Observe

Observe and wait for elements

Dieses Skript sollte nicht direkt installiert werden. Es handelt sich hier um eine Bibliothek für andere Skripte, welche über folgenden Befehl in den Metadaten eines Skriptes eingebunden wird // @require https://update.greasyfork.org/scripts/552301/1676523/Observe.js

// ==UserScript==
// @name         Observe
// @license      MIT
// @version      2.2
// @description  Observe and wait for elements
// @author       tukars
// @match        *://*/*
// ==/UserScript==

(function () {
	const timeStamp = function () {
		const now = new Date();
		const pad = (num, size) => String(num).padStart(size, "0");

		const hours = pad(now.getHours(), 2);
		const minutes = pad(now.getMinutes(), 2);
		const seconds = pad(now.getSeconds(), 2);
		const milliseconds = pad(now.getMilliseconds(), 3);

		return `${hours}:${minutes}:${seconds}.${milliseconds}`;
	};

	const contextPrint = function (message, ENABLE_DEBUG_LOGGING) {
		const messageTime = () => `[${message}] ${timeStamp()} -`;

		const log = function (...args) {
			console.log(messageTime(), ...args);
		};
		const warn = function (...args) {
			console.warn(messageTime(), ...args);
		};
		const error = function (...args) {
			console.error(messageTime(), ...args);
		};
		const info = function (...args) {
			console.info(messageTime(), ...args);
		};
		var debug = function (...args) {
			console.debug(messageTime(), ...args);
		};
		if (!ENABLE_DEBUG_LOGGING) {
			debug = function () { };
		}

		return { log, warn, error, info, debug };
	};

	const observeChildren = function (element, config, callback) {
		const observer = new MutationObserver((mutationsList) => {
			for (const mutation of mutationsList) {
				if (mutation.type === "childList") {
					callback(Array.from(mutation.addedNodes));
				}
			}
		});
		const use_config = config || { childList: true, subtree: false };
		observer.observe(element, use_config);
		return observer;
	};

	const observeChildrenWithFilter = function (element, config, filter, callback) {
		return observeChildren(element, config, (addedNodes) =>
			callback(addedNodes.filter(filter))
		);
	};
	
	const observeChildrenWithSelector = function(element, config, selector, callback) {
		return observeChildrenWithFilter(
			element,
			config,
			(node) =>
				node.nodeType === Node.ELEMENT_NODE &&
				node.matches(selector),
			callback
		);
	};
	
	const observeAndHandle = function(
		element, selector, fun, config = { childList: true, subtree: true } 
	) { 
		return observeChildrenWithSelector(element, config, selector, (nodes) => 
			nodes.forEach((node) => fun(node))
		);
	};

	async function waitForElement(selector, timeoutMs = 0, parent = document) {
		return new Promise((resolve, reject) => {
			const element = parent.querySelector(selector);
			if (element) {
				resolve(element);
				return;
			}
			const observer = observeChildren(parent, { childList: true, subtree: true }, () => {
				const el = parent.querySelector(selector);
				if (!el) { return; }
				
				observer.disconnect();
				resolve(el);
			});
			
			if (timeoutMs == 0) { return; }
			
			setTimeout(() => {
				observer.disconnect();
				reject(new Error(`waitForElement timed out after ${timeoutMs}ms for selector: "${selector}"`));
			}, timeoutMs);
		});
	}
	
	const NAMESPACE = { author: "tukars", library: "Observe" };
	const assign = function (namespace, object) {
		const root = "userscript";
		const domain = "com";
		const author = namespace.author;
		const library = namespace.library;
		window[root] = window[root] || {};
		window[root][domain] = window[root][domain] || {};
		window[root][domain][author] = window[root][domain][author] || {};
		if (window[root][domain][author][library]) { return; }
		window[root][domain][author][library] = object;
	}

	assign(NAMESPACE, {
		timeStamp,
		contextPrint,
		observeChildren,
		observeChildrenWithFilter,
		observeChildrenWithSelector,
		observeAndHandle,
		waitForElement
	});
})();