WebBrowser.coolDownAsync(browserPackage)

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.

• Promise<WebBrowserCoolDownResult>

The promise which fulfils with WebBrowserCoolDownResult when cooling is performed, or an empty object when there was no connection to be dismissed.

WebBrowser.dismissAuthSession()

• void

WebBrowser.dismissBrowser()

Dismisses the presented web browser.

• void

The void on successful attempt, or throws error, if dismiss functionality is not avaiable.

WebBrowser.getCustomTabsSupportingBrowsersAsync()

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 default.)

• Promise<WebBrowserCustomTabsResults>

The promise which fulfils with WebBrowserCustomTabsResults object.

WebBrowser.mayInitWithUrlAsync(url, browserPackage)

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

• Promise<WebBrowserMayInitWithUrlResult>

A promise which fulfils with WebBrowserMayInitWithUrlResult object.

WebBrowser.maybeCompleteAuthSession(options)

Possibly completes an authentication session on web in a window popup. The method should be invoked on the page that the window redirects to.

• WebBrowserCompleteAuthSessionResult

Returns an object with message about why the redirect failed or succeeded:

If type is set to failed, the reason depends on the message:

• Not supported on this platform: If the platform doesn't support this method (iOS, Android).
• Cannot use expo-web-browser in a non-browser environment: If the code was executed in an SSR or node environment.
• No auth session is currently in progress: (the cached state wasn't found in local storage). This can happen if the window redirects to an origin (website) that is different to the initial website origin. If this happens in development, it may be because the auth started on localhost and finished on your computer port (Ex: 128.0.0.*). This is controlled by the redirectUrl and returnUrl.
• Current URL "<URL>" and original redirect URL "<URL>" do not match: This can occur when the redirect URL doesn't match what was initial defined as the returnUrl. You can skip this test in development by passing { skipRedirectCheck: true } to the function.

If type is set to success, the parent window will attempt to close the child window immediately.

If the error ERR_WEB_BROWSER_REDIRECT was thrown, it may mean that the parent window was reloaded before the auth was completed. In this case you'll need to close the child window manually.

WebBrowser.openAuthSessionAsync(url, redirectUrl, options)

On iOS:

Opens the url with Safari in a modal using ASWebAuthenticationSession. The user will be asked whether to allow the app to authenticate using the given url.

On Android:

This will be done using a "custom Chrome tabs" browser, AppState, and Linking APIs.

On web:

This API can only be used in a secure environment (https). You can use expo start:web --https

to test this. Otherwise, an error with code ERR_WEB_BROWSER_CRYPTO will be thrown. This will use the browser's window.open() API.

• Desktop: This will create a new web popup window in the browser that can be closed later using WebBrowser.maybeCompleteAuthSession().
• Mobile: This will open a new tab in the browser which can be closed using WebBrowser.maybeCompleteAuthSession().

How this works on web:

• A crypto state will be created for verifying the redirect.
  • This means you need to run with expo start:web --https
• The state will be added to the window's localstorage. This ensures that auth cannot complete unless it's done from a page running with the same origin as it was started. Ex: if openAuthSessionAsync is invoked on https://localhost:19006, then maybeCompleteAuthSession must be invoked on a page hosted from the origin https://localhost:19006. Using a different website, or even a different host like https://128.0.0.*:19006 for example will not work.
• A timer will be started to check for every 1000 milliseconds (1 second) to detect if the window has been closed by the user. If this happens then a promise will resolve with { type: 'dismiss' }.

On mobile web, Chrome and Safari will block any call to window.open()

which takes too long to fire after a user interaction. This method must be invoked immediately after a user interaction. If the event is blocked, an error with code ERR_WEB_BROWSER_BLOCKED will be thrown.

• Promise<WebBrowserAuthSessionResult>

• If the user does not permit the application to authenticate with the given url, the Promise fulfills with { type: 'cancel' } object.
• If the user closed the web browser, the Promise fulfills with { type: 'cancel' } object.
• If the browser is closed using dismissBrowser, the Promise fulfills with { type: 'dismiss' } object.

WebBrowser.openBrowserAsync(url, browserParams)

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.

• Promise<WebBrowserResult>

The promise behaves differently based on the platform. 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' }.

WebBrowser.warmUpAsync(browserPackage)

This method calls warmUp method on CustomTabsClient for specified package.

• Promise<WebBrowserWarmUpResult>

A promise which fulfils with WebBrowserWarmUpResult object.