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

{% assign data = hash %}
{% assign data["foo"] = "bar" %}

{% action "event", topic: "user/foo/bar", data: data %}

JSON

{
  "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

{% 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 %}

JSON

{
  "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

{% 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 %}

JSON

{
  "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

shopify/orders/create
user/orders/unpaid_reminder

Code

{% 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

shopify/orders/create
user/orders/unpaid_reminder+1.day

Code

{% 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 %}