
/*

  SmartClient Ajax RIA system
  Version v9.0p_2021-05-01/LGPL Deployment (2021-05-01)

  Copyright 2000 and beyond Isomorphic Software, Inc. All rights reserved.
  "SmartClient" is a trademark of Isomorphic Software, Inc.

  LICENSE NOTICE
     INSTALLATION OR USE OF THIS SOFTWARE INDICATES YOUR ACCEPTANCE OF
     ISOMORPHIC SOFTWARE LICENSE TERMS. If you have received this file
     without an accompanying Isomorphic Software license file, please
     contact licensing@isomorphic.com for details. Unauthorized copying and
     use of this software is a violation of international copyright law.

  DEVELOPMENT ONLY - DO NOT DEPLOY
     This software is provided for evaluation, training, and development
     purposes only. It may include supplementary components that are not
     licensed for deployment. The separate DEPLOY package for this release
     contains SmartClient components that are licensed for deployment.

  PROPRIETARY & PROTECTED MATERIAL
     This software contains proprietary materials that are protected by
     contract and intellectual property law. You are expressly prohibited
     from attempting to reverse engineer this software or modify this
     software for human readability.

  CONTACT ISOMORPHIC
     For more information regarding license rights and restrictions, or to
     report possible license violations, please contact Isomorphic Software
     by email (licensing@isomorphic.com) or web (www.isomorphic.com).

*/
//>	@class Comm
// Provide background communication with an HTTP server
//<

// create the Comm singleton object
isc.ClassFactory.defineClass("Comm");

// add properties to the Comm object
isc.Comm.addClassProperties( {

    //>	@classAttr	isc.Comm.sendMethod (string : isc.Comm.sendMethod : I)
	//			communication method
	//		@group	communication
	//<
	sendMethod:	"POST",

	//>	@type	SendMethod
	//			@visibility external
	//			@group	communication
	// @value	"GET"     GET method (regular URL encoding)		
	// @value	"POST"    POST method (form field encoding)
	//<

	// Sequence number for forms created in IE to send data to the server.  Used to give each
    // form a unique name.
	_generatedFormNumber : 0

});


isc.Comm.addClassMethods({

// XMLHttpRequest vs IFrame Comm
//
// Advantages:
// - doesn't add to history in older Moz
// - no request for empty.html in HTTPS
// - doesn't add to document.frames and potentially screw up numbering
// - ability to detect load with a server-initiated callback
// - synchronous option
//
// Disadvantages / neutral
// - can't handle upload fields
// - is subject to concurrent requests limit in IE (test by adding Thread.sleep(5000) to
//   IDACall - responses come in closely-spaced pairs)
// - no persistent connections in IE (server push), see:
//    http://jszen.blogspot.com/2005/03/xmlhttp-and-readystate.html
// - no compression in IE 5.5
//
// XMLHttpRequest behavior with file:// URL - works on FF, Safari, and IE but on all these
// platforms the URL must be relative or it doesn't work.  SO e.g. ../foo.html is ok, but
// /foo.html is not.  Haven't tested specifying the full path (e.g. c:\foo\bar.html).  
//
// For XMLHttpRequest, FF uses the baseURL of the window object that started thread that
// eventually calls XMLHttpRequest.send() as the baseURL for resolving the relative reference.
// This means that if you send an RPC using XMLHttpRequest out of the eval area of the
// Developer Console, your base URL will be /isomorphic/system/helpers - because that's where
// Log.html came from.  You can use a timeout to restart the thread in the appropriate context
// - just be aware of this oddity.

