Web/API/Fetchevent/request

The request read-only property of the FetchEvent interface returns the Request that triggered the event handler.

This property is non-nullable (since version 46, in the case of Firefox.) If a request is not provided by some other means, the constructor init object must contain a request (see FetchEvent.FetchEvent().)

Syntax

var recentRequest = fetchEvent.request;

Value

A Request object.

Example

This code snippet is from the service worker fetch sample (run the fetch sample live). The ServiceWorkerGlobalScope.onfetch event handler listens for the fetch event. When fired, pass a promise that back to the controlled page to FetchEvent.respondWith(). This promise resolves to the first matching URL request in the Cache object. If no match is found, the code fetches a response from the network.

The code also handles exceptions thrown from the ServiceWorkerGlobalScope.fetch operation. Note that an HTTP error response (e.g., 404) will not trigger an exception. It will return a normal response object that has the appropriate error code set.

self.addEventListener('fetch', function(event) {
  console.log('Handling fetch event for', event.request.url);

  event.respondWith(
    caches.match(event.request).then(function(response) {
      if (response) {
        console.log('Found response in cache:', response);

        return response;
      }
      console.log('No response found in cache. About to fetch from network...');

      return fetch(event.request).then(function(response) {
        console.log('Response from network is:', response);

        return response;
      }).catch(function(error) {
        console.error('Fetching failed:', error);

        throw error;
      });
    })
  );
});

Specifications

Specification	Status	Comment
Service WorkersThe definition of 'request' in that specification.	Working Draft	Initial definition.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`request` Experimental'	Chrome Full support Yes	Edge Full support ≤79	Firefox Full support 44	IE No support No	Opera Full support Yes	Safari No support No	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android ?	Opera Android Full support Yes	Safari iOS No support No	Samsung Internet Android Full support Yes

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown
Experimental. Expect behavior to change in the future.': Experimental. Expect behavior to change in the future.