GitHub Collapse In Comment

A userscript that adds a header that can toggle long code and quote blocks in comments

As of 27.06.2016. See апошняя версія.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         GitHub Collapse In Comment
// @version      1.0.0
// @description  A userscript that adds a header that can toggle long code and quote blocks in comments
// @license      https://creativecommons.org/licenses/by-sa/4.0/
// @namespace    https://github.com/Mottie
// @include      https://github.com/*
// @include      https://gist.github.com/*
// @run-at       document-idle
// @grant        GM_addStyle
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_registerMenuCommand
// @author       Rob Garrison
// ==/UserScript==
/* global GM_addStyle, GM_getValue, GM_setValue, GM_registerMenuCommand */
/* jshint esnext:true, unused:true */
(() => {
  "use strict";
  /*
   Idea from: https://github.com/dear-github/dear-github/issues/166 & https://github.com/isaacs/github/issues/208
   examples:
    https://github.com/Mottie/tablesorter/issues/569
    https://github.com/jquery/jquery/issues/3195
  */
  let targets, timer,

  // syntax highlight class name lookup table
  syntaxClass = {
    "basic"  : "HTML",
    "cs"     : "C#",
    "fsharp" : "F#",
    "gfm"    : "Markdown",
    "jq"     : "JSONiq",
    "shell"  : "Bash (shell)",
    "tcl"    : "Glyph",
    "tex"    : "LaTex"
  },

  // hide code/quotes longer than this number of lines
  minLines = GM_getValue("gcic-max-lines", 10),
  startCollapsed = GM_getValue("gcic-start-collapsed", true),

  busy = false;

  GM_addStyle(`
    .gcic-block {
      border:#eee 1px solid;
      padding:2px 8px 2px 10px;
      border-radius:5px 5px 0 0;
      position:relative;
      top:1px;
      cursor:pointer;
      font-weight:bold;
    }
    .gcic-block + .highlight {
      border-top:none;
    }
    .gcic-block + .email-signature-reply {
      margin-top:0;
    }
    .gcic-block:after {
      content:"\u25bc ";
      float:right;
    }
    .gcic-block-closed {
      border-radius:5px;
      margin-bottom:10px;
    }
    .gcic-block-closed:after {
      content:"\u25C4 ";
      float:right;
    }
    .gcic-block-closed + .highlight, .gcic-block-closed + .email-signature-reply,
    .gcic-block-closed + pre {
      display:none;
    }
  `);

  function makeToggle(name, lines) {
    /* full list of class names from
    https://github.com/github/linguist/blob/master/lib/linguist/languages.yml (look at "tm_scope" value)
    here are some example syntax highlighted class names:
      highlight-text-html-markdown-source-gfm-apib
      highlight-text-html-basic
      highlight-source-fortran-modern
      highlight-text-tex
    */
    let n = (name || "")
      .replace(/(highlight[-\s]|(source-)|(text-)|(html-)|(markdown-)|(-modern))/g, "");
    n = (syntaxClass[n] || n).toUpperCase().trim();
    return `${n || "Block"} (${lines} lines)`;
  }

  function addToggles() {
    busy = true;
    // issue comments
    if ($("#discussion_bucket")) {
      let loop,
        indx = 0,
        block = document.createElement("div"),
        els = $$(".markdown-body pre, .email-signature-reply"),
        len = els.length;

      // "flash" = blue box styling
      block.className = "gcic-block border flash" + (startCollapsed ? " gcic-block-closed" : "");

