Add Listener

3 min

Listen to a snippet lifecycle event.

Description

Listen to a specific event from somewhere in the snippet's execution. Your handler function will be invoked for each applicable lifecycle event that occurs after the handler is registered. It is not retroactively invoked for events that may have occurred prior to handler registration.

You can listen to the following types of events:

window.optimizelyEdge.push(addListener);

window.optimizelyEdge.push({
  "type": "addListener",
  "filter": {
    "type": "lifecycle",
    "name": "initialized"
  },
  "handler": function(event) {
    console.log("Project " + window["optimizely"].get("data").projectId + " is initialized");
  }
});

Parameters

This table provides general information about required and optional parameters.

Parameter	Type	Description
addListener required	object	An object with the type field set to addListener. The other fields are the function arguments.
addListener.type required	string	The argument indicating that you are using the addListener function.
addListener.filter optional	object	By setting a filter, you can define for which type of events or what category of events the handler is called.
addListener.handler optional	function	The function that will be called when the event occurs.
addListener.filter.type required	string	The category of an event. Possible values: lifecycle and analytics.
addListener.filter.name optional	string	The name of the event type. The value can be: campaignDecided, pageActivated, initialized, originsSynced, or trackEvent.