/* rpc-combined: sets up object for XMLHttprequest method of rpc
 * or iframe method
 *
 * functions
 *    addEvent (optional): to assign handler to window.onload event
 *    createHTTPObj: controls creating an XMLHttprequest object or hidden iframe
 *    createXMLHttp: creates the XMLHttprequest object
 *    createExtIframe: calls routine to create the hidden iframe and extends the iframe
 *    createIframe: creates the hidden iframe
 *    callb: method used by iframe page to callback when loaded
 *    openMethod: compatibility method, writes url to iframe
 *    sendMethod: compatibility method, writes url to custom property of iframe
 *
 *    do_rpc: the event handler for user activity that starts rpc
 *    formatURL: formats url adding search string and a flag
 *    form2query: creates search string from a form
 */
var HTTPObj = null;
var HTTPtarget = null; //because IE's activeX can't be extended

if (!HTTPObj)
	addEvent(window, "load", createHTTPObj);

/* The demonstration uses an add/remove event library available at
 * http://lawrence.ecorp.net/inet/samples/js-addevent1.shtml
 * or you can uncomment and use the following function
 */
function addEvent(obj, event_name, fnc, assigment_only) {
    var rtrn = true;
    if (typeof obj == "undefined") {return false;}


    if (obj.attachEvent) {
        obj.attachEvent("on"+event_name, fnc);
    }
    else if (obj.addEventListener) {
        try {
            obj.addEventListener(event_name, fnc, false);
        } catch (e) {
            obj["on"+event_name]=fnc;
        }
    }
    else {
        obj["on"+event_name]=fnc;
    }
    return rtrn;
}//eof addEvent


function createHTTPObj() {
    
    if (!HTTPObj
        && !(window.console 
             && window.console.firebug)) {
        createXMLHttp();
    }
    
    if (!HTTPObj) {
        createExtIframe();
    }
}

function createXMLHttp() {
    /* Creates an XMLHttp object */
    var httpReq = HTTPObj;
    if (!httpReq) {
        if (typeof window.XMLHttpRequest !='undefined' ) {
            // branch for native XMLHttpRequest object - Mozilla
            try {
                httpReq = new XMLHttpRequest();
            }
            catch (e) {
                httpReq = null;
            }
        }
        else if (typeof window.ActiveXObject !='undefined') {
            // branch for IE/Windows ActiveX version
            try {
                httpReq = new ActiveXObject("Msxml2.XMLHTTP");
            }
            catch(e) {
                try{
                    httpReq = new ActiveXObject("Microsoft.XMLHTTP");
                }
                catch(e) {
                    httpReq = null;
                }
            }//catch
        } else if (typeof window.createRequest) {
            /* For ICEbrowser -- untested.
             * per their site http://support.icesoft.com/jive/entry.jspa?entryID=471&categoryID=21
             * There are a number of restrictions on the implementation and it only does get
             */
            try {
                httpReq = window.createRequest();
            }
            catch (e) {
                httpReq = null;
            }
        }//end if-else
    }//end if

    if (httpReq && typeof httpReq.readyState == "number") {
        try {
            httpReq.backbutton = false;
            httpReq.RPCType = "ajaxg";
            httpReq.targetId = "";
            httpReq.nexturl = "";
        } catch (e) {
            /* We can't extend active X objects */
        }
    } else {
        httpReq  = null;
    }
    HTTPObj = httpReq;
}//eof createHTTPObj

function createExtIframe() {

    /* Test if Iframe needs to be created */
    var iframeObj = document.getElementById("rs-iframe");
    if (!iframeObj) {
        iframeObj = createIframe();
    }

    /* Extend the iframe*/
    if (iframeObj) {
        iframeObj.backbutton = false;
        iframeObj.RPCType = "iframe2";
        iframeObj.targetId = "";
        iframeObj.onreadystatechange = "";
        try {
            iframeObj.readyState = 0;
        } catch (e) {
            /* IE already has this property as a
             * read only text with the values of
             * uninitialized, loading, loaded, interactive, and complete
             * so we just catch the error and go on.
             */
        }

        iframeObj.status = 0;
        iframeObj.nexturl = "";
        iframeObj.responseText = "";
        iframeObj.callBack = callb;
        iframeObj.open = openMethod;
        iframeObj.send = sendMethod;
        //iframeObj.window = getWindowHandle(iframeObj);
    }

    HTTPObj = iframeObj;

}//eof createHTTPObj

function getWindowHandle(iframeObj) {
    var iframeWin = null;

    /* Get handle to iframe window */
    if (iframeObj.contentWindow) { // IE5.5+, Mozilla, NN7
        iframeWin = iframeObj.contentWindow;
    }
    else if (iframeObj.contentDocument) { // NN6, Konqueror
        iframeWin = iframeObj.contentDocument.defaultView;
    }
    else if (iframeObj.Document) { // IE5
        iframeWin = iframeObj.Document.parentWindow;
    }

    return iframeWin;
}

function createIframe(i_FrameName) {
	
	if (!i_FrameName)
		i_FrameName = 'rs-iframe';
	
