yssWaitForNode

Be smart!
当前为 2022-12-01 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.greasyfork.icu/scripts/454354/1123248/yssWaitForNode.js
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// ==UserScript==
// @name         yssWaitForNode
// @namespace    https://ysslang.com/
// @version      1.2.1
// @description  Be smart!
// @author       ysslang
// @match        *://*/*
// @note         https://greasyfork.org/scripts/454354
// @grant        none
// ==/UserScript==

class WaitForNode {
  #currentURL;
  #observerList = [];
  #waitList = [];

  constructor() { this.#currentURL = window.location.href; }

  #checkIfUrlMatch(matcher) {
    var result = false;
    if (matcher === undefined || matcher === null) result = false;
    if (typeof matcher === "string") result = new RegExp(matcher.trim()).test(this.#currentURL);
    if (matcher instanceof RegExp) result = matcher.test(this.#currentURL);
    return result;
  }

  #determineParentElement(arg) {
    var result = document.body;
    if (typeof arg === "string" && document.querySelector(arg)) result = document.querySelector(arg);
    if (arg instanceof Element) result = arg;
    return result;
  }

  #mergeOptions(options) {
    options = options || {};
    var result = {
      immediate: [options.immediate, options.imdt].find((e) => e) || true,
      recursive: [options.recursive, options.rcs].find((e) => e) || true,
      once: [options.once].find((e) => e) || false,
      subtree: [options.subtree, options.sbt].find((e) => e) || true,
      childList: [options.childList, options.cld].find((e) => e) || true,
      parentEl: this.#determineParentElement(options.parent),
    };
    return result;
  }

  #extractMatchedElements(mutations, selector, recursive) {
    const matchedElements = [];
    for (const { addedNodes } of mutations) {
      for (const node of addedNodes) {
        if (!node.tagName) continue;
        else if (node.matches(selector)) matchedElements.push(node);
        else if (recursive && node.firstElementChild) matchedElements.push(...node.querySelectorAll(selector));
      }
    }
    return matchedElements;
  }

  #on(selector, callback, options) {
    if (options.immediate) {
      [...options.parentEl.querySelectorAll(selector)].forEach(callback);
    }
    const observer = new MutationObserver((mutations) => {
      const elements = this.#extractMatchedElements(mutations, selector, options.recursive);
      elements.forEach(callback);
      if (elements && options.once) this.disconnect();
    });
    observer.observe(options.parentEl, { subtree: options.subtree, childList: options.childList, });
    this.#observerList.push(observer);
    return observer;
  }

  #injectStyle(styleString) {
    const style = document.createElement('style');
    style.textContent = styleString;
    return document.head.append(style);
  }

  add(name, url, selector, callback, options) {
    if(url === '') url = ['.*'];
    const urls = Array.isArray(url) ? url : [url];
    if (!urls.some(this.#checkIfUrlMatch, this)) return;
    const opts = this.#mergeOptions(options);
    const observer = this.#on(selector, callback, opts);
    this.#waitList.push({'name': name, 'url': url, 'selector': selector, 'callback': callback, 'options': opts, 'observer': observer});
  }

  addCss(name, url, cssString) {
    if(url === '') url = ['.*'];
    const urls = Array.isArray(url) ? url : [url];
    if (!urls.some(this.#checkIfUrlMatch, this)) return;
    this.#injectStyle(cssString);
  }

  stopAll() {
    while (this.#observerList.length) this.#observerList.pop().disconnect();
  }
}

const WFN = new WaitForNode();