WB 2.08.x

/*

Copyright (c) 2009, Yahoo! Inc. All rights reserved.

Code licensed under the BSD License:

http://developer.yahoo.net/yui/license.txt

version: 2.8.0r4

*/

/**

 * The Connection Manager provides a simplified interface to the XMLHttpRequest

 * object.  It handles cross-browser instantiantion of XMLHttpRequest, negotiates the

 * interactive states and server response, returning the results to a pre-defined

 * callback you create.

 *

 * @namespace YAHOO.util

 * @module connection

 * @requires yahoo

 * @requires event

 */

/**

 * The Connection Manager singleton provides methods for creating and managing

 * asynchronous transactions.

 *

 * @class Connect

 */

YAHOO.util.Connect =

{

  /**

   * @description Array of MSFT ActiveX ids for XMLHttpRequest.

   * @property _msxml_progid

   * @private

   * @static

   * @type array

   */

	_msxml_progid:[

		'Microsoft.XMLHTTP',

		'MSXML2.XMLHTTP.3.0',

		'MSXML2.XMLHTTP'

		],

  /**

   * @description Object literal of HTTP header(s)

   * @property _http_header

   * @private

   * @static

   * @type object

   */

	_http_headers:{},

  /**

   * @description Determines if HTTP headers are set.

   * @property _has_http_headers

   * @private

   * @static

   * @type boolean

   */

	_has_http_headers:false,

 /**

  * @description Determines if a default header of

  * Content-Type of 'application/x-www-form-urlencoded'

  * will be added to any client HTTP headers sent for POST

  * transactions.

  * @property _use_default_post_header

  * @private

  * @static

  * @type boolean

  */

    _use_default_post_header:true,

 /**

  * @description The default header used for POST transactions.

  * @property _default_post_header

  * @private

  * @static

  * @type boolean

  */

    _default_post_header:'application/x-www-form-urlencoded; charset=UTF-8',

 /**

  * @description The default header used for transactions involving the

  * use of HTML forms.

  * @property _default_form_header

  * @private

  * @static

  * @type boolean

  */

    _default_form_header:'application/x-www-form-urlencoded',

 /**

  * @description Determines if a default header of

  * 'X-Requested-With: XMLHttpRequest'

  * will be added to each transaction.

  * @property _use_default_xhr_header

  * @private

  * @static

  * @type boolean

  */

    _use_default_xhr_header:true,

 /**

  * @description The default header value for the label

  * "X-Requested-With".  This is sent with each

  * transaction, by default, to identify the

  * request as being made by YUI Connection Manager.

  * @property _default_xhr_header

  * @private

  * @static

  * @type boolean

  */

    _default_xhr_header:'XMLHttpRequest',

 /**

  * @description Determines if custom, default headers

  * are set for each transaction.

  * @property _has_default_header

  * @private

  * @static

  * @type boolean

  */

    _has_default_headers:true,

 /**

  * @description Determines if custom, default headers

  * are set for each transaction.

  * @property _has_default_header

  * @private

  * @static

  * @type boolean

  */

    _default_headers:{},

 /**

  * @description Collection of polling references to the polling mechanism in handleReadyState.

  * @property _poll

  * @private

  * @static

  * @type object

  */

    _poll:{},

 /**

  * @description Queue of timeout values for each transaction callback with a defined timeout value.

  * @property _timeOut

  * @private

  * @static

  * @type object

  */

    _timeOut:{},

  /**

   * @description The polling frequency, in milliseconds, for HandleReadyState.

   * when attempting to determine a transaction's XHR readyState.

   * The default is 50 milliseconds.

   * @property _polling_interval

   * @private

   * @static

   * @type int

   */

     _polling_interval:50,

  /**

   * @description A transaction counter that increments the transaction id for each transaction.

   * @property _transaction_id

   * @private

   * @static

   * @type int

   */

     _transaction_id:0,

  /**

   * @description Custom event that fires at the start of a transaction

   * @property startEvent

   * @private

   * @static

   * @type CustomEvent

   */

	startEvent: new YAHOO.util.CustomEvent('start'),

  /**

   * @description Custom event that fires when a transaction response has completed.

