A handy wrapper for the Background Sync API
Made with ❤ at @outlandish
Fetch Sync allows you to proxy fetch requests through the Background Sync API using a simple fetch-like API.
Check out a live demo here.
npm install fetch-sync --save
- Requirements
- Support
- Features
- Initialisation
- Usage
- Sync API
- Todo
- Test
- Development
- Contributing
- Author & License
The library utilises some new technologies so currently only works in some browsers. It definitely works in
Chrome Canary
with the experimental-web-platform-features
flag enabled.
The browser must support:
- Background Sync
- Service Worker
- Fetch
- IndexedDB
- [Promise] (https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Promise)
Chrome Canary | Chrome | Firefox | IE | Opera | Safari |
---|---|---|---|---|---|
✔ | ✘ | ✘ | ✘ | ✘ | ✘ |
-
Register a Background Sync operation with one call to
fetchSync()
. -
Shares exactly the same API as
fetch
. Accepts a Request or String, and returns the Promise of a Response. -
Manage sync operations with
fetchSync.{get,getAll,cancel,cancelAll}()
. -
Named sync operations have their response stored within an IndexedDB store.
Existing Service Worker
If your application already uses a Service Worker, you can import the Fetch Sync worker using importScripts
:
importScripts('node_modules/fetch-sync/dist/fetch-sync.sw.min.js')
And then call fetchSync.init()
somewhere in your application's initialisation procedure.
No Service Worker
Fetch Sync can handle registration if you don't use a SW already...
Either serve the Fetch Sync worker file with a header "Service-Worker-Allowed : /"
, or to avoid configuring headers,
create a Service Worker script in the root of your project and use the method above for 'Existing Service Worker'.
Then see the example under Usage for the fetchSync.init()
method.
Initialise fetchSync.
-
options {Object} (optional) options object
options { // The URL of the fetchSync worker script. workerUrl {String} (required, default: null) // The options object to pass to the worker registration function. workerOptions {Object} (optional, default: null) // Force the worker registration to update the worker script. forceUpdate {Boolean} (optional, default: false) }
Example:
// Import client lib...
// ES6
import fetchSync from 'fetch-sync'
// ES5
var fetchSync = require('fetch-sync')
// Script, using bundled dist
<script src="/node_modules/fetch-sync/dist/fetch-sync.min.js"></script>
// Initialise, passing in worker lib location...
fetchSync.init({
workerUrl: 'node_modules/fetch-sync/dist/fetch-sync.sw.js',
workerOptions: {
scope: '<website address>' // e.g. 'http://localhost:8000'
}
})
Perform a sync
Background Sync operation.
- [name] {String} (optional) name of the sync operation
- request {String|Request} URL or an instance of fetch Request
- [options] {Object} (optional) fetch options object
Returns a Promise that resolves on success of the fetch request.
If called with a name
the response will be stored and can be retrieved later using fetchSync.get(<name>)
and then
sync.getResponse()
. See the Sync API for more details.
Examples:
-
named GET
fetchSync('GetMessages', '/messages')
-
unnamed POST
fetchSync('/update-profile', { method: 'POST', body: { name: '' } })
-
named with options
fetchSync('/send-message', { body: 'Hello!' })
-
unnamed with Request
fetchSync( new Request('/messages') )
Get a sync by its name.
See the Sync API docs for available properties/methods.
- name {String} name of the sync operation to get
Get all sync operations.
Returns an array of all sync operations (named and unnamed).
Cancel the sync with the given name
.
- name {String} name of the sync operation to cancel
Cancel all syncs, named and unnamed.
Cancels the sync operation.
Returns a Promise of success of the cancellation.
Response retrieved when the operation was completed. Or null if the operation is incomplete.
The unique ID of the sync operation. This will be its name if it has one.
The name of the sync operation if it has one.
The time that the sync operation was created.
The time that the sync operation was completed.
Useful for named syncs that you want to retrieve later on.
- [WIP] Add support for periodicSync operations.
(See the outdated
periodic-sync-support
branch.) - Reduce size of client and SW bundles.
As the library depends on Service Workers and no headless browser has (good enough) support for Service Workers that would allow tests to be executed within the console, tests are ran through the browser using Mocha and Chai.
On running npm test
an Express server will be started at localhost:8000
.
Run the tests:
$ cd fetch-sync
$ npm test
The library is bundled by Webpack and transpiled by Babel.
- Install dependencies:
npm install
- Start Webpack in a console:
npm run watch
- Start the test server in another:
npm test
- Navigate to
http://localhost:8000
All pull requests and issues welcome!
If you're not sure how, check out Kent C. Dodds' great video tutorials on egghead.io!
fetch-sync
was created by Sam Gluck and is released under the MIT license.