Userscript: Twitter Media Download

userscriptTwitterMediaDownload.js

// ==UserScript==
// @name         Twitter Video Download
// @namespace    http://scambier.github.io/
// @version      0.1
// @description  Adds an "Open video" link for tweets whith an embedded video
// @author       Simon Cambier
// @match        https://twitter.com/*
// @grant        none
// @run-at       document-idle
// ==/UserScript==

(function () {
  'use strict'

  setInterval(() => {
    createLink()
  }, 100)

  function createLink() {
    // If our custom link already exists, do nothing
    if (document.querySelectorAll('[data-media-download]')[0]) return

    // Find tweet
    const tweet = document.getElementsByClassName('permalink-inner permalink-tweet-container')[0]
    if (!tweet) return

    // Find video element
    const video = tweet.querySelectorAll('video')[0]
    if (!video) return
    const videoSrc = video.getAttribute('src')

    // Find actions bar
    const actions = tweet.getElementsByClassName('ProfileTweet-actionList')[0]
    if (!actions) return

    // Create link container
    const newItem = document.createElement('div')
    newItem.className = 'ProfileTweet-action'

    // Create the download link
    const link = document.createElement('a')
    link.className = 'ProfileTweet-actionButton js-actionButton'
    link.innerHTML = 'Open video'
    link.setAttribute('href', videoSrc)
    link.setAttribute('data-media-download', '')

    // Append elements
    newItem.appendChild(link)
    actions.appendChild(newItem)
  }

})();