Event log plugins

They are used to trigger actions following events generated by Paella Player. These events can be triggered by automatic actions, for example, the Events.TIMEUPDATE event, or by user actions, such as Evens.PLAY. It is also possible to capture custom events. See the events document for more information.

Create an event log plugin

To implement an event log plugin, you must to overwrite the property get events() and the method async onEvent(event, params).

get events(): returns an array with the events that you want to handle by the onEvent() function.

async onEvent(event, params): this function is invoked whenever one of the events returned by get events() is triggered by the player.

import { Events, EventLogPlugin } from 'paella-core';

export default class TestEventLogPlugin extends EventLogPlugin {
  get events() {
    return [
      Events.PLAY,
      Events.PAUSE,
      Events.TIMEUPDATE
    ]
  }
  
  async onEvent(event, params) {
    console.log(event);
    console.log(params);
  }
}

Track user actions

It is possible to use an event plugin together with a data plugin to implement user tracking. The procedure consists of writing data to a context that we predefine for this purpose, for example userTracking:

export default class MyUserTrackerEventLogPlugin extends EventLogPlugin {
  ...
  
	async onEvent(event, params) {
    await this.player.data.write(
      'userTracking', 
      { id: this.player.videoId }, 
      { event: event }
    );
  }
}

Then you just have to define a data plugin that responds to the userTracking context to write the events to any system. We could have two different data plugins: one for Google Analytics and one for Matomo:

es.upv.paella.matomoDataPlugin.js:

export default class MatomoDataPlugin extends DataPlugin {
  async write(context, id, data) {
    // Write Matomo event for the video `id`
    ...
  }
}

es.upv.paella.analyticsDataPlugin.js:

export default class AnalyticsDataPlugin extends DataPlugin {
  async write(context, id, data) {
    // Write Analytics event for the video `id`
    ...
  }
}

In the player configuration is where we define the priority level of each data plugin, to determine which of the analysis systems we are going to use, depending on the plugin priority:

{
  "plugins": {
    ...
    "es.upv.paella.matomoDataPlugin": {
      "enabled": true,
      "order": 0
    },
    "es.upv.paella.analyticsDataPlugin": {
      "enabled": true,
      "order": 1
    }
  }
}