_fireXMLCallback : function (request, callback, delayedCall) {
    

    if (!delayedCall) isc.EH._setThread("XRP");

    // NOTE: last param tells fireCalllback to trap errors in Moz
    isc.Class.fireCallback(callback, "xmlHttpRequest", [request], null, true);

    if (!delayedCall) isc.EH._clearThread();
},

// ==========================================================================================
// IMPORTANT: If you update the XMLHttp code here, also update FileLoader.js
// ==========================================================================================
_getStateChangeHandler : function () {
    return function () {
        var request = arguments.callee.request;
 
        // IE 5.5 manages to call this handler after readyState changes to 4 and we process the
        // request, which would cause the whole RPC reply logic to run more than once which
        // breaks badly.  If we run more than once, the request will be null becase we null it out
        // below, so just trap this case and return.
        if (!request) return;
        
        if (request.readyState != 4) return;

        arguments.callee.request = null;

        // Bizarre IE-only bug: in the middle of a readyStateChange thread, we draw a
        // new widget, and on touching the newly created handle in
        // Canvas._browserDoneDrawing(), IE decides it's a good time to interrupt the current
        // thread and fire readyStateChange from another xmlHttpRequest that has arrived in the
        // meantime - this can actually be seen in the stack trace, which shows this handler
        // being called (impossibly) by _browserDoneDrawing().  
        // So far as we know, IE is not willing to similarly interrupt a timer thread, so we
        // fire the callback on a 0ms timer instead, which should be order-preserving.
        // NOTE: do not use a closure here or a leak will be introduced
        //isc.Comm._fireXMLCallback(request, arguments.callee.callback);
        isc.Timer.setTimeout({ target:isc.Comm, methodName:"_fireXMLCallback",
                               args:[request, arguments.callee.callback, true] }, 0);
    }
},


// Upon shipping XML3.0, Microsoft started installing XML parsers in "side by side mode"
// meaning the previous version is left intact and a new version is installed parallel to
// the existing one.  Prior to this the latest XML parser being installed by some piece of
// software would overwrite the previous verison and potentially break the software that
// depended on that version.  The catch is that to get the later versions of the parser, you
// need to specify a version-specific prefix.
//
// We use a version independent prefix to get the 2.0 parser in IE6.0 and IE5.5 and then
// fall back on version-specific prefixes if that fails for some reason.  But we expect
// MSXML2.XMLHTTP or Microsoft.XMLHTTP to actually work.
//
// MSXML2 prefix specifies the version independent control.  The "Microsoft" and "MSXML"
// prefixes are old-style version independent controls.  MSXML3 is version specific 3.0 parser.
//                     IE6+               IE5.5               pre-IE5.5 style  IE6+
xmlHttpConstructors : ["MSXML2.XMLHTTP", "Microsoft.XMLHTTP", "MSXML.XMLHTTP", "MSXML3.XMLHTTP"],

// ==========================================================================================
// IMPORTANT: If you update this function, also update its copy in FileLoader.js
// ==========================================================================================
createXMLHttpRequest : function () {
    
    if (isc.Browser.isIE) {

        var xmlHttpRequest;

        // We prefer the  ActiveX version of XMLHttpRequest if it's available because IE7's
        // native implementation has some quirks - for example it doesn't allow requests to
        // file:// URLs no matter what overrides you set in IE's options panel.  Also there
        // are scattered reports of the native implementation being less performant.
        if (this.preferNativeXMLHttpRequest) {
            xmlHttpRequest = this.getNativeRequest();
            if (!xmlHttpRequest) xmlHttpRequest = this.getActiveXRequest();
        } else {
            xmlHttpRequest = this.getActiveXRequest();        
            if (!xmlHttpRequest) xmlHttpRequest = this.getNativeRequest();
        }
   
        if (!xmlHttpRequest) isc.rpc.logWarn("Couldn't create XMLHttpRequest");
        return xmlHttpRequest;
    } else {
        // Moz, Safari
        return new XMLHttpRequest();
    }
},

getNativeRequest : function () {
   var xmlHttpRequest;
    if (isc.Browser.version >= 7) {
        isc.rpc.logDebug("Using native XMLHttpRequest");
        xmlHttpRequest = new XMLHttpRequest();
    }
    return xmlHttpRequest;
},