   * @property completeEvent

   * @private

   * @static

   * @type CustomEvent

   */

	completeEvent: new YAHOO.util.CustomEvent('complete'),

  /**

   * @description Custom event that fires when handleTransactionResponse() determines a

   * response in the HTTP 2xx range.

   * @property successEvent

   * @private

   * @static

   * @type CustomEvent

   */

	successEvent: new YAHOO.util.CustomEvent('success'),

  /**

   * @description Custom event that fires when handleTransactionResponse() determines a

   * response in the HTTP 4xx/5xx range.

   * @property failureEvent

   * @private

   * @static

   * @type CustomEvent

   */

	failureEvent: new YAHOO.util.CustomEvent('failure'),

  /**

   * @description Custom event that fires when a transaction is successfully aborted.

   * @property abortEvent

   * @private

   * @static

   * @type CustomEvent

   */

	abortEvent: new YAHOO.util.CustomEvent('abort'),

  /**

   * @description A reference table that maps callback custom events members to its specific

   * event name.

   * @property _customEvents

   * @private

   * @static

   * @type object

   */

	_customEvents:

	{

		onStart:['startEvent', 'start'],

		onComplete:['completeEvent', 'complete'],

		onSuccess:['successEvent', 'success'],

		onFailure:['failureEvent', 'failure'],

		onUpload:['uploadEvent', 'upload'],

		onAbort:['abortEvent', 'abort']

	},

  /**

   * @description Member to add an ActiveX id to the existing xml_progid array.

   * In the event(unlikely) a new ActiveX id is introduced, it can be added

   * without internal code modifications.

   * @method setProgId

   * @public

   * @static

   * @param {string} id The ActiveX id to be added to initialize the XHR object.

   * @return void

   */

	setProgId:function(id)

	{

		this._msxml_progid.unshift(id);

	},

  /**

   * @description Member to override the default POST header.

   * @method setDefaultPostHeader

   * @public

   * @static

   * @param {boolean} b Set and use default header - true or false .

   * @return void

   */

	setDefaultPostHeader:function(b)

	{

		if(typeof b == 'string'){

			this._default_post_header = b;

		}

		else if(typeof b == 'boolean'){

			this._use_default_post_header = b;

		}

	},

  /**

   * @description Member to override the default transaction header..

   * @method setDefaultXhrHeader

   * @public

   * @static

   * @param {boolean} b Set and use default header - true or false .

   * @return void

   */

	setDefaultXhrHeader:function(b)

	{

		if(typeof b == 'string'){

			this._default_xhr_header = b;

		}

		else{

			this._use_default_xhr_header = b;

		}

	},

  /**

   * @description Member to modify the default polling interval.

   * @method setPollingInterval

   * @public

   * @static

   * @param {int} i The polling interval in milliseconds.

   * @return void

   */

	setPollingInterval:function(i)

	{

		if(typeof i == 'number' && isFinite(i)){

			this._polling_interval = i;

		}

	},

  /**

   * @description Instantiates a XMLHttpRequest object and returns an object with two properties:

   * the XMLHttpRequest instance and the transaction id.

   * @method createXhrObject

   * @private

   * @static

   * @param {int} transactionId Property containing the transaction id for this transaction.

   * @return object

   */

	createXhrObject:function(transactionId)

	{

		var obj,http,i;

		try

		{

			// Instantiates XMLHttpRequest in non-IE browsers and assigns to http.

			http = new XMLHttpRequest();

			//  Object literal with http and tId properties

			obj = { conn:http, tId:transactionId, xhr: true };

		}

		catch(e)

		{

			for(i=0; i<this._msxml_progid.length; ++i){

				try

				{

					// Instantiates XMLHttpRequest for IE and assign to http

					http = new ActiveXObject(this._msxml_progid[i]);

					//  Object literal with conn and tId properties

					obj = { conn:http, tId:transactionId, xhr: true };

					break;

				}

				catch(e1){}

			}

		}

		finally

		{

			return obj;

		}

	},

  /**

   * @description This method is called by asyncRequest to create a

   * valid connection object for the transaction.  It also passes a

   * transaction id and increments the transaction id counter.

