
}
This task emails a customer daily until their order is paid. It works by scheduling a follow-up run of the same task, one day in the future, using the run_at option.
Subscriptions
Code
shopify/orders/create
user/orders/unpaid_reminder
{% if event.preview %}
  {% assign order = hash %}
  {% assign order["id"] = 1234568790 %}
  {% assign order["name"] = "#1234" %}
{% elsif event.topic == "user/orders/unpaid_reminder" %}
  {% assign order = shop.orders[event.data.order_id] %}
{% endif %}
​
{% unless order.financial_status == "paid" %}
  {% action "email" %}
    {
      "to": {{ order.email | json }},
      "reply_to": {{ shop.customer_email | json }},
      "subject": "Order {{ order.name }} still needs to be paid",
      "body": "Please get in touch, stat!",
      "from_display_name": {{ shop.name | json }}
    }
  {% endaction %}
​
  {% assign one_day_in_seconds = 60 | times: 60 | times: 24 %}
​
  {% action "event" %}
    {
      "topic": "user/orders/unpaid_reminder",
      "task_id": {{ task.id | json }},
      "run_at": {{ "now" | date: "%s" | plus: one_day_in_seconds | json }},
      "data": {
        "order_id": {{ order.id | json }}
      }
    }
  {% endaction %}
{% endunless %}
Using subscription offsets
This task emails a customer daily until their order is paid. It works by firing the follow-up event immediately, using a subscription offset to respond to it a day later.
Subscriptions
Code
shopify/orders/create
user/orders/unpaid_reminder+1.day
{% if event.preview %}
  {% assign order = hash %}
  {% assign order["id"] = 1234568790 %}
  {% assign order["name"] = "#1234" %}
{% elsif event.topic == "user/orders/unpaid_reminder" %}
  {% assign order = shop.orders[event.data.order_id] %}
{% endif %}
​
{% unless order.financial_status == "paid" %}
  {% action "email" %}
    {
      "to": {{ order.email | json }},
      "reply_to": {{ shop.customer_email | json }},
      "subject": "Order {{ order.name }} still needs to be paid",
      "body": "Please get in touch, stat!",
      "from_display_name": {{ shop.name | json }}
    }
  {% endaction %}
​
  {% assign one_day_in_seconds = 60 | times: 60 | times: 24 %}
​
  {% action "event" %}
    {
      "topic": "user/orders/unpaid_reminder",
      "task_id": {{ task.id | json }},
      "data": {
        "order_id": {{ order.id | json }}
      }
    }
  {% endaction %}
{% endunless %}
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Options
Notes
Examples
Using the Event tag
Using specific tasks
Scheduling future events