chatwork-image-extractor.user.js

// ==UserScript==
// @name           ChatWork Image Extractor
// @description    Image extractor for ChatWork.
// @include        https://www.chatwork.com/*
// @version        0.0.1
// ==/UserScript==

(function(){
  function main(){
    var extractedList = []
    function extractImage(){
      var links = document.getElementsByTagName('a');
      var imageLinks = [];
      for( var i = 0, l = links.length; i < l; i++) {
        var el = links[i];
        var href = el.href;
        if (href && href.match(/^https:\/\/.+(jpeg|jpg|gif|png)$/)) {
          imageLinks.push(el)
        }
      }

      imageLinks.forEach(function(el){
        for(var i = 0, l = extractedList.length; i < l; i++){
          if (extractedList[i] == el) {
            return;
          }
        }
        var url = el.href;
        var img = document.createElement('img');
        img.src = url;
        window.removeEventListener("DOMNodeInserted", extractImage, false);
        el.parentNode.appendChild(img);
        window.addEventListener("DOMNodeInserted", extractImage, false);
        extractedList.push(el);
      });
    }
    window.addEventListener("DOMNodeInserted", extractImage, false);
  }

  window.addEventListener('load', main, false);
})();