WB 2.11.0

/*

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"});