Capture HTML from the browser selection into Emacs as org-mode content
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README.org

org-protocol-capture-html

org-protocol is awesome, but browsers do a pretty poor job of turning a page’s HTML content into plain-text. However, Pandoc supports converting from HTML to org-mode, so we can use it to turn HTML into Org-mode content! It can even turn HTML tables into Org tables!

Screenshot

Here’s an example of what you get in Emacs from capturing this page:

screenshot.png

Contents

Requirements

  • org-protocol: This is what connects org-mode to the “outside world” using a MIME protocol handler. The instructions on the org-protocol page are a bit out of date, so you might want to try these instructions instead.
  • s.el
  • Pandoc: Version 1.8 or later is required.
  • The shell script uses curl to download URLs (if you use it in that mode).

Installation

Emacs

Put org-protocol-capture-html.el in your load-path and add to your init file:

(require 'org-protocol-capture-html)

org-capture Template

You need a suitable org-capture template. I recommend this one. Whatever you choose, the default selection key is w, so if you want to use a different key, you’ll need to modify the script and the bookmarklets.

("w" "Web site" entry
  (file "")
  "* %a :website:\n\n%U %?\n\n%:initial")

Bookmarklets

Now you need to make a bookmarklet in your browser(s) of choice. You can select text in the page when you capture and it will be copied into the template, or you can just capture the page title and URL. A selection-grabbing function is used to capture the selection.

Note: The w in the URL in these bookmarklets chooses the corresponding capture template. You can leave it out if you want to be prompted for the template, or change it to another letter for a different template key.

Firefox

This bookmarklet captures what is currently selected in the browser. Or if nothing is selected, it just captures the page’s URL and title.

javascript:location.href = 'org-protocol://capture-html?template=w&url=' + encodeURIComponent(location.href) + '&title=' + encodeURIComponent(document.title || "[untitled page]") + '&body=' + encodeURIComponent(function () {var html = ""; if (typeof document.getSelection != "undefined") {var sel = document.getSelection(); if (sel.rangeCount) {var container = document.createElement("div"); for (var i = 0, len = sel.rangeCount; i < len; ++i) {container.appendChild(sel.getRangeAt(i).cloneContents());} html = container.innerHTML;}} else if (typeof document.selection != "undefined") {if (document.selection.type == "Text") {html = document.selection.createRange().htmlText;}} var relToAbs = function (href) {var a = document.createElement("a"); a.href = href; var abs = a.protocol + "//" + a.host + a.pathname + a.search + a.hash; a.remove(); return abs;}; var elementTypes = [['a', 'href'], ['img', 'src']]; var div = document.createElement('div'); div.innerHTML = html; elementTypes.map(function(elementType) {var elements = div.getElementsByTagName(elementType[0]); for (var i = 0; i < elements.length; i++) {elements[i].setAttribute(elementType[1], relToAbs(elements[i].getAttribute(elementType[1])));}}); return div.innerHTML;}());

This one uses eww’s built-in readability-scoring function in Emacs 25.1 and up to capture the article or main content of the page.

javascript:location.href = 'org-protocol://capture-eww-readable?template=w&url=' + encodeURIComponent(location.href) + '&title=' + encodeURIComponent(document.title || "[untitled page]");

Note: When you click on one of these bookmarklets for the first time, Firefox will ask what program to use to handle the org-protocol protocol. You can simply choose the default program that appears (org-protocol).

Pentadactyl

If you use Pentadactyl, you can use the Firefox bookmarklets above, or you can put these commands in your .pentadactylrc:

map -modes=n,v ch -javascript content.location.href = 'org-protocol://capture-html?template=w&url=' + encodeURIComponent(content.location.href) + '&title=' + encodeURIComponent(content.document.title || "[untitled page]") + '&body=' + encodeURIComponent(function () {var html = ""; if (typeof content.document.getSelection != "undefined") {var sel = content.document.getSelection(); if (sel.rangeCount) {var container = document.createElement("div"); for (var i = 0, len = sel.rangeCount; i < len; ++i) {container.appendChild(sel.getRangeAt(i).cloneContents());} html = container.innerHTML;}} else if (typeof document.selection != "undefined") {if (document.selection.type == "Text") {html = document.selection.createRange().htmlText;}} var relToAbs = function (href) {var a = content.document.createElement("a"); a.href = href; var abs = a.protocol + "//" + a.host + a.pathname + a.search + a.hash; a.remove(); return abs;}; var elementTypes = [['a', 'href'], ['img', 'src']]; var div = content.document.createElement('div'); div.innerHTML = html; elementTypes.map(function(elementType) {var elements = div.getElementsByTagName(elementType[0]); for (var i = 0; i < elements.length; i++) {elements[i].setAttribute(elementType[1], relToAbs(elements[i].getAttribute(elementType[1])));}}); return div.innerHTML;}())

map -modes=n,v ce -javascript location.href='org-protocol://capture-eww-readable?template=w&url='+encodeURIComponent(content.location.href)+'&title='+encodeURIComponent(content.document.title || "[untitled page]")

Note: The JavaScript objects are slightly different for running as Pentadactyl commands since it has its own chrome.

