Build Your Own Extension
Jyotsna Gupta
Mozilla Representative
Add-ons Content Reviewer
Former Featured Add-ons Advisory Board Member
Judge at Firefox Quantum Extension Challenge'18
@jyotsna17gupta| jyotsna17gupta.github.io |
jyotsna17gupta@gmail.com
- Browser Add-ons
- WebExtensions
- Anatomy of WebExtensions
- Extension API's
- Contribution opportunities
Agenda
Browser Add-ons extend and modify the functionality of the browser.
Browser Add-ons?
Firefox is the most customizable browser!
1 Million+ add-ons downloaded everyday
150million+ Add-ons used everyday
45+ percentage of users use at least one Add-on
WebExtensions
A cross-browser system for developing browser add-ons
- Uses standard HTML, CSS and JS
- e10s compatible (multiprocess)
- With Zero or Minimal changes, run it on Chrome, Edge and Opera
- Documentations from multiple resources.
Why WebExtensions?
Few WebExtension API's
Anatomy/Architecture of WebExtensions
manifest.json
{
"manifest_version": 2,
"name": "PrivateX",
"version": "2.0",
"description": "This add-on lets the user open websites with critical user information [Like banking, travel sites, etc] in a private window, without the hassle of copying the URL. In-case an URL doesn't work, mail us at jyotsna17gupta [AT] gmail [DOT] com.",
"homepage_url": "https://github.com/jyotsna17gupta/PrivateX",
// Addon Manager Icons
"icons": {
"16": "icons/unsafe-16.png",
"32": "icons/unsafe-32.png",
"48": "icons/unsafe-48.png",
"64": "icons/unsafe-64.png",
"128": "icons/unsafe-128.png"
},
"permissions": [
"activeTab",
"tabs"
],
"page_action": {
"browser_style": true,
"default_icon": {
"16": "icons/unsafe-16.png",
"32": "icons/unsafe-32.png",
"48": "icons/unsafe-48.png"
},
"default_title": "Click here for Private browsing!"
},
"background": {
"scripts": ["background.js"]
}
}Background scripts
-
Loaded as soon as the extension is loaded
-
Stay loaded until the extension is disabled or uninstalled
-
You can use any of the WebExtension APIs in the script
"background": {
"scripts": ["background-script.js"]
}Content Scripts
-
Similar to loading normal scripts in the page
-
Can access DOM structure and use a small subset of the WebExtension APIs
-
Make cross-domain XHR requests
-
Exchange messages with their background scripts and can in this way indirectly access all the WebExtension APIs
"content_scripts": [
{
"matches": ["*://*.mozilla.org/*"],
"js": ["jquery.js", "content-script.js"]
}
]Browser action
- Used to add button to browser toolbar
- Use this when your add-on's features are applicable to all websites else use Page action instead.
"browser_action": {
"default_icon": {
"19": "button/geo-19.png",
"38": "button/geo-38.png"
},
"default_title": "Whereami?",
"default_popup": "popup/choose_beast.html"
}browser.browserAction.onClicked.addListener(handleClick);Page action
- Used to add button to address toolbar
- Use this when your add-on's features are specific to a particular website.
"page_action": {
"default_icon": {
"19": "button/geo-19.png",
"38": "button/geo-38.png"
},
"default_title": "Whereami?",
"default_popup": "popup/choose_beast.html"
}browser.pageAction.onClicked.addListener(handleClick);WebExtension API's
Notifications API
browser.notifications.create(cakeNotification, {
"type": "basic",
"iconUrl": browser.extension.getURL("icons/cake-96.png"),
"title": "Time for cake!",
"message": "Something something cake"
});Tabs API
function onCreated(tab) {
console.log(`Created new tab: ${tab.id}`)
}
function onError(error) {
console.log(`Error: ${error}`);
}
browser.browserAction.onClicked.addListener(function() {
var creating = browser.tabs.create({
url:"https://example.org"
});
creating.then(onCreated, onError);
});Alarms API
const delayInMinutes = 5;
browser.alarms.create({
delayInMinutes
});function onCreated(windowInfo) {
console.log(`Created window: ${windowInfo.id}`);
}
function onError(error) {
console.log(`Error: ${error}`);
}
browser.browserAction.onClicked.addListener((tab) => {
var creating = browser.windows.create({
url: ["https://developer.mozilla.org",
"https://addons.mozilla.org"]
});
creating.then(onCreated, onError);
});Windows API
webRequest API
- cancel the request in:
- redirect the request in:
Sequence of events
var target = "https://developer.mozilla.org/*";
/*
e.g.
"https://developer.mozilla.org/en-US/"
200
or:
"https://developer.mozilla.org/en-US/xfgkdkjdfhs"
404
*/
function logResponse(responseDetails) {
console.log(responseDetails.url);
console.log(responseDetails.statusCode);
}
browser.webRequest.onCompleted.addListener(
logResponse,
{urls: [target]}
);Example:
web-ext CLI
A command line tool to help build, run, and test WebExtensions.
npm install --global web-ext
Few Commands
use --help on the command line, such as web-ext build --help
Debugging your add-on
Publishing your Add-on
Contribution Opportunities
You can be a content reviewer!
or an Addon Reviewer!
Code Contribution!
AMO(add-ons frontend and server)
Themes in Firefox!
Don't know what to make?
Need a few ideas??
Here you go!!!
http://bit.ly/addons-ideas
Links:
Need help?
IRC Channels: #webextensions, #extdev, #addons
Mailing List: https://mail.mozilla.org/listinfo/dev-addons
Telegram: @addonschat
Questions?
Jyotsna Gupta | @jyotsna17gupta | jyotsna17gupta@gmail.com
Slides: https://slides.com/jenal/fx-addons/
Cross Browser Add-ons
By Jyotsna Gupta
Cross Browser Add-ons
Build Your Own Extension
