View difference between Paste ID: qdDGcMjB and sKhjS7Da

 // ==UserScript==
 // @name         Hide thread iichan
 // @namespace    http://iichan.hk/
 // @license      WTFPL
 // @version      0.1
 // @description  adds hide thread feature to iichan
 // @author       Cirno
 // @match        http://iichan.hk/*
 // @grant        none
 // ==/UserScript==
 
 (function() {
     'use strict';
 
     var THREAD_TITLE_LENGTH = 50;  // Сколько первых символов из поста показывать в заголовке скрытого треда
 
     function removeClass(element, className) {
         var reg = new RegExp('(\\s|^)' + className + '(\\s|$)');
         element.className = element.className.replace(reg, ' ');
     }
 
     function addHideBtns() {
         var threads = document.querySelectorAll('[id^=thread]');
         for (var i = threads.length - 1; i >= 0; i--) {
             var thread = threads[i];
             var label = thread.querySelector('label');
             if (!label) continue;
             var btn = document.createElement('a');
             btn.innerHTML = '[-]';
             btn.className = 'iichan-hide-thread-btn';
             btn.title = 'Скрыть тред';
-            btn.addEventListener('click', function() {hideThread(thread.id);});
+            btn.threadId = thread.id;
             btn.addEventListener('click', function() {hideThread(this.threadId);});
             thread.insertBefore(btn, label.nextSibling);
         }
     }
 
     function unHideThread(threadId) {
         var hiddenThreads = JSON.parse(window.localStorage.getItem('iichan_hidden_threads') || "[]");
         var index = hiddenThreads.indexOf(threadId);
         if (index === -1) {
             return;
         }
         hiddenThreads.splice(index, 1);
         window.localStorage.setItem('iichan_hidden_threads', JSON.stringify(hiddenThreads));
 
         var thread = document.getElementById(threadId);
         if(!thread) {
             return;
         }
         removeClass(thread, 'iichan-thread-hidden');
         var placeholder = document.getElementById('iichan-hidden-' + threadId);
         if (placeholder) {
             placeholder.parentElement.removeChild(placeholder);
         }
     }
 
     function hideThread(threadId) {
         var thread = document.getElementById(threadId);
         if(!thread) {
             return;
         }
         var parent = thread.parentNode;
         var threadHiddenDiv = document.createElement('div');
         var threadNo = threadId.split('-')[1];
         var threadTitle = thread.querySelector('.filetitle').innerText || thread.querySelector('blockquote').innerText || 'картинка';
         threadTitle = threadTitle.substr(0, THREAD_TITLE_LENGTH);
         threadHiddenDiv.innerHTML = 'Тред №' + threadNo + ' скрыт (' + threadTitle + ')';
         threadHiddenDiv.id = 'iichan-hidden-' + threadId;
         threadHiddenDiv.className = 'reply iichan-hidden-thread-placeholder';
         threadHiddenDiv.addEventListener('click', function() {unHideThread(threadId);});
         thread.className += ' iichan-thread-hidden';
         parent.insertBefore(threadHiddenDiv, thread);
 
         // save result
         var hiddenThreads = JSON.parse(window.localStorage.getItem('iichan_hidden_threads') || "[]");
         if (hiddenThreads.indexOf(threadId) === -1) {
             hiddenThreads.push(threadId);
             window.localStorage.setItem('iichan_hidden_threads', JSON.stringify(hiddenThreads));
         }
     }
 
     function hideAllHiddenThreads() {
         var hiddenThreads = JSON.parse(window.localStorage.getItem('iichan_hidden_threads') || "[]");
         for (var i = hiddenThreads.length - 1; i >= 0; i--) {
             hideThread(hiddenThreads[i]);
         }
     }
 
     function appendCSS() {
         var css = document.createElement('style');
         css.type = 'text/css';
         css.innerHTML =  '\
 .iichan-hidden-thread-placeholder {\
 cursor: pointer;\
 }\
 .iichan-hidden-thread-placeholder:hover + div, .iichan-hidden-thread-placeholder:hover + div + br {\
 display: block !important;\
 }\
 .iichan-thread-hidden {\
 display: none;\
 }\
 .iichan-thread-hidden + br {\
 display: none;\
 }\
 .iichan-hide-thread-btn {\
 margin-left: 0.2em;\
 cursor: pointer;\
 }\
 ';
         document.body.appendChild(css);
     }
 
     appendCSS();
     addHideBtns();
     hideAllHiddenThreads();
 })();