Chrome

These bookmarklets work in Chrome:

javascript:location.href = 'org-protocol:///capture-html?template=w&url=' + encodeURIComponent(location.href) + '&title=' + encodeURIComponent(document.title || "[untitled page]") + '&body=' + encodeURIComponent(function () {var html = ""; if (typeof window.getSelection != "undefined") {var sel = window.getSelection(); if (sel.rangeCount) {var container = document.createElement("div"); for (var i = 0, len = sel.rangeCount; i < len; ++i) {container.appendChild(sel.getRangeAt(i).cloneContents());} html = container.innerHTML;}} else if (typeof document.selection != "undefined") {if (document.selection.type == "Text") {html = document.selection.createRange().htmlText;}} var relToAbs = function (href) {var a = document.createElement("a"); a.href = href; var abs = a.protocol + "//" + a.host + a.pathname + a.search + a.hash; a.remove(); return abs;}; var elementTypes = [['a', 'href'], ['img', 'src']]; var div = document.createElement('div'); div.innerHTML = html; elementTypes.map(function(elementType) {var elements = div.getElementsByTagName(elementType[0]); for (var i = 0; i < elements.length; i++) {elements[i].setAttribute(elementType[1], relToAbs(elements[i].getAttribute(elementType[1])));}}); return div.innerHTML;}());

javascript:location.href = 'org-protocol:///capture-eww-readable?template=w&url=' + encodeURIComponent(location.href) + '&title=' + encodeURIComponent(document.title || "[untitled page]");

Note: The first sets of slashes are tripled compared to the Firefox bookmarklets. When testing with Chrome, I found that xdg-open was collapsing the double-slashes into single-slashes, which breaks org-protocol. I’m not sure why that doesn’t seem to be necessary for Firefox. If you have any trouble with this, you might try removing the extra slashes.

Shell script

The shell script is handy for piping any HTML (or plain-text) content to Org through the shell, or downloading and capturing any URL directly (without a browser), but it’s not required. It requires getopt, part of the util-linux package which should be standard on most Linux distros. On OS X you may need to install getopt or util-linux from MacPorts or Homebrew, etc.

You can use it like this:

org-protocol-capture-html.sh [OPTIONS] [HTML]
cat html | org-protocol-capture-html.sh [OPTIONS]

Send HTML to Emacs through org-protocol, passing it through Pandoc to
convert HTML to Org-mode.  HTML may be passed as an argument or
through STDIN.  If only URL is given, it will be downloaded and its
contents used.

Options:
    -h, --heading HEADING     Heading
    -r, --readability         Capture web page article with eww-readable
    -t, --template TEMPLATE   org-capture template key (default: w)
    -u, --url URL             URL

    --debug  Print debug info
    --help   I need somebody!

Usage

After installing the bookmarklets, you can select some text on a web page with your mouse, open the bookmarklet with the browser, and Emacs should pop up an Org capture buffer. You can also do it without selecting text first, if you just want to capture a link to the page.

You can also pass data through the shell script, for example:

dmesg | grep -i sata | org-protocol-capture-html.sh --heading "dmesg SATA messages" --template i

org-protocol-capture-html.sh --readability --url "https://lwn.net/Articles/615220/"

org-protocol-capture-html.sh -h "TODO Feed the cat!" -t i "He gets grouchy if I forget!"

Changelog

<2017-04-17>

  • Use s.el.
  • Handle empty titles from dom.
  • Skip HTTP headers more reliably in the eww-readable support.

<2017-04-15>

  • Switch from old-style org-protocol links to the new-style ones used in Org 9. Note: This requires updating existing bookmarklets to use the new-style links. See the examples in the usage instructions. Users who are unable to upgrade to Org 9 should use the previous version of this package.
  • Remove python-readability support and just use eww-readable. eww-readable seems to work so well that it seems unnecessary to bother with external tools. Of course, this does require Emacs 25.1, so users on Emacs 24 may wish to use the previous version.

