/*
Script: XHR.js
	Contains the basic XMLHttpRequest Class Wrapper.

License:
	MIT-style license.
*/

/*
Class: XHR
	Basic XMLHttpRequest Wrapper.

Arguments:
	options - an object with options names as keys. See options below.

Options:
	method - 'post' or 'get' - the protocol for the request; optional, defaults to 'post'.
	async - boolean: asynchronous option; true uses asynchronous requests. Defaults to true.
	encoding - the encoding, defaults to utf-8.
	autoCancel - cancels the already running request if another one is sent. defaults to false.
	headers - accepts an object, that will be set to request headers.
	
Events:
	onRequest - function to execute when the XHR request is fired.
	onSuccess - function to execute when the XHR request completes.
	onStateChange - function to execute when the state of the XMLHttpRequest changes.
	onFailure - function to execute when the state of the XMLHttpRequest changes.

Properties:
	running - true if the request is running.
	response - object, text and xml as keys. You can access this property in the onSuccess event.

Example:
	>var myXHR = new XHR({method: 'get'}).send('http://site.com/requestHandler.php', 'name=john&lastname=dorian');
*/

var XHR = new Class({

	options: {
		method: 'post',
		async: true,
		onRequest: Class.empty,
		onSuccess: Class.empty,
		onFailure: Class.empty,
		urlEncoded: true,
		encoding: 'utf-8',
		autoCancel: false,
		headers: {}
	},

	setTransport: function(){
		this.transport = (window.XMLHttpRequest) ? new XMLHttpRequest() : (window.ie ? new ActiveXObject('Microsoft.XMLHTTP') : false);
		return this;
	},

	initialize: function(options){
		this.setTransport().setOptions(options);
		this.options.isSuccess = this.options.isSuccess || this.isSuccess;
		this.headers = {};
		if (this.options.urlEncoded && this.options.method == 'post'){
			var encoding = (this.options.encoding) ? '; charset=' + this.options.encoding : '';
			this.setHeader('Content-type', 'application/x-www-form-urlencoded' + encoding);
		}
		if (this.options.initialize) this.options.initialize.call(this);
	},

	onStateChange: function(){
		if (this.transport.readyState != 4 || !this.running) return;
		this.running = false;
		var status = 0;
		try {status = this.transport.status;} catch(e){};
		if (this.options.isSuccess.call(this, status)) this.onSuccess();
		else this.onFailure();
		this.transport.onreadystatechange = Class.empty;
	},

	isSuccess: function(status){
		return ((status >= 200) && (status < 300));
	},

	onSuccess: function(){
		this.response = {
			'text': this.transport.responseText,
			'xml': this.transport.responseXML
		};
		this.fireEvent('onSuccess', [this.response.text, this.response.xml]);
		this.callChain();
	},

	onFailure: function(){
		this.fireEvent('onFailure', this.transport);
	},

	/*
	Property: setHeader
		Add/modify an header for the request. It will not override headers from the options.

	Example:
		>var myXhr = new XHR(url, {method: 'get', headers: {'X-Request': 'JSON'}});
		>myXhr.setHeader('Last-Modified','Sat, 1 Jan 2005 05:00:00 GMT');
	*/

	setHeader: function(name, value){
		this.headers[name] = value;
		return this;
	},

	/*
	Property: send
		Opens the XHR connection and sends the data. Data has to be null or a string.

	Example:
		>var myXhr = new XHR({method: 'post'});
		>myXhr.send(url, querystring);
		>
		>var syncXhr = new XHR({async: false, method: 'post'});
		>syncXhr.send(url, null);
		>
	*/

	send: function(url, data){
		if (this.options.autoCancel) this.cancel();
		else if (this.running) return this;
		this.running = true;
		if (data && this.options.method == 'get'){
			url = url + (url.contains('?') ? '&' : '?') + data;
			data = null;
		}
		this.transport.open(this.options.method.toUpperCase(), url, this.options.async);
		this.transport.onreadystatechange = this.onStateChange.bind(this);
		if ((this.options.method == 'post') && this.transport.overrideMimeType) this.setHeader('Connection', 'close');
		$extend(this.headers, this.options.headers);
		for (var type in this.headers) try {this.transport.setRequestHeader(type, this.headers[type]);} catch(e){};
		this.fireEvent('onRequest');
		this.transport.send($pick(data, null));
		return this;
	},

	/*
	Property: cancel
		Cancels the running request. No effect if the request is not running.

	Example:
		>var myXhr = new XHR({method: 'get'}).send(url);
		>myXhr.cancel();
	*/

	cancel: function(){
		if (!this.running) return this;
		this.running = false;
		this.transport.abort();
		this.transport.onreadystatechange = Class.empty;
		this.setTransport();
		this.fireEvent('onCancel');
		return this;
	}

});

XHR.implement(new Chain, new Events, new Options);

/*
Script: Ajax.js
	Contains the <Ajax> class. Also contains methods to generate querystings from forms and Objects.

