Google Docs Preview Redirect Tampermonkey Script

google_doc_preview_tamperscript.js

// ==UserScript==
// @name         Preview Google Docs
// @version      1.0.0
// @description  Same you some CPU and RAM
// @author       Trevor Siemens
// @homepageUrl  https://gist.github.com/tsiemens/5d6507590a35ebde833b388e48510862
// @match        https://docs.google.com/document/d/*/edit*
// @match        https://docs.google.com/document/d/*/preview*
// @run-at       document-start
// @grant        GM_addStyle
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_registerMenuCommand
// @require      https://openuserjs.org/src/libs/sizzle/GM_config.min.js
// ==/UserScript==

// ***************************************************
// General utils
// ***************************************************
const logSig = "Preview Google Docs (tamper):";

// ***************************************************
// GM_config
// https://github.com/sizzlemctwizzle/GM_config/
// ***************************************************
const settingsFieldDefs = {
   'alwaysRedirectFrom': {
      'section': [GM_config.create("Auto-Redirection Rules"), "One URL regex per line"],
      'label': 'Always redirect to preview when coming from these domains',
      'labelPos': 'top',
      'type': 'textarea',
      'default': 'https?:\/\/aid[\.\/]'
   },
   'neverRedirectFrom': {
      'label': 'Do not ask or redirect to preview when coming from these domains',
      'labelPos': 'top',
      'type': 'textarea',
      'default': ''
   },
   'showPreviewPageSnackbar': {
      'section': "Preview page settings",
      'label': 'Show notification when redirected to preview page',
      'type': 'checkbox',
      'default': true
    }
};

function _addConfigErrorText(doc, parentElemId, id) {
   let parentGrp = doc.getElementById(parentElemId);
   let errorDiv = doc.createElement("div");
   errorDiv.setAttribute("id", id);
   errorDiv.className = "ugm_config_error_msg";
   parentGrp.appendChild(errorDiv);
   return errorDiv;
}

function _setConfigErrorMsg(configId, errorDiv) {
   let text = GM_config.get(configId);
   let res = _parsePatternsFromMultilineText(text);
   errorDiv.innerHTML = res.errors.join("\n");
}

function _getRegexTestMatches(configId, testUrl) {
   let text = GM_config.get(configId);
   let res = _parsePatternsFromMultilineText(text);
   let matches = [];
   for (let pattern of res.patterns) {
      if (testUrl.search(pattern) >= 0) {
         matches.push(pattern.toString());
      }
   }
   return matches;
}

var _updateRegexTestResult = null;

function _addRegexTestInput(doc) {
   let section0Container = doc.getElementById("GM_config_section_0");
   let inputWrapper = doc.createElement("div");
   inputWrapper.className = "config_var"; // Standard GM_config class for config styles
   // <input id="GM_config_field_name" type="text" size="25">
   // <label id="GM_config_name_field_label" for="GM_config_field_name" class="field_label">Name</label>
   let testInput = doc.createElement("input");
   testInput.setAttribute("id", "GM_config_regex_test_input");
   testInput.setAttribute("type", "text");
   testInput.setAttribute("size", "25");
   testInput.setAttribute("autocomplete", "off");
   inputWrapper.appendChild(testInput);
   let label = doc.createElement("label");
   label.className = "field_label"; // Standard GM_config class for config styles
   label.setAttribute("for", "GM_config_field_name");
   label.innerHTML = "Enter a URL here to test (save first)";
   inputWrapper.appendChild(label);
   section0Container.appendChild(inputWrapper);

   let testingResult = doc.createElement("p");
   testingResult.setAttribute("id", "GM_config_regex_test_output");
   section0Container.appendChild(testingResult);

   _updateRegexTestResult = () => {
      let matchesA = _getRegexTestMatches("alwaysRedirectFrom", testInput.value);
      let matchesN = _getRegexTestMatches("neverRedirectFrom", testInput.value);
      let matchText = "";
      let lines = [];
      if (matchesA.length > 0) {
         lines.push("Matches from 'always redirect' patterns:");
         for (let match of matchesA) {
            lines.push(match);
         }
      }
      if (matchesN.length > 0) {
         lines.push("Matches from 'never redirect' patterns:");
         for (let match of matchesN) {
            lines.push(match);
         }
      }
      if (lines.length == 0 && testInput.value.length > 0) {
         lines.push("No matching patterns");
      }

      testingResult.innerHTML = lines.join("<br>");
   };
   testInput.addEventListener('input', _updateRegexTestResult);
}

function _gmConfigInit() {
   // GM_config included from external lib
   'use strict';
   let context = {}

   GM_config.init(
   {
      id: 'GM_config',
      title: 'Preview Google Docs Settings',
      fields: settingsFieldDefs,
      css: `#GM_config_section_1 .config_var, #GM_config_section_2 .config_var, #GM_config_section_3 .config_var {
               margin: 5% !important;display: inline !important;
            }
           .ugm_config_error_msg {
             color: #f00;
           }`,
      events:
      {
         open: function(doc) {
            // Custom modifications to the settings panel can be made here.

            let errorDiv = _addConfigErrorText(doc, "GM_config_alwaysRedirectFrom_var",
                                               "GM_config_alwaysRedirectFrom_errors");
            context.alwaysRedirErrorDiv = errorDiv;
            errorDiv = _addConfigErrorText(doc, "GM_config_neverRedirectFrom_var",
                                           "GM_config_neverRedirectFrom_errors");
            context.neverRedirErrorDiv = errorDiv;