   * @method getConnectionObject

   * @private

   * @static

   * @return {object}

   */

	getConnectionObject:function(t)

	{

		var o, tId = this._transaction_id;

		try

		{

			if(!t){

				o = this.createXhrObject(tId);

			}

			else{

				o = {tId:tId};

				if(t==='xdr'){

					o.conn = this._transport;

					o.xdr = true;

				}

				else if(t==='upload'){

					o.upload = true;

				}

			}

			if(o){

				this._transaction_id++;

			}

		}

		catch(e){}

		return o;

	},

  /**

   * @description Method for initiating an asynchronous request via the XHR object.

   * @method asyncRequest

   * @public

   * @static

   * @param {string} method HTTP transaction method

   * @param {string} uri Fully qualified path of resource

   * @param {callback} callback User-defined callback function or object

   * @param {string} postData POST body

   * @return {object} Returns the connection object

   */

	asyncRequest:function(method, uri, callback, postData)

	{

		var o,t,args = (callback && callback.argument)?callback.argument:null;

		if(this._isFileUpload){

			t = 'upload';

		}

		else if(callback.xdr){

			t = 'xdr';

		}

		o = this.getConnectionObject(t);

		if(!o){

			return null;

		}

		else{

			// Intialize any transaction-specific custom events, if provided.

			if(callback && callback.customevents){

				this.initCustomEvents(o, callback);

			}

			if(this._isFormSubmit){

				if(this._isFileUpload){

					this.uploadFile(o, callback, uri, postData);

					return o;

				}

				// If the specified HTTP method is GET, setForm() will return an

				// encoded string that is concatenated to the uri to

				// create a querystring.

				if(method.toUpperCase() == 'GET'){

					if(this._sFormData.length !== 0){

						// If the URI already contains a querystring, append an ampersand

						// and then concatenate _sFormData to the URI.

						uri += ((uri.indexOf('?') == -1)?'?':'&') + this._sFormData;

					}

				}

				else if(method.toUpperCase() == 'POST'){

					// If POST data exist in addition to the HTML form data,

					// it will be concatenated to the form data.

					postData = postData?this._sFormData + "&" + postData:this._sFormData;

				}

			}

			if(method.toUpperCase() == 'GET' && (callback && callback.cache === false)){

				// If callback.cache is defined and set to false, a

				// timestamp value will be added to the querystring.

				uri += ((uri.indexOf('?') == -1)?'?':'&') + "rnd=" + new Date().valueOf().toString();

			}

			// Each transaction will automatically include a custom header of

			// "X-Requested-With: XMLHttpRequest" to identify the request as

			// having originated from Connection Manager.

			if(this._use_default_xhr_header){

				if(!this._default_headers['X-Requested-With']){

					this.initHeader('X-Requested-With', this._default_xhr_header, true);

				}

			}

			//If the transaction method is POST and the POST header value is set to true

			//or a custom value, initalize the Content-Type header to this value.

			if((method.toUpperCase() === 'POST' && this._use_default_post_header) && this._isFormSubmit === false){

				this.initHeader('Content-Type', this._default_post_header);

			}

			if(o.xdr){

				this.xdr(o, method, uri, callback, postData);

				return o;

			}

			o.conn.open(method, uri, true);

			//Initialize all default and custom HTTP headers,

			if(this._has_default_headers || this._has_http_headers){

				this.setHeader(o);

			}

			this.handleReadyState(o, callback);

			o.conn.send(postData || '');

			// Reset the HTML form data and state properties as

			// soon as the data are submitted.

			if(this._isFormSubmit === true){

				this.resetFormState();

			}

			// Fire global custom event -- startEvent

			this.startEvent.fire(o, args);

			if(o.startEvent){

				// Fire transaction custom event -- startEvent

				o.startEvent.fire(o, args);

			}

			return o;

		}

	},

  /**

   * @description This method creates and subscribes custom events,

   * specific to each transaction

   * @method initCustomEvents

   * @private

   * @static

   * @param {object} o The connection object

   * @param {callback} callback The user-defined callback object

   * @return {void}

   */

	initCustomEvents:function(o, callback)

	{

		var prop;

		// Enumerate through callback.customevents members and bind/subscribe

		// events that match in the _customEvents table.

		for(prop in callback.customevents){

			if(this._customEvents[prop][0]){

				// Create the custom event

				o[this._customEvents[prop][0]] = new YAHOO.util.CustomEvent(this._customEvents[prop][1], (callback.scope)?callback.scope:null);

				// Subscribe the custom event

				o[this._customEvents[prop][0]].subscribe(callback.customevents[prop]);

			}

		}

	},

  /**

   * @description This method serves as a timer that polls the XHR object's readyState

   * property during a transaction, instead of binding a callback to the

   * onreadystatechange event.  Upon readyState 4, handleTransactionResponse

   * will process the response, and the timer will be cleared.