Credits:
	Loosely based on the version from prototype.js <http://prototype.conio.net>

License:
	MIT-style license.
*/

/*
Class: Ajax
	An Ajax class, For all your asynchronous needs.
	Inherits methods, properties, options and events from <XHR>.

Arguments:
	url - the url pointing to the server-side script.
	options - optional, an object containing options.

Options:
	data - you can write parameters here. Can be a querystring, an object or a Form element.
	update - $(element) to insert the response text of the XHR into, upon completion of the request.
	evalScripts - boolean; default is false. Execute scripts in the response text onComplete. When the response is javascript the whole response is evaluated.
	evalResponse - boolean; default is false. Force global evalulation of the whole response, no matter what content-type it is.
	
Events:
	onComplete - function to execute when the ajax request completes.

Example:
	>var myAjax = new Ajax(url, {method: 'get'}).request();
*/

var Ajax = XHR.extend({

	options: {
		data: null,
		update: null,
		onComplete: Class.empty,
		evalScripts: false,
		evalResponse: false
	},

	initialize: function(url, options){
		this.addEvent('onSuccess', this.onComplete);
		this.setOptions(options);
		/*compatibility*/
		this.options.data = this.options.data || this.options.postBody;
		/*end compatibility*/
		if (!['post', 'get'].contains(this.options.method)){
			this._method = '_method=' + this.options.method;
			this.options.method = 'post';
		}
		this.parent();
		this.setHeader('X-Requested-With', 'XMLHttpRequest');
		this.setHeader('Accept', 'text/javascript, text/html, application/xml, text/xml, */*');
		this.url = url;
	},

	onComplete: function(){
		if (this.options.update) $(this.options.update).empty().setHTML(this.response.text);
		if (this.options.evalScripts || this.options.evalResponse) this.evalScripts();
		this.fireEvent('onComplete', [this.response.text, this.response.xml], 20);
	},

	/*
	Property: request
		Executes the ajax request.

	Example:
		>var myAjax = new Ajax(url, {method: 'get'});
		>myAjax.request();

		OR

		>new Ajax(url, {method: 'get'}).request();
	*/

	request: function(data){
		data = data || this.options.data;
		switch($type(data)){
			case 'element': data = $(data).toQueryString(); break;
			case 'object': data = Object.toQueryString(data);
		}
		if (this._method) data = (data) ? [this._method, data].join('&') : this._method;
		return this.send(this.url, data);
	},

	/*
	Property: evalScripts
		Executes scripts in the response text
	*/

	evalScripts: function(){
		var script, scripts;
		if (this.options.evalResponse || (/(ecma|java)script/).test(this.getHeader('Content-type'))) scripts = this.response.text;
		else {
			scripts = [];
			var regexp = /<script[^>]*>([\s\S]*?)<\/script>/gi;
			while ((script = regexp.exec(this.response.text))) scripts.push(script[1]);
			scripts = scripts.join('\n');
		}
		if (scripts) (window.execScript) ? window.execScript(scripts) : window.setTimeout(scripts, 0);
	},

	/*
	Property: getHeader
		Returns the given response header or null
	*/

	getHeader: function(name){
		try {return this.transport.getResponseHeader(name);} catch(e){};
		return null;
	}

});

/* Section: Object related Functions */

/*
Function: Object.toQueryString
	Generates a querystring from key/pair values in an object

Arguments:
	source - the object to generate the querystring from.

Returns:
	the query string.

Example:
	>Object.toQueryString({apple: "red", lemon: "yellow"}); //returns "apple=red&lemon=yellow"
*/

Object.toQueryString = function(source){
	var queryString = [];
	for (var property in source) queryString.push(encodeURIComponent(property) + '=' + encodeURIComponent(source[property]));
	return queryString.join('&');
};

/*
Class: Element
	Custom class to allow all of its methods to be used with any DOM element via the dollar function <$>.
*/

Element.extend({

	/*
	Property: send
		Sends a form with an ajax post request

	Arguments:
		options - option collection for ajax request. See <Ajax> for the options list.

	Returns:
		The Ajax Class Instance

	Example:
		(start code)
		<form id="myForm" action="submit.php">
		<input name="email" value="bob@bob.com">
		<input name="zipCode" value="90210">
		</form>
		<script>
		$('myForm').send()
		</script>
		(end)
	*/

	send: function(options){
		return new Ajax(this.getProperty('action'), $merge({data: this.toQueryString()}, options, {method: 'post'})).request();
	}

});