WaniKani override, fixed for Greasemonkey

wkoverride.user.js

// ==UserScript==
// @name        Wanikani Override
// @namespace   wkoverride
// @description Adds an "Ignore Answer" button during reviews that makes WaniKani ignore the current answer (useful if, for example, you made a stupid typo)
// @include     http://www.wanikani.com/review/session*
// @include     https://www.wanikani.com/review/session*
// @version     1.1.3
// @author      Rui Pinheiro
// @grant       GM_addStyle
// @grant       unsafeWindow
// @require     http://code.jquery.com/jquery-1.11.2.min.js
// @license     GPL version 3 or any later version; http://www.gnu.org/copyleft/gpl.html
// ==/UserScript==
/*
 *  ====  Wanikani  Override  ====
 *    ==   by Rui Pinheiro   ==
 *
 *  One of my biggest peeves with Wanikani is how once you get something wrong,
 *  you can't change it. If you type too fast and make a typo, or if the spell checker
 *  doesn't	like you, you're out of luck. It's really frustrating to know an answer but
 *  have Wanikani deny it to you because it wants the '-ing' form of the verb, but you
 *  typed the infinitive.
 *  Sometimes you get lucky, and the spell checker is lenient enough to mark the answer
 *  correctly. Other times, that's not the case.
 *  Then, there's the other type of mistakes. The ones where you type a reading but were
 *  supposed to type a meaning, or the opposite. Those are really annoying, since most
 *  times you actually knew the correct reading or meaning respectively.
 *
 *
 *  My problem is that the decision was completely out of my hands. My objective is to
 *  learn Kanji, and I'm not going to cheat since that wouldn't bring me closer to where
 *  I want to be, but Wanikani decides that I can't be trusted and does not let me correct it.
 *
 *  But now, with the client-side reviews update, we can finally do something about all this!
 *
 *
 *
 *  This userscript fixes this problem, by adding an "Ignore Answer" button to the footer
 *  during reviews. This button can be clicked anytime an answer has been marked as wrong by
 *  Wanikani.
 *
 *  Once clicked, the current answer will be changed from "incorrect" (red background)
 *  to "ignored" (yellow background), and Wanikani will forget you even answered it.
 *  This way, the item will appear again later on during the review cycle, effectively
 *  giving you a second chance to get it right without stupid typos or the spell checker
 *  getting in the way.
 *
 *
 *  DISCLAIMER:
 *  I am not responsible for any problems caused by this script.
 *  This script was developed on Firefox 25.0.1 with Greasemonkey 1.12.
 *  It was also tested on Chrome 31.0.1650.57 with Tampermonkey 3.5.3630.77.
 *  Because I'm just one person, I can't guarantee the script works anywhere else.
 *
 *  Also, anyone using this script is responsible for using it correctly.
 *  This should be used only if you make an honest mistake but actually knew the correct
 *  answer. Using it in any other way will harm your Kanji learning process,
 *  cheating will only make learning Japanese harder and you'll end up harming only yourselves!
 */
/*
 *	This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/*
 *	=== Changelog ===
 *
 *  1.1.2 (11 March 2014)
 *  - Relicensed under the GPLv3.
 *
 *  1.1.1 (23 January 2014)
 *  - Now supports the HTTPS protocol.
 *
 *  1.1.0 (24 November 2013)
 *  - Previously ignored answers can be unignored by pressing the 'Ignore' button again before skipping to the next question.
 *  - Code cleaned up, added debug functionality and better error logging (like all my other Wanikani scripts)
 *
 *  1.0.5 (7 November 2013)
 *  - Ignores '~' hotkey if pressed while editing an item's notes.
 *
 *  1.0.4 (14 August 2013)
 *  - Fixed the '~' hotkey in Chrome.
 *
 *  1.0.3 (5 August 2013)
 *  - Wanikani update changed the review URL. While the script worked, it also affected the reviews summary page. This has been fixed
 *
 *  1.0.2 (29 July 2013)
 *  - Made '~' a hotkey, as requested by some users of the Wanikani forums.
 *  - Script now updates the question count and error count correctly.
 *
 *  1.0.1 (24 July 2013)
 *  - Fixed a bug that would cause "Null" to appear instead of "Reading" or "Meaning" after ignoring a certain Vocabulary.
 *  - Tested the script on Google Chrome with Tampermonkey (the script does not work natively).
 *
 *  1.0.0 (23 July 2013)
 *  - First release.
 *
 */
/*
 * Debug Settings
 */
var debugLogEnabled = false;
var scriptShortName = 'WKO';
scriptLog = debugLogEnabled ? function (msg) {
  if (typeof msg === 'string') {
    console.log(scriptShortName + ': ' + msg);
  } else {
    console.log(msg);
  }
}
 : function () {
};
/*
 * Other settings
 */
var prefAllowUnignore = true;
/*
 * "Ignore Answer" Button Click
 */
var ActionEnum = Object.freeze({
  ignore: 0,
  unignore: 1
});
function WKO_ignoreAnswer()
{
  try
  {
    /* Check if the current item was answered incorrectly */
    var elmnts = document.getElementsByClassName('incorrect');
    var elmnts2 = document.getElementsByClassName('WKO_ignored');
    
    var curAction;
    if (!isEmpty(elmnts[0])) // Current answer is wrong
    curAction = ActionEnum.ignore;
     else if (prefAllowUnignore && !isEmpty(elmnts2[0])) // Current answer is ignored
    curAction = ActionEnum.unignore;
     else
    // Either there is no current answer, or it's correct
    {
      alert('WKO: Current item wasn\'t answered incorrectly, nor ignored previously!');
      return false;
    }

