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userscripts-core-library

Core library to handle webpages dom with userscripts from document-start

当前为 2023-09-24 提交的版本，查看 最新版本。

此脚本不应直接安装。它是供其他脚本使用的外部库，要使用该库请加入元指令 // @require https://update.cn-greasyfork.org/scripts/476017/1255617/userscripts-core-library.js 

  1. // ==UserScript==
  2. // @name        userscripts-core-library
  3. // @version     0.1.0
  4. // @author      lucianjp
  5. // @description Core library to handle webpages dom with userscripts from document-start
  6. // ==/UserScript==
  7.  
  8. const core = {
  9.   ready: (callback) =>
  10.     document.readyState !== "loading"
  11.       ? callback()
  12.       : document.addEventListener("DOMContentLoaded", callback),
  13.   addStyle: (aCss) => {
  14.     let head = document.getElementsByTagName("head")[0];
  15.     if (!head) {
  16.       console.error("Head element not found. Cannot add style.");
  17.       return null;
  18.     }
  19.  
  20.     let style = document.createElement("style");
  21.     style.setAttribute("type", "text/css");
  22.     style.textContent = aCss;
  23.     head.appendChild(style);
  24.     return style;
  25.   },
  26.   observe: (observableCollection, continuous = false) => {
  27.     const observables = Array.from(observableCollection.entries()).filter(
  28.       ([_, observable]) => !observable.currentValue
  29.     );
  30.  
  31.     const observer = new MutationObserver(function (mutations) {
  32.       for (var i = mutations.length - 1; i >= 0; i--) {
  33.         const mutation = mutations[i];
  34.         const addedNodesLength = mutation.addedNodes.length;
  35.         if (addedNodesLength > 0) {
  36.           for (var j = addedNodesLength - 1; j >= 0; j--) {
  37.             const $node = mutation.addedNodes[j];
  38.             if ($node && $node.nodeType === 1) {
  39.               let observablesLength = observables.length;
  40.               for (let k = observablesLength - 1; k >= 0; k--) {
  41.                 const [_, observable] = observables[k];
  42.  
  43.                 if (observable.test($node)) {
  44.                   observable.set($node);
  45.                   const last = observables.pop();
  46.                   if (k < observablesLength - 1) observables[k] = last;
  47.                   observablesLength = observablesLength - 1;
  48.                   break;
  49.                 }
  50.               }
  51.             }
  52.           }
  53.  
  54.           if (observables.length === 0 && !continuous) {
  55.             observer.disconnect();
  56.             return;
  57.           }
  58.         }
  59.       }
  60.     });
  61.  
  62.     observer.observe(document, { childList: true, subtree: true });
  63.  
  64.     if (!continuous) core.ready(() => observer.disconnect());
  65.  
  66.     return observer;
  67.   },
  68. };
  69.  
  70. class Observable {
  71.   constructor(lookup, test) {
  72.     this.value = undefined;
  73.     this.callbacks = [];
  74.     this.lookup = lookup;
  75.     this.test = test;
  76.  
  77.     if (typeof lookup === "function") {
  78.       this.value = lookup();
  79.     }
  80.   }
  81.  
  82.   set(newValue) {
  83.     this.value = newValue;
  84.     this.executeCallbacks(this.value);
  85.   }
  86.  
  87.   then(callback) {
  88.     if (typeof callback === "function") {
  89.       this.callbacks.push(callback);
  90.       if (this.value) callback(this.value);
  91.     }
  92.     return this;
  93.   }
  94.  
  95.   executeCallbacks(value) {
  96.     this.callbacks.forEach((callback) => callback(value));
  97.   }
  98.  
  99.   get currentValue() {
  100.     return this.value;
  101.   }
  102. }
  103.  
  104. class ObservableCollection extends Map {
  105.   constructor() {
  106.     super();
  107.   }
  108.  
  109.   add(name, observable) {
  110.     this.set(name, observable);
  111.     return observable;
  112.   }
  113. }