Web/API/Fetchevent/request

From Get docs


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.


See also