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waitForElement

Waits for an element using the MutationObserver API

当前为 2025-03-04 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/528234/1546775/waitForElement.js 

  1. // ==UserScript==
  2. // @name         waitForElement
  3. // @namespace    Violentmonkey Scripts
  4. // @version      1.2
  5. // @description  Waits for an element using the MutationObserver API
  6. // @author       maanimis
  7. // @grant        none
  8. // ==/UserScript==
  9.  
  10. /**
  11.  * Waits for a element of a given selector.
  12.  *
  13.  * @param {string} selector
  14.  * @returns {Promise<HTMLElement>}
  15.  */
  16.  
  17.  function waitForElement(selector) {
  18.   return new Promise((resolve) => {
  19.     const ELEMENT = document.querySelector(selector);
  20.     if (ELEMENT) {
  21.       return resolve(ELEMENT);
  22.     }
  23.  
  24.     console.log("can't find element for selector:", selector, "waiting...");
  25.  
  26.     const observer = new MutationObserver(() => {
  27.       const ELEMENT = document.querySelector(selector);
  28.       if (ELEMENT) {
  29.         console.log("element found!!");
  30.         resolve(ELEMENT);
  31.         observer.disconnect();
  32.       }
  33.     });
  34.  
  35.     observer.observe(document.body, {
  36.       childList: true,
  37.       subtree: true,
  38.     });
  39.   });
  40. }