query

query.js

function initPage() {
	console.log(Q('div#wrapper.list[type="tset"][test="123"]'));
}




window.Q = function( selector, paren ) {
	var Q = function ( selector, parent ) {
		
		var regs = {
			'id' : /\#[\w\d-]+/,
			'classes' : /\.[\w\d-]+/g,
			'tag' : /^[\w]+/,
			'attr' : /\[([\w]+)\=("|')([\w\d-]+)("|')\]/g
		};
		
		/*function parseSelector(selector) {
			var token = selector;
		}*/
		
		/**
		 * @param {String} selector
		 * @returns {Object}
		 * */
		function parseSelectorToken(selector) {
			var key = null,
				res = {};
			
			for(key in regs) {
				var tokens = selector.match(regs[key]);
				if (!tokens) continue;
				 if (key === 'id' || key === 'classes') {
					res[key] = map(tokens, function(item, index) {
						//removing first '.' and '#' char
						return item.replace(/^\#|\./, '');
					});
				} else if (key === 'attr') {
					res[key] = map(tokens, function(item, index) {
						// Convert token '[type="test"]' to 'type=test'
						var attrs = item.replace(/\[|\]|"|'/g, '').split('=');
						return {
							name : attrs[0],
							value : attrs[1]
						};
					});
				} else {
					res[key] = tokens;
				}
			}
			return res;
		}
		
		/**
		 * @param {Object} selectorObj
		 * */
		function getElement(selectorObj) {
			if (isEmptyObj(selectorObj)) return false;
			if (!selectorObj.id) {
				return byId(selectorObj.id[0]);
			} else if (!selectorObj.classes) {
				return byClass(selectorObj.classes.join(' '));
			} else if (!selectorObj.tag) {
				return byTag(selectorObj.tag[0]);
			} else {
				var attrs = selectorObj.attr,
					elems = document.getElementsByTagName('*'),
					attrsLen = attrs.length,
					elemsLen = elems.length,
					i = 0,
					j = 0,
					counter = 0,
					res = [];
				for (i; i < elemsLen; i++) {
					for (j = 0; j < attrsLen; j++) {
						if (elems[i].getAttribute(attrs[j].name) === attrs[j].value ) {
							counter++;
						}
					}
					if (counter === attrsLen) {
						res.push(elems[i]);
					}
					counter = 0;
				}
				console.log(res);
				return res;
			}
		}
		
		console.log(getElement(parseSelectorToken(selector)));
		
		/**
		 * @param {Array} item
		 * @returns {Boolean}
		 * */
		function isArray(item) {
			return item instanceof Array;
		}
		
		/**
		 * @param {String} node
		 * @returns {Node}
		 * */
		function byId(node) {
			return document.getElementById(node);
		}
		
		/**
		 * @param {String} classList
		 * @returns {Array | NodeList}
		 * */
		function byClass(classList) {
			if (document.getElementsByClassName) {
				return document.getElementsByClassName(classList);
			}
			var list = document.getElementsByTagName('*'), 
				length = list.length,  
				classArray = classList.split(/\s+/), 
				classes = classArray.length, 
				result = [], i,j;
			for (i = 0; i < length; i++) {
				for (j = 0; j < classes; j++)  {
					if(list[i].className.search('\\b' + classArray[j] + '\\b') != -1) {
						result.push(list[i]);
						break;
					};
				};
			}
			return result;
		}
		
		/**
		 * @param {String} tagName
		 * @returns {NodeList}
		 * */
		function byTag(tagName) {
			return document.getElementsByTagName(tagName);
		}
		
		/**
		 * @param {Array} items
		 * @param {Function} handler
		 * @returns {Array}
		 * */
		function map(items, handler) {
			var i = 0,
				len = items.length,
				res = [];
			
			for (i; i < len; i++) {
				res.push(handler(items[i], i));
			}
			return res;
		}
		
		/**
		 * @param {Array} items
		 * @param {Function} handler
		 * @returns {Array}
		 * */
		function grep(items, handler) {
			var i = 0,
				len = items.length,
				res = [];
			for(i; i < len; i++) {
				if (handler(items[i], i)) {
					res.push(items[i]);
				};
			}
			return res;
		};
		
		/**
		 * @param {Array} items
		 * @param {Function} handler
		 * @returns {Boolean}
		 * */
		function every(items, handler) {
			var len = items.length,
				arr = null;
			arr = grep(items, handler);
			
			return arr.length === len;
		}
		
		/**
		 * @param {String} str
		 * @returns {String}
		 * */
		function trim(str) {
			console.log(str)
			return str.replace(/^[\s]|[\s]$/, '');
		}
		
		/**
		 * @param {String} str
		 * @returns {String}
		 * */
		function normalizeSpaces(str) {
			return str.replace(/\s+/g, ' ');
		}
		
		/**
		 * @param {Object} obj
		 * @returns {Boolean}
		 * */
		function isEmptyObj(obj) {
			var key = null,
				len = 0;
			for (key in obj) {
				len+=1;
			}
			return !len;
		}
		
		/**@param {HTMLElement}
		 * @param {String} classList
		 * @returns {Boolean}
		 * */
		function hasClass(elem, classList) {
			var classes = normalizeSpaces(trim(classList)).split(' ');
			classes
		}
		
		hasClass(null,'wer dv sdf ')
	};
	
	return new Q( selector, parent );
};





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