      // loop with delay to allow user interaction
      loop = () => {
        let el, wrap, node, syntaxClass, numberOfLines,
          // max number of DOM insertions per loop
          max = 0;
        while ( max < 20 && indx < len ) {
          if (indx >= len) { return; }
          el = els[indx];
          if (el && !el.classList.contains("gcic-has-toggle")) {
            numberOfLines = el.innerHTML.split("\n").length;
            if (numberOfLines > minLines) {
              syntaxClass = "";
              wrap = closest(el, ".highlight");
              if (wrap && wrap.classList.contains("highlight")) {
                syntaxClass = wrap.className;
              } else {
                // no syntax highlighter defined (not wrapped)
                wrap = el;
              }
              node = block.cloneNode();
              node.innerHTML = makeToggle(syntaxClass, numberOfLines);
              wrap.parentNode.insertBefore(node, wrap);
              el.classList.add("gcic-has-toggle");
              if (startCollapsed) {
                el.display = "none";
              }
              max++;
            }
          }
          indx++;
        }
        if (indx < len) {
          setTimeout(() => {
            loop();
          }, 200);
        }
      };
      loop();
    }
    busy = false;
  }

  function addBindings() {
    document.addEventListener("click", event => {
      let els, indx, flag,
        el = event.target;
      if (el && el.classList.contains("gcic-block")) {
        // shift + click = toggle all blocks in a single comment
        // shift + ctrl + click = toggle all blocks on page
        if (event.shiftKey) {
          els = $$(".gcic-block", event.ctrlKey ? "" : closest(el, ".markdown-body"));
          indx = els.length;
          flag = el.classList.contains("gcic-block-closed");
          while (indx--) {
            els[indx].classList[flag ? "remove" : "add"]("gcic-block-closed");
          }
        } else {
          el.classList.toggle("gcic-block-closed");
        }
        removeSelection();
      }
    });
  }

  function update() {
    busy = true;
    let toggles = $$(".gcic-block"),
      indx = toggles.length;
    while (indx--) {
      toggles[indx].parentNode.removeChild(toggles[indx]);
    }
    toggles = $$(".gcic-has-toggle");
    indx = toggles.length;
    while (indx--) {
      toggles[indx].classList.remove("gcic-has-toggle");
    }
    addToggles();
  }

  function $(selector, el) {
    return (el || document).querySelector(selector);
  }
  function $$(selector, el) {
    return Array.from((el || document).querySelectorAll(selector));
  }
  function closest(el, selector) {
    while (el && el.nodeName !== "BODY" && !el.matches(selector)) {
      el = el.parentNode;
    }
    return el && el.matches(selector) ? el : null;
  }
  function removeSelection() {
    // remove text selection - http://stackoverflow.com/a/3171348/145346
    var sel = window.getSelection ? window.getSelection() : document.selection;
    if (sel) {
      if (sel.removeAllRanges) {
        sel.removeAllRanges();
      } else if (sel.empty) {
        sel.empty();
      }
    }
  }

  GM_registerMenuCommand("Set GitHub Collapse In Comment Max Lines", () => {
    let val = prompt("Minimum number of lines before adding a toggle:", minLines);
    val = parseInt(val, 10);
    if (val) {
      minLines = val;
      GM_setValue("gcic-max-lines", val);
      update();
    }
  });
  GM_registerMenuCommand("Set GitHub Collapse In Comment Initial State", () => {
    let val = prompt("Start with blocks collapsed?", !startCollapsed);
    if (val) {
      val = /^t/.test(val || "");
      startCollapsed = val;
      GM_setValue("gcic-start-collapsed", val);
      update();
    }
  });

  targets = $$("#js-repo-pjax-container, #js-pjax-container");

  Array.prototype.forEach.call(targets, target => {
    new MutationObserver(mutations => {
      mutations.forEach(mutation => {
        let mtarget = mutation.target;
        // preform checks before adding code wrap to minimize function calls
        // update after comments are edited
        if (!busy && (mtarget === target || mtarget.matches(".js-comment-body, .js-preview-body"))) {
          clearTimeout(timer);
          timer = setTimeout(() => {
            addToggles();
          }, 100);
        }
      });
    }).observe(target, {
      childList: true,
      subtree: true
    });
  });

  addBindings();
  addToggles();

})();