FetchAPITransport

A TrackerTransport based on Fetch API.

Customizing fetchFunction

FetchAPITransport supports overriding the parameters of the default Fetch function or the function itself.

In the following example we use the default fetch implementation and customize its parameters.

import { 
  defaultFetchFunction, 
  defaultFetchParameters, 
  FetchAPITransport 
} from '@objectiv/tracker-browser';

const COLLECTOR_ENDPOINT = 'https://collector.app.dev';

// Create a simple factory to make a custom FetchAPITransport with our customFetchParameters.  
const makeCustomFetchAPITransport = ({ endpoint: string }) => new FetchAPITransport({
  endpoint,
  fetchFunction: ({ endpoint, events }) => defaultFetchFunction({
    endpoint,
    events,
    // Pass our custom parameters to the defaultFetchFunction
    parameters: {
      ...defaultFetchParameters,
      mode: 'cors',
      cache: 'no-cache',
      headers: {
        'Content-Type': 'application/json',
      },
    }
  }),
});

// Create a custom Transport using our customFetchAPITransport
const customTransport = new TrackerTransportRetry({
  transport: new TrackerTransportSwitch({
    transports: [
      makeCustomFetchAPITransport({ endpoint: COLLECTOR_ENDPOINT }),
      new XMLHttpRequestTransport({ endpoint: COLLECTOR_ENDPOINT }),
    ],
  }),
})

// Now we can pass the custom Transport to makeTracker or a Browser Tracker instance
makeTracker({
  applicationId: 'test',
  transport: customTransport,
});

see also

• XMLHttpRequestTransport