webextensions-lib-dom-updater

A simple DOM Updater for browser extensions, aiming to help cross-process request to update DOM contents in a "server" extension. Designed mainly for the real DOM world on web browsers, not for Node.js world.

This includes a diff implementation ported from Python.

Usage

Put src/diff.js and src/dom-updater.js together into your extension. For example:

$ npm install webextensions-lib-dom-updater
$ cp node_modules/webextensions-lib-dom-updater/src/diff.js ../your-extension/src/
$ cp node_modules/webextensions-lib-dom-updater/src/dom-updater.js ../your-extension/src/

or

$ git clone https://github.com/piroor/webextensions-lib-dom-updater.git
$ cp webextensions-lib-dom-updater/src/diff.js ../your-extension/src/
$ cp webextensions-lib-dom-updater/src/dom-updater.js ../your-extension/src/

or

$ cd your-extension/src
$ wget https://github.com/piroor/webextensions-lib-dom-updater/raw/master/src/diff.js
$ wget https://github.com/piroor/webextensions-lib-dom-updater/raw/master/src/dom-updater.js

Then you can load the updater like:

import { DOMUpdater } from './dom-updater.js';
 
DOMUpdater.update(document.getElementById('target'), changes);

Usecase on browser extensions

On the client extension side:

const tab = await browser.tabs.get(tabId);
browser.runtime.sendMessage(
  'ID of the server extension',
  `
    <span id="tab"
          class="${tab.active ? 'active' : ''}">
      <span id="throbber"
            class="${tab.status}">
        <span id="throbber-image"
              class="${tab.status}"></span>
      </span>
      <img id="favicon"
           class="${tab.status}"
           src="${tab.favIconUrl}">
      <span id="label">${tab.title}</span>
    </span>
  `.trim()
);

On the server extension side:

browser.runtime.onMessageExternal(message => {
  const before = document.getElementById('tab-renderer');
 
  const range = document.createRange();
  range.setStart(document.body, 0);
  const after = range.createContextualFragment(message);
  range.detach();
 
  DOMUpdater.update(before, after);
});

How to run test

$ npm install
$ npm run test

License

• dom-updater.js and most resources are licensed under the MIT License.
• diff.js is licensed under the Python Software Foundation License.