<2017-04-11>

  • Add org-protocol-capture-eww-readable. For Emacs 25.1 and up, this uses eww’s built-in readability-style function instead of calling external Python scripts.

<2016-10-23 Sun>

  • Add org-protocol-capture-html-demote-times variable, which controls how many times headings in captured pages are demoted. This is handy if you use a sub-heading in your capture template, so you can make all the headings in captured pages lower than the lowest-level heading in your capture template.

<2016-10-05 Wed>

  • Check Pandoc’s no-wrap option lazily (upon first capture), and if Pandoc takes too long for some reason, try again next time a capture is run.
  • If Pandoc does take too long, kill the buffer and process without prompting.
  • Use sleep-for instead of sit-for to work around any potential issues with whatever “input” may interrupt sit-for.

Hopefully this puts issue #12 to rest for good. Thanks to @jguenther for his help fixing and reporting bugs.

<2016-10-03 Mon>

  • Handle pages without titles in bookmarklet examples. If a page lacks an HTML title, the string passed to org-protocol would have nothing where the title should go, and this would cause the capture to fail. Now the bookmarklets will use [untitled page] instead of an empty string. (No Elisp code changed, only the examples in the readme.)

<2016-10-01 Sat>

  • Use a temp buffer for the Pandoc test, thanks to @jguenther.

<2016-09-29 Thu>

  • Fix issue #12 (i.e. really fix the --no-wrap deprecation), thanks to @jguenther.
  • Require cl and use cl-incf instead of incf.

<2016-09-23 Fri>

  • Fix for Pandoc versions >= 1.16, which deprecates --no-wrap in favor of --wrap=none.

<2016-04-03 Sun>

<2016-03-23 Wed>

  • Add URL downloading to the shell script. Now you can run org-protocol-capture-html.sh -u http://example.com and it will download and capture the page.
  • Add org-capture template to the readme. This will make it much easier for new users.

Credits

  • Thanks to @jguenther for helping to fix issue #12.
  • Thanks to @xuchunyang for finding and fixing #17 and #19.

Appendix

org-protocol Instructions

1. Add protocol handler

Create the file ~/.local/share/applications/org-protocol.desktop containing:

[Desktop Entry]
Name=org-protocol
Exec=emacsclient %u
Type=Application
Terminal=false
Categories=System;
MimeType=x-scheme-handler/org-protocol;

Note: Each line’s key must be capitalized exactly as displayed, or it will be an invalid .desktop file.

Then update ~/.local/share/applications/mimeinfo.cache by running:

  • On KDE: kbuildsycoca4
  • On GNOME: update-desktop-database ~/.local/share/applications/

2. Configure Emacs

Init file

Add to your Emacs init file:

(server-start)
(require 'org-protocol)

Capture template

You’ll probably want to add a capture template something like this:

("w" "Web site"
 entry (file+olp "~/org/inbox.org" "Web")
 "* %c :website:\n%U %?%:initial")

Note: Using %:initial instead of %i seems to handle multi-line content better.

This will result in a capture like this:

* [[http://orgmode.org/worg/org-contrib/org-protocol.html][org-protocol.el – Intercept calls from emacsclient to trigger custom actions]] :website:
[2015-09-29 Tue 11:09] About org-protocol.el org-protocol.el is based on code and ideas from org-annotation-helper.el and org-browser-url.el.

3. Configure Firefox

On some versions of Firefox, it may be necessary to add this setting. You may skip this step and come back to it if you get an error saying that Firefox doesn’t know how to handle org-protocol links.

Open about:config and create a new boolean value named network.protocol-handler.expose.org-protocol and set it to true.

Note: If you do skip this step, and you do encounter the error, Firefox may replace all open tabs in the window with the error message, making it difficult or impossible to recover those tabs. It’s best to use a new window with a throwaway tab to test this setup until you know it’s working.

