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mw.eventLog

Client-side EventLogging API, including pub/sub subscriber functionality.

The main API is mw.eventLog.logEvent. This is set up as a listener for event-namespace topics in mw.track. Sampling utility methods are available in two flavors. Other methods represent internal functionality, exposed only to ease debugging code and writing tests.

Classes

BackgroundQueue

This class enables pending callbacks to fire all at once, on a synchronized schedule instead of one by one.

Schema

The class allows inheriting classes to log events based on a sampling rate if sampling is enabled.

Methods

enqueue(callback)static #

Add a pending callback to be flushed at a later time by the background queue.

Parameters:

Name Type Description
callback function

to enqueue and run when the queue is processed
Source:

Returns:

undefined

Add a pending callback to be flushed at a later time by the background queue.

getUserEditCountBucket(editCount) → {string|null}static #

Provide the user's edit count as a low-granularity bucket name.

Parameters:

Name Type Description
editCount number | null

User edit count, or null for anonymous performers.
Source:

Returns:

null for anonymous performers.

Do not use this value in conjunction with other edit count bucketing, or you will deanonymize users to some degree.

Type
string | null
Provide the user's edit count as a low-granularity bucket name.

logEvent(schemaName, eventData) → {jQuery.Promise}static #

Construct and transmit to a remote server a record of some event having occurred. Events are represented as JavaScript objects that conform to a JSON Schema. The schema describes the properties the event object may (or must) contain and their type. This method represents the public client-side API of EventLogging.

Parameters:

Name Type Description
schemaName string

Canonical schema name.
eventData Object

Event object.
Source:

Returns:

jQuery Promise object for the logging call.

Type
jQuery.Promise

Construct and transmit to a remote server a record of some event having occurred.

logFailure(schemaName, errorCode)static #

Increment the error count in statsd for this schema.

Should be called instead of logEvent in case of an error.

Parameters:

Name Type Description
schemaName string
errorCode string
Source:
Increment the error count in statsd for this schema.

pageviewInSample(populationSize) → {boolean}static #

Determine whether the current event is sampled given a sampling ratio per pageview.

Parameters:

Name Type Description
populationSize number

One in how many should be included. 0 means nobody, 1 is 100%, 2 is 50%, etc.
Source:

Returns:

Type
boolean

Determine whether the current event is sampled given a sampling ratio per pageview.

sendBeacon(url)static #

Make a "fire and forget" HTTP request to a specified URL.

In older browsers that lack the Beacon API (navigator.sendBeacon), this falls back to a detached Image request.

Parameters:

Name Type Description
url string

URL to request from the server.
Source:
Make a "fire and forget" HTTP request to a specified URL.

sessionInSample(populationSize) → {boolean}static #

Determine whether the current sessionId is sampled given a sampling ratio. This method is deterministic given same sampling rate and sessionId, so sampling is sticky given a session and a sampling rate

Parameters:

Name Type Description
populationSize number

One in how many should be included. 0 means nobody, 1 is 100%, 2 is 50%, etc.
Source:

Returns:

Type
boolean
Determine whether the current sessionId is sampled given a sampling ratio.