Expo

Documentation

WebBrowser

Provides access to the system's web browser and supports handling redirects. On iOS, it uses SFSafariViewController or SFAuthenticationSession, depending on the method you call, and on Android it uses ChromeCustomTabs. As of iOS 11, SFSafariViewController no longer shares cookies with the Safari, so if you are using WebBrowser for authentication you will want to use WebBrowser.openAuthSessionAsync, and if you just want to open a webpage (such as your app privacy policy), then use WebBrowser.openBrowserAsync.

Platform Compatibility

Android DeviceAndroid EmulatoriOS DeviceiOS SimulatorWeb

For managed apps, you'll need to run expo install expo-web-browser. To use it in a bare React Native app, follow its installation instructions.

import React, { Component } from 'react';
import { Button, Text, View } from 'react-native';
import * as WebBrowser from 'expo-web-browser';

export default class App extends Component {
  state = {
    result: null,
  };

  render() {
    return (
      <View>
        <Button title="Open WebBrowser" onPress={this._handlePressButtonAsync} />
        <Text>{this.state.result && JSON.stringify(this.state.result)}</Text>
      </View>
    );
  }

  _handlePressButtonAsync = async () => {
    let result = await WebBrowser.openBrowserAsync('https://expo.io');
    this.setState({ result });
  };
}

If you are using the WebBrowser window for authentication or another use case where you would like to pass information back into your app through a deep link, be sure to add a handler with Linking.addEventListener before opening the browser. When the listener fires, you should call dismissBrowser -- it will not automatically dismiss when a deep link is handled. Aside from that, redirects from WebBrowser work the same as other deep links. Read more about it in the Linking guide.

import * as WebBrowser from 'expo-web-browser';

Opens the url with Safari in a modal on iOS using SFSafariViewController, and Chrome in a new custom tab on Android. On iOS, the modal Safari will not share cookies with the system Safari. If you need this, use openAuthSessionAsync.

Arguments

  • url (string) -- The url to open in the web browser.
  • options (object) (optional) -- A dictionaty with following key-value pairs:
    • toolbarColor (optional) (string) -- color of the toolbar in either #AARRGGBB or #RRGGBB format.
    • enableBarCollapsing (optional) (boolean) -- a boolean determining whether the toolbar should be hiding when a user scrolls the website
    • controlsColor (optional) (string) -- (iOS only) tint color for controls in SKSafariViewController in #AARRGGBB or #RRGGBB format.
    • showTitle (optional) (boolean) -- (Android only) a boolean determining whether the browser should show the title of website on the toolbar
    • package (optional) (string) -- (Android only). Package name of a browser to be used to handle Custom Tabs. List of available packages is to be queried by getCustomTabsSupportingBrowsers method.
    Note that behavior customization options depend on the actual browser and its version. Some or all of the arguments may be ignored.

Returns

The promise behaves differently on iOS and Android.
On Android promise resolves with {type: 'opened'} if we were able to open browser.
On iOS:
  • If the user closed the web browser, the Promise resolves with { type: 'cancel' }.
  • If the browser is closed using dismissBrowser , the Promise resolves with { type: 'dismiss' }.

Opens the url with Safari in a modal on iOS using SFAuthenticationSession. The user will be asked whether to allow the app to authenticate using the given url. Unavailable on Android.

Arguments

  • url (string) -- The url to open in the web browser. This should be a login page.
  • redirectUrl (string) -- optional: the url to deep link back into your app. By default, this will be Constants.linkingUrl
Returns a Promise:
  • If the user does not permit the application to authenticate with the given url, the Promise resolved with { type: 'cancel' }.
  • If the user closed the web browser, the Promise resolves with { type: 'cancel' }.
  • If the browser is closed using dismissBrowser, the Promise resolves with { type: 'dismiss' }.

Android only
This method calls warmUp method on CustomTabsClient for specified package.

Arguments

  • browserPackage (string) -- optional -- package of browser to be warmed up. If not set, preferred browser will be warmed.

Returns

A promise resolving with { package: string }

Android only
This method initiates (if needed) CustomTabsSession and calls its mayLaunchUrl method for browser specified by the package.

Arguments

  • url (string) -- url of page that is likely to be loaded firts when opening browser
  • package (string) -- optional -- package of browser to be informed. If not set, preferred browser will be used.

Returns

The promise resolves with { package: string }.

Android only
This methods removes all bindings to services created by warmUpAsync or mayInitWithUrlAsync. You should call this method once you don't need them to avoid potential memory leaks. However, those binding would be cleared once your application is destroyed, which might be sufficient in most cases.

Arguments

  • browserPackage (string) -- optional -- package of browser to be cooled. If not set, preferred browser will be used.

Returns

The promise resolves with { package: string } when cooling is performed, or an empty object when there was no connection to be dismissed.

iOS only
Dismisses the presented web browser.

Returns

The promise resolves with { type: 'dismiss' }.

Android only
Returns a list of applications package names supporting Custom Tabs, Custom Tabs service, user chosen and preferred one. This may not be fully reliable, since it uses PackageManager.getResolvingActivities under the hood. (For example, some browsers might not be present in browserPackages list once another browser is set to defult.)

Returns

The promise resolves with { browserPackages: string[], defaultBrowserPackage: string, servicePackages: string[], preferredBrowserPackage: string }
  • browserPackages (string[]) : All packages recognized by PackageManager as capable of handling Custom Tabs. Empty array means there is no supporting browsers on device.
  • defaultBrowserPackage (string | null) : Default package chosen by user. Null if there is no such packages. Null usually means, that user will be prompted to choose from available packages.
  • servicePackages (string[]) : All packages recognized by PackageManager as capable of handling Custom Tabs Service. This service is used by warmUpAsync, mayInitWithUrlAsync and coolDownAsync.
  • preferredBrowserPackage (string | null) : Package preferred by CustomTabsClient to be used to handle Custom Tabs. It favors browser chosen by user as default, as long as it is present on both browserPackages and servicePackages lists. Only such browsers are considered as fully supporting Custom Tabs. It might be null when there is no such browser installed or when default browser is not in servicePackages list.
In general, services are used to perform background tasks. If a browser is available in servicePackage list, it should be capable of performing warmUpAsync, mayInitWithUrlAsync and coolDownAsync. For opening an actual web page, browser must be in browserPackages list. A browser has to be present in both lists to be considered as fully supporting Custom Tabs.