   * @method handleReadyState

   * @private

   * @static

   * @param {object} o The connection object

   * @param {callback} callback The user-defined callback object

   * @return {void}

   */

    handleReadyState:function(o, callback)

    {

		var oConn = this,

			args = (callback && callback.argument)?callback.argument:null;

		if(callback && callback.timeout){

			this._timeOut[o.tId] = window.setTimeout(function(){ oConn.abort(o, callback, true); }, callback.timeout);

		}

		this._poll[o.tId] = window.setInterval(

			function(){

				if(o.conn && o.conn.readyState === 4){

					// Clear the polling interval for the transaction

					// and remove the reference from _poll.

					window.clearInterval(oConn._poll[o.tId]);

					delete oConn._poll[o.tId];

					if(callback && callback.timeout){

						window.clearTimeout(oConn._timeOut[o.tId]);

						delete oConn._timeOut[o.tId];

					}

					// Fire global custom event -- completeEvent

					oConn.completeEvent.fire(o, args);

					if(o.completeEvent){

						// Fire transaction custom event -- completeEvent

						o.completeEvent.fire(o, args);

					}

					oConn.handleTransactionResponse(o, callback);

				}

			}

		,this._polling_interval);

    },

  /**

   * @description This method attempts to interpret the server response and

   * determine whether the transaction was successful, or if an error or

   * exception was encountered.

   * @method handleTransactionResponse

   * @private

   * @static

   * @param {object} o The connection object

   * @param {object} callback The user-defined callback object

   * @param {boolean} isAbort Determines if the transaction was terminated via abort().

   * @return {void}

   */

    handleTransactionResponse:function(o, callback, isAbort)

    {

		var httpStatus, responseObject,

			args = (callback && callback.argument)?callback.argument:null,

			xdrS = (o.r && o.r.statusText === 'xdr:success')?true:false,

			xdrF = (o.r && o.r.statusText === 'xdr:failure')?true:false,

			xdrA = isAbort;

		try

		{

			if((o.conn.status !== undefined && o.conn.status !== 0) || xdrS){

				// XDR requests will not have HTTP status defined. The

				// statusText property will define the response status

				// set by the Flash transport.

				httpStatus = o.conn.status;

			}

			else if(xdrF && !xdrA){

				// Set XDR transaction failure to a status of 0, which

				// resolves as an HTTP failure, instead of an exception.

				httpStatus = 0;

			}

			else{

				httpStatus = 13030;

			}

		}

		catch(e){

			 // 13030 is a custom code to indicate the condition -- in Mozilla/FF --

			 // when the XHR object's status and statusText properties are

			 // unavailable, and a query attempt throws an exception.

			httpStatus = 13030;

		}

		if((httpStatus >= 200 && httpStatus < 300) || httpStatus === 1223 || xdrS){

			responseObject = o.xdr ? o.r : this.createResponseObject(o, args);

			if(callback && callback.success){

				if(!callback.scope){

					callback.success(responseObject);

				}

				else{

					// If a scope property is defined, the callback will be fired from

					// the context of the object.

					callback.success.apply(callback.scope, [responseObject]);

				}

			}

			// Fire global custom event -- successEvent

			this.successEvent.fire(responseObject);

			if(o.successEvent){

				// Fire transaction custom event -- successEvent

				o.successEvent.fire(responseObject);

			}

		}

		else{

			switch(httpStatus){

				// The following cases are wininet.dll error codes that may be encountered.

				case 12002: // Server timeout

				case 12029: // 12029 to 12031 correspond to dropped connections.

				case 12030:

				case 12031:

				case 12152: // Connection closed by server.

				case 13030: // See above comments for variable status.