getActiveXRequest : function () {
    var xmlHttpRequest;

    if (!this._xmlHttpConstructor) {
        for (var i = 0; i < this.xmlHttpConstructors.length; i++) {
            try {
                var cons = this.xmlHttpConstructors[i];
                xmlHttpRequest = new ActiveXObject(cons);
                // cache selected constructor
                if (xmlHttpRequest) {
                    this._xmlHttpConstructor = cons;
                    break;
                }
            } catch (e) { }
        }
    } else {
        xmlHttpRequest = new ActiveXObject(this._xmlHttpConstructor);    
    }

    if (xmlHttpRequest) isc.rpc.logDebug("Using ActiveX XMLHttpRequest via constructor: " + this._xmlHttpConstructor);
    return xmlHttpRequest;
},


// Comm.sendHiddenFrame() defined in `application/SCServer.js'.


// _transactionCallbacks - array of callbacks for outstanding transactions
// fired from the various 'reply' methods
_transactionCallbacks:[],

// scriptInclude transport
// ---------------------------------------------------------------------------------------

sendScriptInclude : function (request) {
    var URL = request.URL,
        fields = request.fields,
        data = request.data,
        callbackParam = request.callbackParam,
        transaction = request.transaction
    ;
    
    // create a function for server-generated code to call, and capture the
    // transactionNum by having the function share this scope
    var cbName = "_scriptIncludeReply_"+transaction.transactionNum;
    this[cbName] = function () {
        // copy arguments to a real array
        var values = arguments.length == 1 ? arguments[0] : [];
        if (arguments.length > 1) {
            for (var i = 0; i < arguments.length; i++) values[i] = arguments[i];
        }
        isc.Comm.performScriptIncludeReply(transaction.transactionNum, values);
    }
    var callback = "isc.Comm."+cbName;

    var callbackParamObj = {};
    callbackParamObj[callbackParam ? callbackParam : "callback"] = callback;
    URL = isc.rpc.addParamsToURL(URL, fields);
    URL = isc.rpc.addParamsToURL(URL, callbackParamObj);
    if (transaction) transaction.mergedActionURL = URL;

    isc.rpc.logInfo("scriptInclude call to: " + URL);
    
    // store the transactionCallback to fire when the server returns
    this._transactionCallbacks[transaction.transactionNum] = transaction.callback;

    
    var document = this.getDocument(),
        body = this.getDocumentBody(),
        scriptElement = document.createElement("script");
    scriptElement.src = URL;
    body.appendChild(scriptElement);
},


performScriptIncludeReply : function (transactionNum, values) {
    // destroy auto-generated function for this transaction
    delete this["_scriptIncludeReply_"+transactionNum];
    var callback = this._transactionCallbacks[transactionNum];
    delete this._transactionCallbacks[transactionNum];
    
    this.logDebug("scriptInclude reply for transactionNum: " + transactionNum +
                  ", data: " + this.echoLeaf(values), "xmlBinding");

    this.fireCallback(callback, "transactionNum,results,wd", [transactionNum, values]);
},


// send via an xmlHttpRequest
sendXmlHttpRequest : function (request) {

    var URL = request.URL,
        fields = request.fields,
        httpMethod = request.httpMethod,
        contentType = request.contentType,
        headers = request.httpHeaders,
        data = request.data,
        transaction = request.transaction,
        blocking = request.blocking != null ? request.blocking : false
    ;


    
    
    this._transactionCallbacks[transaction.transactionNum] = transaction.callback;
    
    
    // set up a callback to notify us when the request completes
    var callback = "isc.Comm.performXmlTransactionReply(" +transaction.transactionNum+
                    ", xmlHttpRequest)";
                    
    if (!httpMethod) httpMethod = "POST";
    var xmlHttpRequest = this.createXMLHttpRequest();

    var loadFunc;
    if (isc.Browser.isIE) {
        
        loadFunc = this._getStateChangeHandler();
        loadFunc.request = xmlHttpRequest;
        loadFunc.callback = callback;

