Node Mutation Hook Library

A small wrapper around MutationObserver to hook into creation of elements (filtered on CSS selector) or removal of nodes.

Detta skript bör inte installeras direkt. Det är ett bibliotek för andra skript att inkludera med meta-direktivet // @require https://update.greasyfork.org/scripts/565361/1755404/Node%20Mutation%20Hook%20Library.js

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// ==UserScript==
// @name        Node Mutation Hook Library
// @namespace   https://greasyfork.org/users/1545341
// @version     2.1.0
// @license     MIT
// @author      abcenjoyer
// @description A small wrapper around MutationObserver to hook into creation of elements (filtered on CSS selector) or removal of nodes.
// ==/UserScript==

function hookCreation(selector, callback) {
  const observer = new MutationObserver((mutations) => {
    for (const record of mutations) {
      for (const node of record.addedNodes) {
        if (node.nodeType === Node.ELEMENT_NODE) {
          if (node.matches(selector)) {
            callback(node, observer);
          }

          for (const element of node.querySelectorAll(selector)) {
            callback(element, observer);
          }
        }
      }
    }
  });

  observer.observe(document.documentElement, {
    childList: true,
    subtree: true
  });
}

function hookRemoval(targetNode, callback) {
  const observer = new MutationObserver((mutations) => {
    for (const record of mutations) {
      for (const node of record.removedNodes) {
          if (node.contains(targetNode)) {
            observer.disconnect();
            callback();
          }
      }
    }
  });

  // observing the entire document is required because if targetNode is deleted because an ancestor node was, observing the parent won't work
  observer.observe(document, {
    childList: true,
    subtree: true
  });
}