• Posts
  • RSS
  • ◂◂RSS
  • Contact

  • Auto-Downloder Chrome Extension

    September 18th, 2021
    comments, tech  [html]
    Let's say you want Chrome to automatically download pieces of pages, such as Facebook comments. How could you do it? I recently wanted to do this and couldn't find docs, so here's what I did.

    1. Make a folder somewhere for a browser extension.

    2. In that folder, make manifest.json with contents like:

        "name": "Downloader",
        "description": "Downloads stuff",
        "version": "1.0",
        "manifest_version": 3,
        "permissions": [
        "background": {
          "service_worker": "background.js"
        "content_scripts": [{
          "matches": [
          "js": ["content_script.js"]
    3. In content_script.js put:

      // This file extracts what you want from the page
      // and asks the background script to save it.
      // You write the code to extract what you want.
      const yourStringToSave =
          /* extension id not needed */ undefined,
    4. In background.js put:

      // This file receives messages from the content
      // script and puts them in your Dowloads folder.
      function makeDataUrl(body) {
        // We use a data: url because Chrome has
        // trouble with object URLs in Incognito.
        return "data:application/json;base64," +
        function(message) {
          const fname = message[0];
          const body = message[1];
            conflictAction: "overwrite",
            filename: fname,
            url: makeDataUrl(body),
    5. Visit chrome://extensions

    6. Enable Developer Mode

    7. Click the "Load unpacked" and select the extension directory

    8. If you need it in Incognito, click "Details" on the extension card and then enable "Allow in Incognito".

    Example code: github.

    (And, yes, this is how Facebook comments are back.)

    Comment via: facebook, lesswrong

    Recent posts on blogs I like:

    EDT with updating double counts

    I recently got confused thinking about the following case: Calculator bet: I am offered the opportunity to bet on a mathematical statement X to which I initially assign 50% probability (perhaps X = 139926 is a quadratic residue modulo 314159). I have acce…

    via The sideways view October 12, 2021

    Meditations on newborns

    [Content: death.]I wrote most of this a couple of months ago when Nora was a newborn, but the first few months are not that conducive to finishing blog posts. New babies put you into a liminal period, both in your own experience and in how others treat yo…

    via The whole sky October 3, 2021

    The value of in-house expertise

    An alternate title for this post might be, "Twitter has a kernel team!?". At this point, I've heard that surprised exclamation enough that I've lost count of the number times that's been said to me (I'd guess that it's more tha…

    via Posts on Dan Luu September 29, 2021

    more     (via openring)

  • Posts
  • RSS
  • ◂◂RSS
  • Contact