Selection-grabbing function

This function gets the HTML from the browser’s selection. It’s from this answer on StackOverflow.

function () {
    var html = "";

    if (typeof content.document.getSelection != "undefined") {
        var sel = content.document.getSelection();
        if (sel.rangeCount) {
            var container = document.createElement("div");
            for (var i = 0, len = sel.rangeCount; i < len; ++i) {
                container.appendChild(sel.getRangeAt(i).cloneContents());
            }
            html = container.innerHTML;
        }
    } else if (typeof document.selection != "undefined") {
        if (document.selection.type == "Text") {
            html = document.selection.createRange().htmlText;
        }
    }

    var relToAbs = function (href) {
        var a = content.document.createElement("a");
        a.href = href;
        var abs = a.protocol + "//" + a.host + a.pathname + a.search + a.hash;
        a.remove();
        return abs;
    };
    var elementTypes = [
        ['a', 'href'],
        ['img', 'src']
    ];

    var div = content.document.createElement('div');
    div.innerHTML = html;

    elementTypes.map(function(elementType) {
        var elements = div.getElementsByTagName(elementType[0]);
        for (var i = 0; i < elements.length; i++) {
            elements[i].setAttribute(elementType[1], relToAbs(elements[i].getAttribute(elementType[1])));
        }
    });
    return div.innerHTML;
}

Here’s a one-line version of it, better for pasting into bookmarklets and such:

function () {var html = ""; if (typeof content.document.getSelection != "undefined") {var sel = content.document.getSelection(); if (sel.rangeCount) {var container = document.createElement("div"); for (var i = 0, len = sel.rangeCount; i < len; ++i) {container.appendChild(sel.getRangeAt(i).cloneContents());} html = container.innerHTML;}} else if (typeof document.selection != "undefined") {if (document.selection.type == "Text") {html = document.selection.createRange().htmlText;}} var relToAbs = function (href) {var a = content.document.createElement("a"); a.href = href; var abs = a.protocol + "//" + a.host + a.pathname + a.search + a.hash; a.remove(); return abs;}; var elementTypes = [['a', 'href'], ['img', 'src']]; var div = content.document.createElement('div'); div.innerHTML = html; elementTypes.map(function(elementType) {var elements = div.getElementsByTagName(elementType[0]); for (var i = 0; i < elements.length; i++) {elements[i].setAttribute(elementType[1], relToAbs(elements[i].getAttribute(elementType[1])));}}); return div.innerHTML;}

To-Do

Add link to Mac OS X article

This article would be helpful for Mac users in setting up org-protocol.

File-based capturing

Pentadactyl has the :write command, which can write a page’s HTML to a file, or to a command, like :write !org-protocol-capture-html.sh. This should make it easy to implement file-based capturing, which would pass HTML through a temp file rather than as an argument, and this would work around the argument-length limit that we occasionally run into.

All that should be necessary is to:

  1. Add a new sub-protocol capture-file that receives a path to a file instead of a URL to a page.
    • It should probably delete the file after finishing the capture, to avoid leaving temp files laying around, so it should protect against deleting random files. Probably the best way to do this would be to define a directory and a prefix, and any files not in that directory and not having that prefix should not be deleted.
  2. Add a options to org-protocol-capture-html.sh to capture with files.
    • This should have two methods:
      • Pass the path to an existing file, which will then be passed to Emacs.
      • Pass content via STDIN, write it to a tempfile, and pass the tempfile’s path to Emacs. The tempfile should go in the directory and have the prefix so that Emacs knows it’s safe to delete that file.
  3. Document how to integrate this with Pentadactyl. It should be very simple, like :write !org-protocol-capture-html --tempfile.
    • This would, by default, pass the entire content of the page. It would be good to also be able to capture only the selection, and to be able to use Readability on the result. Here’s an example from the Pentadactyl manual that seems to show using JavaScript to fill arguments to the command:
:com! search-selection,ss -bang -nargs=? -complete search
\ -js commands.execute((bang ? open : tabopen )
\ + args + + buffer.currentWord)

However, I don’t see how this would allow writing different content to STDIN, only arguments. So this might not be possible without modifying Pentadactyl and/or using a separate Firefox extension. Here is the source for the :write command, and here for the underlying JS function. And you can see here how it uses temp files to pass STDIN to commands.

Handle long chunks of HTML

If you try to capture too long a chunk of HTML, it will fail with “argument list too long errors” from emacsclient. To work around this will require capturing via STDIN instead of arguments. Since org-protocol is based on using URLs, this will probably require using a shell script and a new Emacs function, and perhaps another MIME protocol-handler. Even then, it might still run into problems, because the data is passed to the shell script as an argument in the protocol-handler. Working around that would probably require a non-protocol-handler-based method using a browser extension to send the HTML directly via STDIN. Might be possible with Pentadactyl instead of making an entirely new browser extension. Also, maybe the Org-mode Capture Firefox extension could be extended (…) to do this.

However, most of the time, this is not a problem.

Package for MELPA

This would be nice.