    } else {
        // we'll install this function to fire onreadystatechange
        loadFunc = function () {
        
        if (xmlHttpRequest.readyState != 4) return;
        isc.Comm._fireXMLCallback(xmlHttpRequest, callback);
        }   
    }
    xmlHttpRequest.onreadystatechange = request.onreadystatechange || loadFunc;

    if (isc.rpc.logIsDebugEnabled()) {
        this.lastXmlHttpRequest = xmlHttpRequest; // HACK for debugging
    }

    if (httpMethod == "POST" || httpMethod == "PUT") {
        // if data was passed in, use that as the body and encode any fields into the query
        // params
        if (data) {
            // assume the body being posted is XML if contentType is unset
            contentType = contentType || "text/xml";             
            URL = isc.rpc.addParamsToURL(URL, fields);
        } else {
            // send fields like a form post
            contentType = contentType || "application/x-www-form-urlencoded; charset=UTF-8";
            data = isc.SB.create();
            var first = true;
            for (var fieldName in fields) {
                if (!first) data.append("&");
                var value = fields[fieldName];
                data.append(isc.rpc.encodeParameter(fieldName, value));
                first = false;
            }
            data = data.toString();                        
        }
        if (isc.rpc.logIsDebugEnabled()) {
            isc.rpc.logDebug("XMLHttpRequest POST to " + URL + " contentType: " + contentType 
                             + " with body -->"+decodeURIComponent(data)+"<--");
        }
        xmlHttpRequest.open(httpMethod, URL, !blocking);
        
        var contentTypeSet = this._setHttpHeaders(xmlHttpRequest, headers);
        if (!contentTypeSet) {
            contentType == xmlHttpRequest.setRequestHeader("Content-Type", contentType);
        }
        if (transaction) {
            transaction.xhrHeaders = headers;
            transaction.xhrData = data;
        }
        if (data != null && !isc.isA.String(data)) {
            this.logWarn("Non-string data object passed to sendXML as request.data:"+ this.echo(data) +
                        " attempting to convert to a string.");
            data = data.toString ? data.toString() : "" + data;
        }
        xmlHttpRequest.send(data);
    } else {  // httpMethod == GET, DELETE, HEAD
        var urlWithFields = isc.rpc.addParamsToURL(URL, fields);
        xmlHttpRequest.open(httpMethod, urlWithFields, !blocking);

        // If bypassCache is set, use if-modified-since header to prevent cacheing of
        // XMLHttp GET responses.
        if (request.bypassCache) {
              
            xmlHttpRequest.setRequestHeader("If-Modified-Since", "Thu, 01 Jan 1970 00:00:00 GMT");
        }

        this._setHttpHeaders(xmlHttpRequest, headers);

        if (isc.rpc.logIsDebugEnabled()) {
            isc.rpc.logDebug("XMLHttpRequest GET from " + URL + 
                             " with fields: " + isc.Log.echoAll(fields) + 
                             " full URL string: " + urlWithFields);
        }
        
        xmlHttpRequest.send(null);
    }
    return xmlHttpRequest;
},




performXmlTransactionReply : function (transactionNum, xmlHttpRequest) {
    //!OBFUSCATEOK
    var callback = this._transactionCallbacks[transactionNum]
    delete this._transactionCallbacks[transactionNum];
    this.fireCallback(callback, "transactionNum,results,wd", [transactionNum, xmlHttpRequest]);
},

_setHttpHeaders : function (request, headers) {
    if (headers == null) return;
    var sawContentType = false;
    for (var headerName in headers) {
        var headerValue = headers[headerName];
        if (headerValue != null) {
            request.setRequestHeader(headerName, headerValue);
            if (headerName.toLowerCase() == "content-type") sawContentType = true;
        }
    }
    return sawContentType;
}

});

