| --- |
| id: OnlineManager |
| title: OnlineManager |
| --- |
| |
| The `OnlineManager` manages the online state within TanStack Query. It can be used to change the default event listeners or to manually change the online state. |
|
|
| > Per default, the `onlineManager` assumes an active network connection, and listens to the `online` and `offline` events on the `window` object to detect changes. |
|
|
| > In previous versions, `navigator.onLine` was used to determine the network status. However, it doesn't work well in Chromium based browsers. There are [a lot of issues](https://bugs.chromium.org/p/chromium/issues/list?q=navigator.online) around false negatives, which lead to Queries being wrongfully marked as `offline`. |
|
|
| > To circumvent this, we now always start with `online: true` and only listen to `online` and `offline` events to update the status. |
|
|
| > This should reduce the likelihood of false negatives, however, it might mean false positives for offline apps that load via serviceWorkers, which can work even without an internet connection. |
|
|
| Its available methods are: |
|
|
| - [`setEventListener`](#onlinemanagerseteventlistener) |
| - [`subscribe`](#onlinemanagersubscribe) |
| - [`setOnline`](#onlinemanagersetonline) |
| - [`isOnline`](#onlinemanagerisonline) |
|
|
| ## `onlineManager.setEventListener` |
|
|
| `setEventListener` can be used to set a custom event listener: |
|
|
| ```tsx |
| import NetInfo from '@react-native-community/netinfo' |
| import { onlineManager } from '@tanstack/react-query' |
| |
| onlineManager.setEventListener((setOnline) => { |
| return NetInfo.addEventListener((state) => { |
| setOnline(!!state.isConnected) |
| }) |
| }) |
| ``` |
|
|
| ## `onlineManager.subscribe` |
|
|
| `subscribe` can be used to subscribe to changes in the online state. It returns an unsubscribe function: |
|
|
| ```tsx |
| import { onlineManager } from '@tanstack/react-query' |
| |
| const unsubscribe = onlineManager.subscribe((isOnline) => { |
| console.log('isOnline', isOnline) |
| }) |
| ``` |
|
|
| ## `onlineManager.setOnline` |
|
|
| `setOnline` can be used to manually set the online state. |
|
|
| ```tsx |
| import { onlineManager } from '@tanstack/react-query' |
| |
| // Set to online |
| onlineManager.setOnline(true) |
| |
| // Set to offline |
| onlineManager.setOnline(false) |
| ``` |
|
|
| **Options** |
|
|
| - `online: boolean` |
|
|
| ## `onlineManager.isOnline` |
|
|
| `isOnline` can be used to get the current online state. |
|
|
| ```tsx |
| const isOnline = onlineManager.isOnline() |
| ``` |
|
|
