JavaScript Calls

This page lists the JavaScript calls that are available through the Screenleap API. To integrate, add the following snippet of code to the page that will be used to start the share session right before the closing body tag.

• Start a Share Session
• Controlling an Active Share Session
• Implementing Callback Functions
• Access Share Session Properties
• Installing the Browser Extension

Start a Share Session

After you have created a share session (see Make a Share Session Request), these functions can be used to start the share session.

screenleap.startSharing(presenterAppType, screenShareData, callbacks)

Starts a share session using the specified presenter app.

The available presenterAppType options are:

• IFREE - Installation-free sharing. Neither the presenters nor viewers need to install any software.
• NATIVE - The native Screenleap application for Mac and Windows. The native application has the advantage of only requiring a download the first time it is run, or when an update is required.

The screenShareData is the JSON object received from a successful request to make a new share session.

The callbacks is a JavaScript object contain functions that you implement that will be called when specific share session events occur during the course of a share session. The available callbacks are:

• nativeDownloadStarting - For NATIVE shares, this callback will be called when the download of the native app begins. Use this callback to show instructions to the users for installing the app and starting the share session.
• screenShareStarting - For all shares, this callback will be called when the downloaded app starts. Use it to display feedback to the user that the share is starting.
• screenShareStartError - This callback will be called when the share session cannot be started. Use this callback to let the user know that the share session was unable to be started and allow them to try starting a new share.

screenleap.downloadNativeApp(onAppDownloadEnd, callbacks)

Downloads the native app and calls the onAppDownloadEnd function when the download is complete.

Accepted callback:

• nativeDownloadStarting: function to call before the download begins. Use this call to display the installation instructions.

screenleap.startAppUsingCustomProtocolHandler()

Attempts to start the native app using the custom protocol handler. This call is usually made from a link in the instructions shown the users when the automatic attempt to start the presenter app using the custom protocol handler fails.

Controlling an Active Share Session

• screenleap.stopSharing() - Stop the active share session.
• screenleap.pauseSharing(successCallback, errorCallback) - Pause the active share session.
• screenleap.resumeSharing(successCallback, errorCallback) - Resume a paused but active share session.

ImplementingCallback Functions

You can get notified about various screen sharing events by implementing JavaScript callback functions on the screenleap object. For example, you can get notified when a viewer joins or leaves a share session so that you can update your page to show or hide participant information.

screenleap.onScreenShareStart()

This function is called when the web page is able to successfully connect to the presenter app. If you do not define this function, the default behavior is to pop up an alert.

screenleap.onPresenterConnect()

This function is called when the presenter app has successfully connected to the app server. screenleap.onPresenterConnect usually gets called after screenleap.onScreenShareStart but this is not guaranteed. Most of the time, you can implement either callbacks to add code you want to run after the share session starts. Some Screenleap JavaScript calls (such as screenleap.startRecording and screenleap.stopRecording) only works after the presenter app has connected to the app server, so you'll want to use the screenleap.onPresenterConnect callback for these situations.

screenleap.onScreenShareEnd()

This function is called when a share session ends. If you do not define this function, the default behavior is to pop up an alert.

screenleap.onViewerConnect(participantId, externalId)
screenleap.onViewerDisconnect(participantId, externalId)

These functions are called whenever a viewer joins or leaves a share session, respectively. The participantId is a Screenleap identifier for a participant. The externalId parameter will only be included if you provided an optional externalId for this viewer's connection.

Note that this information is provided in order to give the presenter real-time information about viewer presence. It is not intended to be used for billing purposes. If a viewer's Internet connection drops and reconnects repeatedly, each event will trigger a callback. Please make use of the callbackOnEndUrl callback to receive billing information for a completed share session.

screenleap.onPause()
screenleap.onResume()

These functions will get called when the share session gets paused or resumed, respectively.

screenleap.showMicrophoneButton()

This function will get called when audio conferencing is enabled to display the button used to toggle muting/un-muting of the user's microphone.

screenleap.hideMicrophoneButton()

This function will get called when audio conferencing is disabled to hide the button used to toggle muting/un-muting of the user's microphone.

screenleap.onRecordStartError

This function is called when we are unable to start recording the share session due to an error. When calling screenleap.startRecording, if errorCallback is passed in, errors starting the recording will be passed to the callback. Otherwise, errors starting the recording will be reported via screenleap.onRecordStartError. Even if you pass errorCallback to screenleap.startRecording, you should still implement screenleap.onRecordStartError so you get notified when recording couldn't be started when autoRecord is enabled.

screenleap.error(action, message, err)

This function is called when an error is encountered. The action is the name of the action that triggered the error. The message may provide some additional explanation of the issue. The err is either an Error object or an XmlHttpRequest object, depending on the type of error. The default behavior is to pop up an alert to help with integration. You will want to override this before releasing to your users so that your users are not shown an alert everytime there is an error.

Important Note: These functions are defined on the screenleap object which is instantiated by screenleap.js. As a result, it is important that you implement these callbacks in window.onload to ensure that the screenleap object is instantiated first.

Sample Callback Implementation

Access Share Session Properties

• screenleap.getScreenShareCode() - returns the 9-digit share code for this share session.
• screenleap.getViewerUrl() - returns the URL for viewing this share.

Installing the Browser Extension

• screenleap.isBrowserSupportedForExtension() - Returns true if the user's browser is supported for Screenleap browser extensions.
• screenleap.checkIsExtensionInstalled(yesCallback, noCallback) - Checks whether the Screenleap browser extension is installed, then calls the appropriate callback function.
• screenleap.checkIsExtensionEnabled(yesCallback, noCallback) - For Chrome only, checks whether the extension is enabled, then calls the appropriate callback function.
• screenleap.installExtension(successCallback, errorCallback, redirectUrl) - Installs the Screenleap extension, if it is not already installed, then calls the appropriate callback function. The Chrome installation will require a temporary redirect to a screenleap.com page. By default, the page is automatically redirected back to the originating URL on completion of the installation. To override this behavior, you may provide an alternate redirectUrl to which the user will be redirected after the installation completes.