Action Types

An action type library module is intended to take an action–any action. What this action does is entirely up to you. Would you like to send a beacon or perhaps transform some data from the event?

Let’s assume we want to forward some data to a third-party party endpoint. Our module may look like this:

module.exports = (context) {
  const { arc, utils } = context;
  const { fetch } = utils;
  const { event: { xdm } } = arc;
  return fetch('http://someendpoint.com', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(xdm)
  })
};

Now what if we wanted to make the endpoint configurable by the Launch user? In our view we would allow the user to input an endpoint and then save the endpoint to the settings object. The object might look something like this:

{
  "endpoint": "http://someendpoint.com"
}

In order to operate on the user-defined endpoint, our module would need to change to this:

module.exports = (context) {
  const { arc, utils } = context;
  const { fetch } = utils;
  const { event: { xdm } } = arc;
  const  { endpoint } = settings;

  return fetch(endpoint, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(xdm)
  })
};

Action Result

The result returned by a action module can be anything. If the action needs to execute an asynchronous task, you can return a Promise that returns whatever result you want once the promise is resolved.

The action result is stored inside ruleStash key that is made available to all the modules through the library module context parameter(context.arc.ruleStash). You can learn more about ruleStash here.

Library Module Context

All action modules have access to a context variable that is provided when the module is called. You can learn more here.