javascript 自定义 id class 选择器实现 支持链式操作

(function() {
	return window.Query = window.$ = function() {
		var _this = {}, selector = arguments[0];
		$.prototype = _this;
		/**
		 * 判断是对象是数组还是名值对象
		 * 返回0表示是数组，返回1表示是名值对象
		 */
		function objOrArr(obj) {
			if (!obj)
				return;
			if (typeof obj === "object") {
				for (var attr in obj) {
					return 1;
				}
				return obj.push ? 0 : 1;
			}
		}

		/**
		 * 确保所有对象都能call
		 */
		function applyAll(obj, callback) {
			if (!obj)
				return;
			var idx = 0
			if (objOrArr(obj)) {
				for (var i in obj) {
					if (callback.call(obj[i], i, obj[i]) === false) {
						break;
					}
				}
			} else {
				for (var o = obj[0]; idx < obj.length&& callback.call(o, idx, o) !== false; o = obj[++idx]) {
				}
			}
		}

		/**
		 * id选择器
		 */
		function identity(selector) {
			if (selector) {
				return document.getElementById(selector);
			}
		}

		/**
		 * 类选择器
		 */
		function clazz(selector) {
			var result = [];
			if (selector) {
				var a = selector.split(".");
				var prefix = a[0] || "*";
				var suffix = a[1];
				applyAll(document.getElementsByTagName(prefix), function() {
					if (this.nodeType === 1 && this.id) {
						var classNames = this.className.split(/\s+/g);
						var finded = this;
						applyAll(classNames, function() {
							if (this == suffix) {
								result.push(finded);
							}
						});
					} else {
					}
				});
			}
			return result;
		}

		if (selector) {
			if (typeof selector === "string") {
				if (selector.indexOf(".") != -1)
					return clazz(selector);
				if (selector.indexOf("#") != -1){
					return identity(selector.substring(selector.indexOf("#")+1));
				}else{
					return document.getElementsByTagName(selector);
				}
			}
			if (typeof selector === "object") {
				_this[0] = selector;
				return _this[0];
			}
			if (typeof selector === "function") {
				return selector(_this);	// selector 就是传入的function
			}
		} else {
			_this.toString();
		}
		_this.toString = function() {
			return "[Query query]";
		}
		return _this;
	}
})();

/**
 * 简易弹出框
 */
$.pop = function(url, title, options) {
	if(options){
		window.open(url,title,options)
	}else{
	    window.open(url,title,'height=350,width=800,top=200,left=300,toolbar=no,menubar=no,scrollbars=no,resizable=no,location=no,status=no')
	}
},
/**
 * 简易ajax请求
 */
$.ajax = function(options) {
	var httpRequest = window.ActiveXObject? new ActiveXObject("Microsoft.XMLHTTP"): new XMLHttpRequest();httpRequest.onreadystatechange = function() {
		var dataType = options.dataType.toLowerCase();
		httpRequest.readyState === 4&& httpRequest.status === 200&& options.callback(dataType === "json" ? eval("("	+ httpRequest.responseText + ")") : dataType === "xml"? httpRequest.responseXML: httpRequest.responseText, options.context);
	};
	httpRequest.open(options.mode, options.url, options.sync);
	if(options.mode.toLowerCase() === "post"){
		httpRequest.setRequestHeader("CONTENT-TYPE", "application/x-www-form-urlencoded");
	}
	options.mode.toLowerCase() === "get" ? httpRequest.send(null):httpRequest.send(options.params);
},
/**
 * 去除所有空格
 */
$.trim = function(str) {
	return str.replace(/(^\s*)|(\s*$)/g,"");
},
/**
 * 去除左边空格
 */
$.ltrim = function(str) {
	return str.replace(/(^\s*)/g, "");
},
/**
 * 去除右边空格
 */
$.rtrim = function(str) {
	return str.replace(/(\s*$)/g, "");
}