react-native/Libraries/Network/NetInfo.js

144 lines
3.6 KiB
JavaScript

/**
* Copyright 2004-present Facebook. All Rights Reserved.
*
* @providesModule NetInfo
* @flow
*/
'use strict';
var NativeModules = require('NativeModules');
var RCTDeviceEventEmitter = require('RCTDeviceEventEmitter');
var RCTReachability = NativeModules.Reachability;
var DEVICE_REACHABILITY_EVENT = 'reachabilityDidChange';
type ChangeEventName = $Enum<{
change: string;
}>;
/**
* NetInfo exposes info about online/offline status
*
* == iOS Reachability
*
* Asyncronously determine if the device is online and on a cellular network.
*
* - "none" - device is offline
* - "wifi" - device is online and connected via wifi, or is the iOS simulator
* - "cell" - device is connected via Edge, 3G, WiMax, or LTE
* - "unknown" - error case and the network status is unknown
*
* ```
* NetInfo.reachabilityIOS.fetch().done((reach) => {
* console.log('Initial: ' + reach);
* });
* function handleFirstReachabilityChange(reach) {
* console.log('First change: ' + reach);
* NetInfo.reachabilityIOS.removeEventListener(
* 'change',
* handleFirstReachabilityChange
* );
* }
* NetInfo.reachabilityIOS.addEventListener(
* 'change',
* handleFirstReachabilityChange
* );
* ```
*/
var NetInfo = {};
if (RCTReachability) {
var _reachabilitySubscriptions = {};
NetInfo.reachabilityIOS = {
addEventListener: function (
eventName: ChangeEventName,
handler: Function
): void {
_reachabilitySubscriptions[handler] = RCTDeviceEventEmitter.addListener(
DEVICE_REACHABILITY_EVENT,
(appStateData) => {
handler(appStateData.network_reachability);
}
);
},
removeEventListener: function(
eventName: ChangeEventName,
handler: Function
): void {
if (!_reachabilitySubscriptions[handler]) {
return;
}
_reachabilitySubscriptions[handler].remove();
_reachabilitySubscriptions[handler] = null;
},
fetch: function(): Promise {
return new Promise((resolve, reject) => {
RCTReachability.getCurrentReachability(
(resp) => {
resolve(resp.network_reachability);
},
reject
);
});
},
};
/**
*
* == NetInfo.isConnected
*
* Available on all platforms. Asyncronously fetch a boolean to determine
* internet connectivity.
*
* ```
* NetInfo.isConnected.fetch().done((isConnected) => {
* console.log('First, is ' + (isConnected ? 'online' : 'offline'));
* });
* function handleFirstConnectivityChange(isConnected) {
* console.log('Then, is ' + (isConnected ? 'online' : 'offline'));
* NetInfo.isConnected.removeEventListener(
* 'change',
* handleFirstConnectivityChange
* );
* }
* NetInfo.isConnected.addEventListener(
* 'change',
* handleFirstConnectivityChange
* );
* ```
*
*/
var _isConnectedSubscriptions = {};
NetInfo.isConnected = {
addEventListener: function (
eventName: ChangeEventName,
handler: Function
): void {
_isConnectedSubscriptions[handler] = (reachability) => {
handler(reachability !== 'none');
};
NetInfo.reachabilityIOS.addEventListener(eventName, _isConnectedSubscriptions[handler]);
},
removeEventListener: function(
eventName: ChangeEventName,
handler: Function
): void {
NetInfo.reachabilityIOS.removeEventListener(eventName, _isConnectedSubscriptions[handler]);
},
fetch: function(): Promise {
return NetInfo.reachabilityIOS.fetch().then(
(reachability) => reachability !== 'none'
);
},
};
}
module.exports = NetInfo;