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Glean.js

Uploaders

uploadEnabled

This value controls whether or not Glean will upload pings. You can set this value two different ways:

  • During initialization (as the second parameter): Glean.initialize("app-name", true);
  • Programmatically, while the app is running: Glean.setUploadEnabled(false);

Uploaders

sendbeacon_fallback

The default uploader used by Glean.js.

This uploader tries to use sendBeacon first. If the API call fails or sendBeacon isn’t available, Glean.js will try and use the fetch uploader instead.

sendBeacon

The preferred uploader of Glean.js. Using sendBeacon allows us to more accurately trigger API calls whenever pages are unloading.

fetch

Glean.js will automatically use the fetch API whenever debug values are set. Debug Tags and Source Tags are sent through custom headers, which isn’t possible using sendBeacon.

Configuring a custom uploader

You are able to configure a custom uploader in Glean.js.

Custom uploader

import Glean from '@mozilla/glean/<platform>';
import { Uploader, UploadResult, UploadResultStatus } from '@mozilla/glean/uploader';


/**
 * My custom uploader implementation
 */
export class MyCustomUploader extends Uploader {
  async post(url: string, body: string, headers): Promise<UploadResult> {
    // My custom POST request code
  }
}


Glean.initialize(
  'my-app-id',
  // Here, `isTelemetryEnabled` is a method to get user preferences specific to
  // your application, and not part of the Glean API.
  isTelemetryEnabled(),
  {
    httpClient: new MyCustomUploader()
  }
);

Glean.js pre-configured uploader

import { BrowserSendBeaconUploader } from '@mozilla/glean/web';


Glean.initialize(
  'my-app-id',
  isTelemetryEnabled(),
  {
    httpClient: BrowserSendBeaconUploader
  }
);

Further reading