            _addRegexTestInput(doc);
         },
         save: function(values) {
            // All the values that aren't saved are passed to this function
            // for (i in values) alert(values[i]);
            _setConfigErrorMsg("alwaysRedirectFrom", context.alwaysRedirErrorDiv);
            _setConfigErrorMsg("neverRedirectFrom", context.neverRedirErrorDiv);
            _updateRegexTestResult();
         }
      }
   });
}

function _parsePatternsFromMultilineText(text) {
   let lines = text.split('\n');
   let patterns = [];
   let errors = [];
   for (let line of lines) {
      if (line.length > 0) {
         try {
            let pat = RegExp(line);
            patterns.push(pat);
         } catch (e) {
            errors.push("Error in \"" + line + "\" : " + e.message);
         }
      }
   }
   return {patterns: patterns, errors: errors};
}

function _getAlwaysRedirectFromList() {
   let text = GM_config.get("alwaysRedirectFrom");
   let res = _parsePatternsFromMultilineText(text);
   return res.patterns;
}

function _getNeverRedirectFromList() {
   let text = GM_config.get("neverRedirectFrom");
   let res = _parsePatternsFromMultilineText(text);
   return res.patterns;
}

// ***************************************************
// Preview page functions
// ***************************************************

function _addSnackbarStyles() {
   'use strict';
   GM_addStyle(`
#ugm_snackbar {
  visibility: hidden;
  min-width: 250px;
  margin-left: -125px;
  background-color: #333;
  color: #fff;
  text-align: center;
  border-radius: 2px;
  padding: 16px;
  position: fixed;
  z-index: 1000;
  left: 50%;
  bottom: 30px;
  font-size: 17px;
}

#ugm_snackbar.show {
  visibility: visible;
  // Each part is [ name, duration, delay (absolute) ]
  -webkit-animation: ugm_fadein 0.5s, ugm_fadeout 0.5s 2.5s, ugm_stayout 20s 3s;
  animation: ugm_fadein 0.5s, ugm_fadeout 0.5s 2.5s, ugm_stayout 20s 3s;
}

@-webkit-keyframes ugm_fadein {
  from {bottom: 0; opacity: 0;}
  to {bottom: 30px; opacity: 1;}
}

@keyframes ugm_fadein {
  from {bottom: 0; opacity: 0;}
  to {bottom: 30px; opacity: 1;}
}

@-webkit-keyframes ugm_fadeout {
  from {bottom: 30px; opacity: 1;}
  to {bottom: 0; opacity: 0;}
}

@keyframes ugm_fadeout {
  from {bottom: 30px; opacity: 1;}
  to {bottom: 0; opacity: 0;}
}

@-webkit-keyframes ugm_stayout {
  from {opacity: 0;}
  to {opacity: 0;}
}

@keyframes ugm_stayout {
  from {opacity: 0;}
  to {opacity: 0;}
}
`);
}

function _showSnackbar(text) {
   'use strict';
   let x = document.createElement("div");
   x.innerHTML = text;
   x.setAttribute("id", "ugm_snackbar");

   document.body.appendChild(x);
   // let initialDelay = 1000;
   let initialDelay = 1000;

   setTimeout(() => {
      x.className = "show";
      console.log("1");
      setTimeout(() => {
         console.log("2");
         x.className = x.className.replace("show", "");
         console.log("no show");
      }, 3000);
   },
   initialDelay);
   setTimeout(() => { document.body.removeChild(x); }, initialDelay + 5000);
}

function _handlePreviewPage() {
   if (!GM_config.get("showPreviewPageSnackbar")) {
      return;
   }

   window.addEventListener('load', function() {
      'use strict';
      _addSnackbarStyles();

      let referrer = document.referrer;
      console.log(logSig, "Referrer: \"" + referrer + "\"");

      if (referrer.search(RegExp("https://docs.google.com/document/d/.*/edit.*")) >= 0) {
         console.log(logSig, "Doc preview page was referred by edit page");
         _showSnackbar("Redirected from Google Doc editor (tampermonkey)");
      }
   }, false);
}

// ***************************************************
// Redirection functions
// ***************************************************

function _isRefresh() {
   'use strict';
   if (window.performance) {
      // performance is supported
      let navEntries = window.performance.getEntriesByType("navigation");
      if (navEntries.length == 0) {
         console.log(logSig, "Found no performance nagivation entries");
         return false;
      }
      let navType = navEntries[0].type;
      console.log(logSig, "navigation type: " + navType);
      return navType == "reload";
   }
   console.log(logSig, "window.performance not supported");
   return false;
}

// ***************************************************
// Script entry point
// ***************************************************
(function() {
   'use strict';
   _gmConfigInit();
   GM_registerMenuCommand('Settings', () => {
      console.log(logSig, "Open settings");
      GM_config.open();
   });

   if (window.location.href.match("https://docs.google.com/document/d/.*/preview")) {
      _handlePreviewPage();
      return;
   }

   let referrer = document.referrer;
   console.log(logSig, "Referrer: \"" + referrer + "\"");

   if (_isRefresh()) {
      // Do not apply on refresh. This would most likely just be annoying.
      return;
   }


   let noPrompt = false;
   for (let pattern of _getAlwaysRedirectFromList()) {
      if (referrer.search(pattern) >= 0) {
         console.log(logSig, "Auto-previewing (matched " + pattern + ")");
         noPrompt = true;
         break;
      }
   }

   for (let pattern of _getNeverRedirectFromList()) {
      if (referrer.search(pattern) >= 0) {
         console.log(logSig, "Not previewing (matched " + pattern + ")");
         return;
      }
   }

   if (noPrompt ||
       window.confirm("Preview Google Docs (Tampermonkey):\n\nOpen Google Doc in preview mode?")) {
      var url = window.location.href;
      var previewUrl = url.replace(RegExp("(.*/)edit(.*)"), "$1preview$2");
      window.location.replace(previewUrl);
   }
})();