Extension:EventLogging/en

The EventLogging extension makes it possible to collect structured data on how users interact with MediaWiki sites.

Features

 * EventLogging supports client-side logging from JavaScript and server-side logging from PHP.
 * Logging behavior can be dynamically configured using.
 * The events are JSON objects defined by versioned JSONSchemas stored in a schema git repository.
 * The extension does not include any back-end code for transporting, parsing, or loading these events. A separate service, EventGate, implements this functionality and deals with inserting events into Kafka. Events are then persisted in downstream datastores (e.g. Hive) via various ingestion pipelines. The details of these components are specific to Wikimedia Foundation's configuration.

EventLogging at Wikimedia
The Wikimedia Foundation uses the EventLogging extension as part of a broader system for collecting, aggregating, storing, and analyzing user data within the limits set out by our privacy policy and data retention guidelines.

This page is about general use of the EventLogging extension. The Wikimedia Foundation uses EventLogging with WMF specific backend components and schema repositories. For Wikimedia specific and maintained documentation, see Analytics/Systems/EventLogging and Event Platform.

Configuring the schema location
By default, the extension will look for schemas on Meta-Wiki. The relevant default settings are:

To use local schemas, or schemas from the central wiki of your own wikifarm, you need to override these. E.g. to use the  namespace of the local wiki, set

(and ensure the user account that will create the schemas is autoconfirmed).

Logging events using EventLogging

 * - to developing and deploying EventLogging schemas, and more
 * - tips and suggestions for developers writing code to log events

Developer setup
As a developer, you will want to set up and use EventLogging on your development wiki to simulate its use in production.

Using Docker
See 

Using mediawiki-vagrant
If you develop using mediawiki-vagrant, everything you need is encapsulated in the  role. To enable it, run:

For JavaScript development
If working on the JavaScript client, you'll need to install dependencies with  from the folder you're developing in. Then you can use  to run ESLint for example. The "How to run tests" section below points out how to see JavaScript test results.

When adding the parameter  to the URL, the console in the browser's devtools will show the event logging being triggered.

How to run tests
There are PHP tests, Python tests, and JavaScript tests.

To run JavaScript tests, visit Special:JavaScriptTest/qunit on your development wiki. (See .)

To run PHP tests, we use PHPUnit. Make sure it is installed, then: