Question

My extension is simply performing actions on pages based on user clicks; it works fine on all websites except for Gmail.

Here’s my manifest file:

{
  "name": "My Extension",
  "version": "2.0",
  "description": "description.",
  "permissions": [
    "tabs"
  ],
  "icons": {
    "16" : "images/icon-16.png",
    "48" : "images/icon-48.png",
    "128" : "images/icon-128.png"
  },
  "background_page": "background.html",
  "options_page": "Options.html",
  "content_scripts": [
    {
        "matches": ["<all_urls>"],
        "css": ["css/style.css"],
        "js": ["inject.js"]
    }
  ]
}

When I click on a web page, my inject.js normally fires an alert() — it handles onclick events. But, on Gmail pages, it does not catch the click event.

Answer 1

Gmail is composed of frames. By default, content scripts are only injected at the top-level frame. Add "all_frames":true to the manifest, so that the content script is also injected in the frames.

"content_scripts": [{
    "matches": ["<all_urls>"],
    "css": ["css/style.css"],
    "js": ["inject.js"],
    "all_frames": true
}]