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 Workers The definition of 'request' in that specification. |
Working Draft | Initial definition. |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
request | 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.