Firefox/Chrome extension to capture links to slack messages

This extension hijacks the "Add to saved items" button in Slack, and replaces it with an org-protocol call.

It also works around the super-annoying feature of Slack permalinks where it tries to navigate to a slack:// URI when you visit a message link. It will now automagically follow the "Open in browser" link.

How to use

Find a message that you want to record. Click the unicorn button:

Emacs will then open a capture buffer containing a link to the message, which you can edit then file away in your TODO list.

At a later time, you can revisit the Slack message by typing C-c C-o on the link.

Installing

Check out the source code, run:

npm install
npm run build

Firefox

1. Navigate to about:debugging#/runtime/this-firefox
2. Select This Firefox and expand the Temporary Extensions section.
3. Click Load Temporary Add-on... and select ./dist/firefox/manifest.json.

The extension will eventually be published on addons.mozilla.org/.../org-capture-slack.

Chrome

(Chrome version may be broken at the moment ... I have been using Firefox).

1. Navigate to chrome://extensions
2. Enable Developer Mode.
3. Click Load Unpacked and add the ./dist/chrome/ directory as an "Unpacked Extension."

Configuration

You need to have org-protocl set up properly to begin with. So emacsclient and a URL scheme handler for org-protocol:// need to be configured. Follow the instructions in the org-mode Manual then add the browser bookmarklet to check that it works.

The org-mode side is configured in a similar manner to org-capture-extension.

Add something like the following to your org-capture-templates:

(setq org-capture-templates
  '(("lm" "Slack message link" entry
      (file+headline org-default-notes-file "Slack inbox")
      "* TODO %?
  SCHEDULED: %t
  :LOGBOOK:
  - Captured: %U
  :END:

  [[%:link][%:description]]
  #+BEGIN_QUOTE
  %i
  #+END_QUOTE

")))

The capture key is hard-coded to lm.

Extra configuration

Here are some extra things you can configure.

Nix home-manager

Add the following module to your user's home-manager config to set up URL scheme handlers:

{
  home-manager.users.MYUSERNAME = { pkgs, ... }: {
    # Enable emacs service and emacsclient
    programs.emacs.enable = true;
    services.emacs = {
      enable = true;
      client.enable = true;
      socketActivation.enable = true;
    };

    # Install desktop file for org-protocol://
    home.packages = [ (pkgs.makeDesktopItem {
      name = "org-protocol";
      desktopName = "org-protocol";
      icon = "emacs";
      exec = "emacsclient %u";
      categories = "System";
      mimeType = "x-scheme-handler/org-protocol";
    }) ];

    xdg.mimeApps = {
      enable = true;
      # Associate org-protocol:// with emacsclient
      defaultApplications."x-scheme-handler/org-protocol" = "org-protocol.desktop";
      # Disable slack:// URL handler
      associations.removed."x-scheme-handler/slack" = "slack.desktop";
    };
  };
}

Emacs link opening

If you want Emacs to open links in eww or Emacs W3 by default, but still open Slack message links in Chrome, then add something like this to .emacs:

(setq browse-url-browser-function
      '(("^/" . browse-url-emacs)
        ("\\`[^:]+\\'" . browse-url-emacs)
        ("\\`file://" . browse-url-emacs)
        ("https://.*\\.slack.com.*" . browse-url-xdg-open)
        ("." . eww-browse-url)))

It assumes that your browse-url-xdg-open function will run Chrome.

Getting your Slack API key

If you look in the javascript console of your Slack tab, you should see your Slack session token logged by this extension. This can be useful to have if you would like to try some Slack API calls, etc.

Work in progress

This code works for me on Firefox, but is still under development.

TODO

• Remove example code from chrome extensions tutorial.
• Convert UTC timestamps to local timezone.
• Allow configuration of the org-capture key (currently hardcoded to "lm").
• Find a way to block the permalink page from opening the slack:// URI.
• Also capture the thread topic message, if the message was in a thread.
• Add a button to show the Slack auth token that was found by this extension.
• Add "quickview" of links to GitHub/Jira issues. So user can just hover over the link to see a preview of its content.
• Add Firefox version.
• Unbreak Chrome version.