react-native-sync-adapter

 

Intelligent Job-Scheduling port to React Native: Scheduling data background synchronizations that run in your JavaScript.

Read a broader introduction in the following post: React Native and Native Modules: The Android SyncAdapter

Requirements

* React Native 0.60+

Pros

Under the hood, this library uses a SyncAdapter:

* Android will trigger a sync using our syncFlexTime to decide when is the best moment to do so (battery efficiency)
* No need to worry about internet connection
* No need to worry about the user restarting the device
* Compatible with all Android versions supported by RN (4.1+)

Caveats

This library is only for Android. If you want to do something similar on iOS, I recommend using react-native-background-fetch.

Getting started

``
yarn add react-native-sync-adapter
`

$3

The library will be linked automatically by Autolinking.
However, this library requires some manual steps:

#### Manual Android required step
Open up the string.xml file of your Android project. You need to add the following (just change the content):
`xml
YourAppName
your.android.package.name
your.android.package.name.provider
`

This will override the default values from the library and make them unique for your app.

Usage


You need to register a task with a specific name and only with this specific name: TASK_SYNC_ADAPTER. You should do it in the same place where you register your app:

`js
AppRegistry.registerComponent('MyApp', () => MyApp);
AppRegistry.registerHeadlessTask('TASK_SYNC_ADAPTER', () => TestTask);
`

Then, for example, on your root component:
`js
import {useEffect} from 'react';
import SyncAdapter from 'react-native-sync-adapter';

useEffect(() => {
SyncAdapter.init({
syncInterval,
syncFlexTime,
});
}, []);
`

That is all! Some extras:

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The default timeout for your Headless JS task is 5 minutes (300000ms). If you want to override this value, you will also need to override strings.xml again:

`xml

600000
`

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By default the user will not be able to manually enable/disable syncs through the Account settings. If you want the user to have this option, you need to override strings.xml:

`xml

true
`

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By default, the sync task will only run if the app is not in the foreground. This is one of the default caveats from HeadlessJS.
If you want to override this behavior, you can, one more time overriding strings.xml:

`xml
true
`

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If you want to trigger a sync natively (e.g. responding to a broadcast receiver), you can call:

`java
SyncAdapter.syncImmediately(Context context, int syncInterval, int syncFlexTime);
`

API

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Schedules background syncs within your app.

`js
Object: {
syncInterval: number;
syncFlexTime: number;
}
`

* syncInterval: The amount of time in seconds that you wish to elapse between periodic syncs
* syncFlexTime: The amount of flex time in seconds before syncInterval that you permit for the sync to take place. Must be less than syncInterval

A good example could be syncInterval: 12 60 60 (12 hours) and syncFlexTime: 0.5 60 60 (30 minutes).

Notice that syncFlexTime only works for Android 4.4+, for older versions, that value will be ignored and syncs will be always exact.

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Invoke the sync task. Use the same values as in the init call.

`js
Object: {
syncInterval: number;
syncFlexTime: number;
}
`

Be aware that for this method to work (if you call it from inside your app) you need to allow the task to work on the foreground.

Running example

You can try this library running the example app:

`
cd example && yarn && npm start
`

Then just run:

`
yarn android
`

Be careful: The installed example app will trigger a sync around every minute (so it is easy to see that is working). If you debug the app, you should be able to see the HeadlessJS ouputing: Headless JS task was fired!` (remember not to have the app on the foreground: Unless you override this behavior). After you try it, I recommend to uninstall the app so you don't harm your device battery life.