Web Application Addon

Web Application addons are software programs that run on the Web applications. They work as part of each Web application. You can use addons to add or customize the Web application behavior according to your needs or preferences in all commonly installed Web applications. Web technologies such as HTML, JavaScript, and CSS are used to build them.

Figure: Addon Concept

Addon concept


This feature is supported from Tizen version 5.5.

The main features of the service application include:

  • Configuration

    You must have a manifest file and a main JavaScript file.

  • Event

    You can use several events from a Web application to get the timing to perform what you want using addon on the Web application.

  • Mechanism

    You can understand how each addon works.

  • Comparing to Chrome Extensions

    Addons look similar to Chrome Extensions. However, there are certain differences that you can understand in this section.

  • API

    To write addons, you can use the predefined set of APIs.

  • Packaging

    To generate a package for an addon, you can use Tizen Studio. There is a separate tag for addon in config.xml.

  • Management

    To manage installed addons, you can use a separate Web application named Web App Addon Setting.


Manifest file

You must have a manifest file.

The manifest file includes the metadata for an addon:

  • name: Name of the addon.
  • version: Version of the addon.
  • main: Name of the main JavaScript.
  • settings: Null (This is for future functionality)
  • description: Description of the addon.

Following is an example of a manifest file. The filename must be manifest.json:

    “name”: “addonSampleAd”,
    "version”: “0.0.1”,
    “main”: “addonSampleAd”,
    “settings”: “”,
    “description”: “Sample to show how to show up advertisement at prelaunch event”

Main JavaScript file

You must have a main JavaScript file.

The main JavaScript file must have the same name as main in the manifest file. The main JavaScript file includes:

  • activate(): To register a callback to an addon event.
  • deactivate(): To unregister the callback to an addon event.
  • Callback Functions: You can write your own code to define the behavior that happens when an addon event occurs.

Following is an example of a main JavaScript file:

class AddonSampleAd {
    constructor(em) {
      console.log('AddonSampleAd constructor');
      this.evt = em;
    activate() {
        this.evt.on('lcPrelaunch', this.prelaunch);
    deactivate() {
        this.evt.off('lcPrelaunch', this.prelaunch);
    prelaunch(winId, orgUrl) {
module.exports = AddonSampleAd;


Event Description
lcPrelaunch Emitted once for Web app launching just before the main page is shown.
lcResume Emitted when the app is resumed.
lcSuspend Emitted when the app is suspended.
lcQuit Emitted before the app is closed.
contentDidFinishLoad Emitted when the page navigation is done.


Addons are not standalone software programs, and only run when a Web application runs. They work on event-driven invocation. Each addon registers its callbacks to events that are pre-defined in Web Runtime JS (WRTjs). Registered callbacks are invoked whenever the registered events occur during the Web application’s life cycle.

Figure: Addon Mechanism

Addon mechanism

Comparing to Chrome Extensions

Following are the differences from Chrome Extensions:

  1. Applying to Multiple Applications

    Chrome Extensions are applied to multiple tabs in an application named Chrome browser. However, addons are applied to multiple Web applications in a platform such as Tizen.

  2. Wide Range of Customization

    Addons can customize an action when each Web application’s life cycle event such as Prelaunch, Resume, Suspend, or Quit occurs. Addons get the notification after they register their own callback for a lifecycle event. That is possible because they run on WRTjs, also known as Web Runtime JS, which manages and controls from birth to death of Web applications.


Addon APIs are provided to support the way to handle the window in both the browser process and the renderer process. More APIs will be added in future. The renderer process here is only available when the addon itself has HTML files and they are loaded.

Table: Supported APIs

Module API Description Type
window loadURL
They provide core operation for window manipulation. Browser
messaging onMessage

They provide a way to communicate between the browser process and the renderer process.
Renderer is not the one of Web application but the one for the addon’s own page.



To generate a package for an addon, you can use Tizen Studio.

The characteristics of the addon packages include:

  • Extension: WGT
  • Icon after installation: Not Shown
  • Tag in config file: <tizen:addon>

Following is an example of the config.xml file:

<?xml version="1.0" encoding="UTF-8"?>
<widget xmlns:tizen="http://tizen.org/ns/widgets" xmlns="http://www.w3.org/ns/widgets" id="http://yourdomain/AddonSampleAd" version="1.0.0" viewmodes="maximized">
    <tizen:addon package="TFh8kl6ztm" required_version="5.5"/>
    <tizen:profile name="mobile"/>

<tizen:addon> is a child element of the <widget> tag. You can set traits of an addon such as package id and required version. For required version, you must set it as 4.0 or higher. However, it is recommended to use 5.5 as addons are supported from Tizen version 5.5.


<tizen:application> is removed. It is replaced with <tizen:addon> in addon packaging.

Location of Addon files

You must put the addon related files in the following directory:

{project root}/shared/res

If you put the addon related files in some other location then the addons will not be recognized.

Manage addons

Web App Addon Setting is pre-installed in the Tizen platform binary. It provides the following functionalities:

  • List Up: It shows up all the installed addons.
  • Activation(On): You can activate each installed addon by clicking On.
  • Deactivation(Off): You can deactivate each installed addon by clicking Off.
  • Uninstallation: You can uninstall each installed addon by clicking X.

Figure: Addon Setting App

Addon Setting App

  • Dependencies
    • Tizen 5.5 and Higher for Mobile
    • Tizen 5.5 and Higher for Wearable