					// XDR transactions will not resolve to this case, since the

					// response object is already built in the xdr response.

					responseObject = this.createExceptionObject(o.tId, args, (isAbort?isAbort:false));

					if(callback && callback.failure){

						if(!callback.scope){

							callback.failure(responseObject);

						}

						else{

							callback.failure.apply(callback.scope, [responseObject]);

						}

					}

					break;

				default:

					responseObject = (o.xdr) ? o.response : this.createResponseObject(o, args);

					if(callback && callback.failure){

						if(!callback.scope){

							callback.failure(responseObject);

						}

						else{

							callback.failure.apply(callback.scope, [responseObject]);

						}

					}

			}

			// Fire global custom event -- failureEvent

			this.failureEvent.fire(responseObject);

			if(o.failureEvent){

				// Fire transaction custom event -- failureEvent

				o.failureEvent.fire(responseObject);

			}

		}

		this.releaseObject(o);

		responseObject = null;

    },

  /**

   * @description This method evaluates the server response, creates and returns the results via

   * its properties.  Success and failure cases will differ in the response

   * object's property values.

   * @method createResponseObject

   * @private

   * @static

   * @param {object} o The connection object

   * @param {callbackArg} callbackArg The user-defined argument or arguments to be passed to the callback

   * @return {object}

   */

    createResponseObject:function(o, callbackArg)

    {

		var obj = {}, headerObj = {},

			i, headerStr, header, delimitPos;

		try

		{

			headerStr = o.conn.getAllResponseHeaders();

			header = headerStr.split('\n');

			for(i=0; i<header.length; i++){

				delimitPos = header[i].indexOf(':');

				if(delimitPos != -1){

					headerObj[header[i].substring(0,delimitPos)] = YAHOO.lang.trim(header[i].substring(delimitPos+2));

				}

			}

		}

		catch(e){}

		obj.tId = o.tId;

		// Normalize IE's response to HTTP 204 when Win error 1223.

		obj.status = (o.conn.status == 1223)?204:o.conn.status;

		// Normalize IE's statusText to "No Content" instead of "Unknown".

		obj.statusText = (o.conn.status == 1223)?"No Content":o.conn.statusText;

		obj.getResponseHeader = headerObj;

		obj.getAllResponseHeaders = headerStr;

		obj.responseText = o.conn.responseText;

		obj.responseXML = o.conn.responseXML;

		if(callbackArg){

			obj.argument = callbackArg;

		}

		return obj;

    },

  /**

   * @description If a transaction cannot be completed due to dropped or closed connections,

   * there may be not be enough information to build a full response object.

   * The failure callback will be fired and this specific condition can be identified

   * by a status property value of 0.

   *

   * If an abort was successful, the status property will report a value of -1.

   *

   * @method createExceptionObject

   * @private

   * @static

   * @param {int} tId The Transaction Id

   * @param {callbackArg} callbackArg The user-defined argument or arguments to be passed to the callback

   * @param {boolean} isAbort Determines if the exception case is caused by a transaction abort

   * @return {object}

   */

    createExceptionObject:function(tId, callbackArg, isAbort)

    {

		var COMM_CODE = 0,

			COMM_ERROR = 'communication failure',

			ABORT_CODE = -1,

			ABORT_ERROR = 'transaction aborted',

			obj = {};

		obj.tId = tId;

		if(isAbort){

			obj.status = ABORT_CODE;

			obj.statusText = ABORT_ERROR;

		}

		else{

			obj.status = COMM_CODE;

			obj.statusText = COMM_ERROR;

		}

		if(callbackArg){

			obj.argument = callbackArg;

		}

		return obj;

    },

  /**

   * @description Method that initializes the custom HTTP headers for the each transaction.

   * @method initHeader

   * @public

   * @static

   * @param {string} label The HTTP header label

   * @param {string} value The HTTP header value

   * @param {string} isDefault Determines if the specific header is a default header

   * automatically sent with each transaction.

   * @return {void}

   */

	initHeader:function(label, value, isDefault)

	{

		var headerObj = (isDefault)?this._default_headers:this._http_headers;

		headerObj[label] = value;

		if(isDefault){

			this._has_default_headers = true;

		}

		else{

			this._has_http_headers = true;

		}

	},

  /**

   * @description Accessor that sets the HTTP headers for each transaction.

