Observe

Observe and wait for elements

Fra og med 12.10.2025. Se den nyeste version.

Dette script bør ikke installeres direkte. Det er et bibliotek, som andre scripts kan inkludere med metadirektivet // @require https://update.greasyfork.org/scripts/552301/1675980/Observe.js

// ==UserScript==
// @name         Observe
// @license      MIT
// @version      2.0
// @description  Observe and wait for elements
// @author       tukars
// @match        *://*/*
// @require      https://update.greasyfork.org/scripts/552322/1675979/Namespace.js
// ==/UserScript==

const NAMESPACE = { author: "tukars", library: "Observe" };

(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 } 
	) { 
		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; }
			
			timeoutId = setTimeout(() => {
				observer.disconnect();
				reject(new Error(`waitForElement timed out after ${timeoutMs}ms for selector: "${selector}"`));
			}, timeoutMs);
		});
	}

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