    /* Grab information about current question */
    var curItem = $.jStorage.get('currentItem');
    var questionType = $.jStorage.get('questionType');

    /* Build item name */
    var itemName;
    if (curItem.rad)
    itemName = 'r';
     else if (curItem.kan)
    itemName = 'k';
     else
    itemName = 'v';
    itemName += curItem.id;
    scriptLog(itemName);
    /* Grab item from jStorage.
		 * 
		 * item.rc and item.mc => Reading/Meaning Completed (if answered the item correctly)
		 * item.ri and item.mi => Reading/Meaning Invalid (number of mistakes before answering correctly)
		 */
    var item = $.jStorage.get(itemName) || {
    };
    /* Update the item data */
    if (questionType === 'meaning')
    {
      if (!('mi' in item) || isEmpty(item.mi))
      {
        throw Error('item.mi undefined');
        return false;
      } 
      else if (item.mi < 0 || (item.mi == 0 && curAction == ActionEnum.ignore))
      {
        throw Error('item.mi too small');
        return false;
      }
      if (curAction == ActionEnum.ignore)
      item.mi -= 1;
       else
      item.mi += 1;
      delete item.mc;
    } 
    else
    {
      if (!('ri' in item) || isEmpty(item.ri))
      {
        throw Error('item.ri undefined');
        return false;
      } 
      else if (item.ri < 0 || (item.ri == 0 && curAction == ActionEnum.ignore))
      {
        throw Error('i.ri too small');
        return false;
      }
      if (curAction == ActionEnum.ignore)
      item.ri -= 1;
       else
      item.ri += 1;
      delete item.rc;
    }
    /* Save the new state back into jStorage */

    $.jStorage.set(itemName, item);
    /* Modify the questions counter and wrong counter and change the style of the answer field */
    var wrongCount = $.jStorage.get('wrongCount');
    var questionCount = $.jStorage.get('questionCount');
    if (curAction == ActionEnum.ignore)
    {
      $.jStorage.set('wrongCount', wrongCount - 1);
      $.jStorage.set('questionCount', questionCount - 1);
      $('#answer-form fieldset').removeClass('incorrect');
      $('#answer-form fieldset').addClass('WKO_ignored');
    } 
    else
    {
      $.jStorage.set('wrongCount', wrongCount + 1);
      $.jStorage.set('questionCount', questionCount + 1);
      $('#answer-form fieldset').removeClass('WKO_ignored');
      $('#answer-form fieldset').addClass('incorrect');
    }
    return true;
  } 
  catch (err) {
    logError(err);
  }
}
/*
 * Bind '~' as a hotkey 
 */

function bindHotkey()
{
  jQuery(document).on('keydown.reviewScreen', function (event)
  {
    if ($('#reviews').is(':visible') && !$('*:focus').is('textarea, input'))
    {
      //alert('keycode: ' + event.keyCode);
      switch (event.keyCode) {
        case 176: //Firefox '~'
        case 192: //Chrome '~'
          event.stopPropagation();
          event.preventDefault();
          if ($('#user-response').is(':disabled'))
           WKO_ignoreAnswer();
          return false;
          break;
      }
    }
  });
}
/*
 * Inject Ignore Button
 */

function addIgnoreAnswerBtn()
{
  var footer = document.getElementsByTagName('footer'),
      $btn = jQuery('<div id="WKO_button" title="Ignore Answer">Ignore Answer</div>').on('click', WKO_ignoreAnswer);
  jQuery(footer[0]).prepend($btn);
}
/*
 * Prepares the script
 */

function scriptInit()
{
  // Add global CSS styles
  GM_addStyle('#WKO_button {background-color: #CC0000; color: #FFFFFF; cursor: pointer; display: inline-block; font-size: 0.8125em; padding: 10px; vertical-align: bottom;}');
  GM_addStyle('#answer-form fieldset.WKO_ignored input[type="text"]:-moz-placeholder, #answer-form fieldset.WKO_ignored input[type="text"]:-moz-placeholder {color: #FFFFFF; font-family: "Source Sans Pro",sans-serif; font-weight: 300; text-shadow: none; transition: color 0.15s linear 0s; } #answer-form fieldset.WKO_ignored button, #answer-form fieldset.WKO_ignored input[type="text"], #answer-form fieldset.WKO_ignored input[type="text"]:disabled { background-color: #FFCC00 !important; }');
  scriptLog('loaded');
  // Set up hooks
  try
  {
    addIgnoreAnswerBtn();
    bindHotkey();
  } 
  catch (err) {
    logError(err);
  }
}
/*
 * Helper Functions/Variables
 */

//use 'jQuery' for greasemonkey's version, $ is WK's jQuery
$ = unsafeWindow.$;

function isEmpty(value) {
  return (typeof value === 'undefined' || value === null);
}
/*
 * Error handling
 * Can use 'error.stack', not cross-browser (though it should work on Firefox and Chrome)
 */

function logError(error)
{
  var stackMessage = '';
  if ('stack' in error)
  stackMessage = '\n\tStack: ' + error.stack;
  console.error(scriptShortName + ' Error: ' + error.name + '\n\tMessage: ' + error.message + stackMessage);
}
/*
 * Start the script
 */

scriptInit();

Thank you