   * @method setHeader

   * @private

   * @static

   * @param {object} o The connection object for the transaction.

   * @return {void}

   */

	setHeader:function(o)

	{

		var prop;

		if(this._has_default_headers){

			for(prop in this._default_headers){

				if(YAHOO.lang.hasOwnProperty(this._default_headers, prop)){

					o.conn.setRequestHeader(prop, this._default_headers[prop]);

				}

			}

		}

		if(this._has_http_headers){

			for(prop in this._http_headers){

				if(YAHOO.lang.hasOwnProperty(this._http_headers, prop)){

					o.conn.setRequestHeader(prop, this._http_headers[prop]);

				}

			}

			this._http_headers = {};

			this._has_http_headers = false;

		}

	},

  /**

   * @description Resets the default HTTP headers object

   * @method resetDefaultHeaders

   * @public

   * @static

   * @return {void}

   */

	resetDefaultHeaders:function(){

		this._default_headers = {};

		this._has_default_headers = false;

	},

  /**

   * @description Method to terminate a transaction, if it has not reached readyState 4.

   * @method abort

   * @public

   * @static

   * @param {object} o The connection object returned by asyncRequest.

   * @param {object} callback  User-defined callback object.

   * @param {string} isTimeout boolean to indicate if abort resulted from a callback timeout.

   * @return {boolean}

   */

	abort:function(o, callback, isTimeout)

	{

		var abortStatus,

			args = (callback && callback.argument)?callback.argument:null;

			o = o || {};

		if(o.conn){

			if(o.xhr){

				if(this.isCallInProgress(o)){

					// Issue abort request

					o.conn.abort();

					window.clearInterval(this._poll[o.tId]);

					delete this._poll[o.tId];

					if(isTimeout){

						window.clearTimeout(this._timeOut[o.tId]);

						delete this._timeOut[o.tId];

					}

					abortStatus = true;

				}

			}

			else if(o.xdr){

				o.conn.abort(o.tId);

				abortStatus = true;

			}

		}

		else if(o.upload){

			var frameId = 'yuiIO' + o.tId;

			var io = document.getElementById(frameId);

			if(io){

				// Remove all listeners on the iframe prior to

				// its destruction.

				YAHOO.util.Event.removeListener(io, "load");

				// Destroy the iframe facilitating the transaction.

				document.body.removeChild(io);

				if(isTimeout){

					window.clearTimeout(this._timeOut[o.tId]);

					delete this._timeOut[o.tId];

				}

				abortStatus = true;

			}

		}

		else{

			abortStatus = false;

		}

		if(abortStatus === true){

			// Fire global custom event -- abortEvent

			this.abortEvent.fire(o, args);

			if(o.abortEvent){

				// Fire transaction custom event -- abortEvent

				o.abortEvent.fire(o, args);

			}

			this.handleTransactionResponse(o, callback, true);

		}

		return abortStatus;

	},

  /**

   * @description Determines if the transaction is still being processed.

   * @method isCallInProgress

   * @public

   * @static

   * @param {object} o The connection object returned by asyncRequest

   * @return {boolean}

   */

	isCallInProgress:function(o)

	{

		o = o || {};

		// if the XHR object assigned to the transaction has not been dereferenced,

		// then check its readyState status.  Otherwise, return false.

		if(o.xhr && o.conn){

			return o.conn.readyState !== 4 && o.conn.readyState !== 0;

		}

		else if(o.xdr && o.conn){

			return o.conn.isCallInProgress(o.tId);

		}

		else if(o.upload === true){

			return document.getElementById('yuiIO' + o.tId)?true:false;

		}

		else{

			return false;

		}

	},

  /**

   * @description Dereference the XHR instance and the connection object after the transaction is completed.

   * @method releaseObject

   * @private

   * @static

   * @param {object} o The connection object

   * @return {void}

   */

	releaseObject:function(o)

	{

		if(o && o.conn){

			//dereference the XHR instance.

			o.conn = null;

			//dereference the connection object.

			o = null;

		}

	}

};

YAHOO.register("connection_core", YAHOO.util.Connect, {version: "2.8.0r4", build: "2449"});