waitForKeyElements utility function

A utility function for userscripts that detects and handles AJAXed content.

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.gf.qytechs.cn/scripts/446257/1059316/waitForKeyElements%20utility%20function.js

您需要先安装一个扩展,例如 篡改猴Greasemonkey暴力猴,之后才能安装此脚本。

You will need to install an extension such as Tampermonkey to install this script.

您需要先安装一个扩展,例如 篡改猴暴力猴,之后才能安装此脚本。

您需要先安装一个扩展,例如 篡改猴Userscripts ,之后才能安装此脚本。

您需要先安装一款用户脚本管理器扩展,例如 Tampermonkey,才能安装此脚本。

您需要先安装用户脚本管理器扩展后才能安装此脚本。

(我已经安装了用户脚本管理器,让我安装!)

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展,比如 Stylus,才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

您需要先安装一款用户样式管理器扩展后才能安装此样式。

(我已经安装了用户样式管理器,让我安装!)

// ==UserScript==
// @version 1.0.0
// @name waitForKeyElements utility function
// @description A utility function for userscripts that detects and handles AJAXed content.
// @namespace https://github.com/CoeJoder/waitForKeyElements.js
// @author CoeJoder
// @homepage https://github.com/CoeJoder/waitForKeyElements.js
// @source https://raw.githubusercontent.com/CoeJoder/waitForKeyElements.js/master/waitForKeyElements.js
// 
// ==/UserScript==

/**
 * A utility function for userscripts that detects and handles AJAXed content.
 *
 * Usage example:
 *
 *     function callback(domElement) {
 *         domElement.innerHTML = "This text inserted by waitForKeyElements().";
 *     }
 * 
 *     waitForKeyElements("div.comments", callback);
 *     // or
 *     waitForKeyElements(selectorFunction, callback);
 *
 * @param {(string|function)} selectorOrFunction - The selector string or function.
 * @param {function} callback - The callback function; takes a single DOM element as parameter.
 *                              If returns true, element will be processed again on subsequent iterations.
 * @param {boolean} [waitOnce=true] - Whether to stop after the first elements are found.
 * @param {number} [interval=300] - The time (ms) to wait between iterations.
 * @param {number} [maxIntervals=-1] - The max number of intervals to run (negative number for unlimited).
 */
function waitForKeyElements(selectorOrFunction, callback, waitOnce, interval, maxIntervals) {
	if (typeof waitOnce === "undefined") {
		waitOnce = true;
	}
	if (typeof interval === "undefined") {
		interval = 300;
	}
	if (typeof maxIntervals === "undefined") {
		maxIntervals = -1;
	}
	var targetNodes = (typeof selectorOrFunction === "function")
			? selectorOrFunction()
			: document.querySelectorAll(selectorOrFunction);

	var targetsFound = targetNodes && targetNodes.length > 0;
	if (targetsFound) {
		targetNodes.forEach(function(targetNode) {
			var attrAlreadyFound = "data-userscript-alreadyFound";
			var alreadyFound = targetNode.getAttribute(attrAlreadyFound) || false;
			if (!alreadyFound) {
				var cancelFound = callback(targetNode);
				if (cancelFound) {
					targetsFound = false;
				}
				else {
					targetNode.setAttribute(attrAlreadyFound, true);
				}
			}
		});
	}

	if (maxIntervals !== 0 && !(targetsFound && waitOnce)) {
		maxIntervals -= 1;
		setTimeout(function() {
			waitForKeyElements(selectorOrFunction, callback, waitOnce, interval, maxIntervals);
		}, interval);
	}
}