stash.js

/*! Stash v1.2.4 MIT/GPL2 @rezitech */
(function (win, ls, doc) {

	// Returns whether a constructor is the constructor of a value
	function isType(Ctor, val) {
		return val !== undefined && val !== null && val.constructor === Ctor;
	}

	// Returns a safely quoted string
	function quoteStr(str) {
		return "'" +
		String(str)
		.replace(/\\/g, '\\\\')
		.replace(/'/g, "\\'")
		.replace(/\n/g, '\\n')
		.replace(/\r/g, '\\r')
		.replace(/\t/g, '\\t') +
		"'";
	}

	// Return an element from HTML
	function elementFromHtml(html) {
		var container = doc.createElement('_');
		container.innerHTML = html;
		return container.firstChild;
	}

	// Return HTML from an element
	function HtmlFromElement(el) {
		if (el.outerHTML) return el.outerHTML;
		var container = doc.createElement('_');
		container.appendChild(el.cloneNode(true));
		return container.innerHTML;
	}

	// Returns a string version of JavaScript
	function stringify(val) {
		var callee = arguments.callee, valArr = [], valLen, i = -1, e;
		// string
		if (isType(String, val)) return quoteStr(val);
		// boolean, function, number, regexp, undefined, null
		if (
			val === undefined ||
			val === null ||
			isType(Boolean, val) ||
			isType(Number, val) ||
			isType(RegExp, val) ||
			(isType(Function, val) && !/^function[^\{]+\{\s*\[native code\]/.test(String(val)))
		) return String(val);
		// date
		if (isType(Date, val)) {
			return 'new Date(' + val.getTime() + ')';
		}
		// array
		if (isType(Array, val)) {
			valLen = val.length;
			while (++i < valLen) valArr.push(callee(val[i]));
			return '[' + valArr + ']';
		}
		// object
		if (isType(Object, val)) {
			for (e in val) valArr.push(quoteStr(e) + ':' + callee(val[e]));
			return '{' + valArr + '}';
		}
		// native
		if (val === win) return 'window';
		for (e in win) if (val === win[e]) return 'window.'+e;
		for (e in doc) if (val === doc[e]) return 'document.'+e;
		// node
		if (val.nodeName) return 'h('+quoteStr(HtmlFromElement(val))+')';
	}

	// Returns a JavaScript version of a string
	function unstringify(str) {
		return new Function('var a=arguments;h=a[0];return ' + str).apply(win,[elementFromHtml]);
	}

	// Returns an extended object from arguments
	function extendObject() {
		var extObj = {}, arg = arguments, argLen = arg.length, i = -1, e;
		while (++i < argLen)
			if (isType(Object, arg[i]))
				for (e in arg[i])
					extObj[e] = isType(Object, extObj[e]) && isType(Object, arg[i][e]) ? arg.callee(extObj[e], arg[i][e]) : arg[i][e];
		return extObj;
	}

	// Writes to and extends local storage
	function setAndReturnIfValueChanged(attr, newValue, extend) {
		var rawValue = ls[attr], oldValue;
		if (extend) {
			oldValue = unstringify(rawValue);
			// if the existing item is an array
			if (isType(Array, oldValue)) newValue = oldValue.concat(newValue);
			// if the existing item is a boolean
			else if (isType(Boolean, oldValue)) newValue = oldValue && !!newValue;
			// if the existing item is a date and the new item can be a number
			else if (isType(Date, oldValue) && !isNaN(newValue * 1)) newValue = new Date(oldValue.getTime() + (newValue * 1));
			// if both the existing item and the new item are a function
			else if (isType(Function, oldValue) && isType(Function, newValue)) newValue = new Function('return(' + String(oldValue) + ').apply(this, arguments)&&(' + String(newValue) + ').apply(this, arguments)');
			// if the existing item is a number and the new item can be a number
			else if (isType(Number, oldValue) && !isNaN(newValue * 1)) newValue = oldValue + (newValue * 1);
			// if both the existing item and the new item are an object
			else if (isType(Object, oldValue) && isType(Object, newValue)) newValue = extendObject(oldValue, newValue);
			// if both the existing item and the new item are a regular expression
			else if (isType(RegExp, oldValue) && isType(RegExp, newValue)) {
				var
				regExpMatch = /^\/([\W\w]*)\/([a-z]*?)$/,	
				regExpA = String(oldValue).match(regExpMatch),
				regExpB = String(newValue).match(regExpMatch);
				newValue = new RegExp(regExpA[1] + regExpB[1], regExpA[2] + regExpB[2]);
			}
			// if the existing item is a string
			else if (isType(String, oldValue)) newValue = oldValue + String(newValue);
			else return 2;
		}
		newValue = stringify(newValue);
		if (rawValue === newValue) return 2;
		return (ls[attr] = newValue) && 1;
	}

	// Stash
	win.stash = {
		// returns whether a storage item exists or not
		has: function () {
			var args = [].concat.apply([], arguments), arg, i = -1;
			//
			while ((arg = args[++i])) if (ls[arg] === undefined) return false;
			return true;
		},
		// returns a local storage item
		get: function (attr) {
			var args = [].concat.apply([], arguments), arg, i = -1, items = {};
			//
			if (args.length === 1) return unstringify(ls[attr]);
			while ((arg = args[++i])) items[arg] = unstringify(ls[arg]);
			return items;
		},
		// returns all local storage items
		getAll: function () {
			var e, items = {};
			for (e in ls) items[e] = ls[e];
			return items;
		},
		// sets a local storage item, returns 1 if item(s) changed and 2 if not
		set: function (attr, val) {
			var args = [].concat.apply([], arguments), arg, i = -1, e, returnValue = 2;
			//
			if (isType(String, attr)) return setAndReturnIfValueChanged(attr, val);
			//
			while ((arg = args[++i])) for (e in arg) returnValue = Math.min(returnValue, setAndReturnIfValueChanged(e, arg[e]));
			//
			return returnValue;
		},
		// adds to a local storage item, returns 1 if item(s) changed and 2 if not
		add: function (attr, val) {
			var args = [].concat.apply([], arguments), arg, i = -1, e, returnValue = 2;
			//
			if (isType(String, attr)) return setAndReturnIfValueChanged(attr, val, true);
			//
			while ((arg = args[++i])) for (e in arg) returnValue = Math.min(returnValue, setAndReturnIfValueChanged(e, arg[e], true));
			//
			return returnValue;
		},
		// removals a local storage item
		cut: function (attr) {
			var args = [].concat.apply([], arguments), arg, i = -1;
			//
			while ((arg = args[++i])) delete ls[arg];
			return true;
		},
		// removes all items from local storage
		cutAll: function () {
			for (var e in ls) delete ls[e];
			return true;
		}
	};
})(this, this.localStorage, document);