gistfile1.js

// ==UserScript==
// @name           Motsu Tabetai
// @namespace      http://ikenie.com/
// @include        *
// @require http://gist.github.com/raw/3242/1a7950e033a207efcfc233ae8d9939b676bdbf46
// @require http://gist.github.com/raw/34615/04333b7e307eb029462680e4f4cf961f72f4324c

// ==/UserScript==

(function() {
  var DATABASE_URL = 'http://wedata.net/databases/Motsu/items.json';
  var map = {}, words = [];

  function replacer(str) {
    return ['<img src="', map[str], '" alt="', str, '"/>'].join('');
  }

  function motsu(doc) {
      $X('//text()', doc).forEach(function(textNode) {
        var data = textNode.data;

        if(data.match(words.join('|'))) {
          var replaced = data.replace(new RegExp(words.join('|'),
          'g'), replacer);
          var div = document.createElement('div');
          var range = document.createRange();

          div.innerHTML = replaced;
          range.selectNodeContents(div);
          var df = range.extractContents();
          range.setStartBefore(textNode);
          range.insertNode(df);
          range.selectNode(textNode);
          range.deleteContents();
        }
      });
  }
  var database = new Wedata.Database(DATABASE_URL);
  if (document.referrer.match(/http:\/\/wedata\.net\/.*\/[new|edit]/) &&
      document.location.href.match(/http:\/\/wedata\.net\/items\/\d+/)) {
    database.clearCache();
    database = new Wedata.Database(DATABASE_URL);
  }
  
  database.get(function(items) {
    items.forEach(function(item) {
      map[item.name] = item.data.image_url;
    });

    for(var i in map) {
      words.push(i);
    }
    
    motsu(document);
  });

  GM_registerMenuCommand('Motsu Tabetai - clear cache', function() {
    database.clearCache();
  });

  setTimeout(function() {
    if (window.AutoPagerize && window.AutoPagerize.addDocumentFilter)
    {
      window.AutoPagerize.addDocumentFilter(motsu);
    }
  }, 0);
})();