    /* Routine to create hidden iframe
     * Discovered that wrapping the iframe in
     * a div with display none works well in
     * most, if not all, common browsers.
     *
     * Note this test iframeObj.nodeType == "undefined"
     * is to trap some browsers that create a useless iframe.
     * For example Konqueror 3.2 and earlier.
     */
    var iframeObj = null;
    try {
        //Create Iframe and put it at bottom of page
        var tmpFrame;
        //IE 6.0 fix using wrapper div with display none
        var tmpDiv = document.createElement("div");
        tmpDiv.setAttribute("id", "iframe-div");
        tmpFrame = document.createElement("iframe");
        tmpFrame.setAttribute("id", i_FrameName);
        tmpFrame.setAttribute("name", i_FrameName);

        if (typeof document.body.getAttribute("className") == 'string')
            tmpFrame.setAttribute("className", "hidden-frame");
        else
            tmpFrame.setAttribute("class", "hidden-frame");

        tmpDiv.appendChild(tmpFrame);
        document.body.appendChild(tmpDiv);

        if (typeof document.frames != "undefined") {
            /* Required for IE 5 on Mac and throws error on IE 5.0 PC
             * which we need to branch to a different process.
             */
            iframeObj = document.frames[i_FrameName];
        }

        if (!iframeObj || typeof iframeObj.nodeType == "undefined") {
           /* Most browsers yield null or good iframe reference above,
            * but some return an object with no properties so nodeType test.
            */
            iframeObj = document.getElementById(i_FrameName);
        }
    }
    catch (e) {
       /* Hack to handle IE 5.0 on PC, which doesn't want to 'automate'
        * adding an iframe.
        *
        * Reguired:
        * 1. HTML string for iframe and NOT an element object.
        * 2. use iframe src attribute to load first RPC; otherwise only subsequent calls work
        * 3. A block container to hold iframe
        * 4. Attach container and iframe to any block inside body but NOT the body.
        */

        /* Put iframe in container (innerHTML must be used)
         * and append to any div in page (this may exist from above)
         */
        var iframeHTML='<iframe id="'+i_FrameName+'" name="'+i_FrameName+'" class="hidden-frame"><\/iframe>';
        if (!document.getElementById("iframe-div")) {
            tmpDiv = document.createElement("div");
            tmpDiv.setAttribute("id", "iframe-div");
            tmpDiv.innerHTML = iframeHTML;
            document.getElementsByTagName('DIV')[0].appendChild(tmpDiv);
        } else {
            document.getElementById("iframe-div").innerHTML = iframeHTML;
        }
        iframeObj = document.getElementById(i_FrameName);
    }
    /* How did we do? Return if alternate page should load */
    if (iframeObj && typeof iframeObj.nodeType == "undefined") {
        iframeObj = null;
    }
    return iframeObj;
}//eof createIframe

function callb(txt) {
    this.status = 200;
    this.responseText = txt;

    try {
        this.readyState = 4;
    } catch (e) {
       /* IE already has this property for iframes as a
        * read only text with the values of
        * uninitialized, loading, loaded, interactive, and complete
        * so we just catch the error and go on.
        */
    }
    this.onreadystatechange();
}//eof callb

function openMethod(method, url) {
    this.nexturl = url;
}//eof openMethod

function sendMethod() {
    /* IE 5.0 requires this for each RPC */
    this.window = getWindowHandle(this);

    if (this.window) {
        if (this.backButton) {
            this.src = this.nexturl;
        } else {
            this.window.location.replace(this.nexturl);
        }
    }
}//eof sendMethod

function do_rpc(url, target_elem, data, handler) {
    /* 1. test if the browser has the necessary
     *    features for the RPC and to handle the response data.
     * 2. Do any preprocessing for the URL
     *    e.g. assembling a query string from form fields
     * 3. Make call to server
     * 4. return if consolation/alternate page in form action
     *    or link's href should load
     */
    var doDefault = true;
    if (HTTPObj) {
        /* Assign reference to block receiving results.*/
        try {
            HTTPObj.targetId  = target_elem;
        } catch (e) {
            /* for IE active X */
            HTTPtarget = target_elem;
        }

		// update iframe state for IE6 / non-activeX
		if (HTTPObj.RPCType == 'iframe2')
		{
			if (HTTPObj.readyState == 4)
				HTTPObj.readyState == 0;
			else
				HTTPObj.readyState == "";
	
			HTTPObj.status = 0;
			HTTPObj.responseText = '';
		}
		
        var formatedURL = formatURL(url, data); //for IE's activeX
        HTTPObj.open("GET", formatedURL, true);
        HTTPObj.onreadystatechange = handler;
        HTTPObj.send(null);
        doDefault = false;
    } else {
        doDefault = true;
    }
    return doDefault;
}//eof do_rpc

function getRPCType() {
    var RPCType = null;
    if (HTTPObj.RPCType) {
        RPCType = HTTPObj.RPCType;
    } else {
        /* For IE Active X */
        RPCType = "ajaxg";
    }
    return RPCType;
}//eof getRPCType

function formatURL(url, data) {
    /* Assemble query string and append to url*/
    var type = "type=" + getRPCType();

    if (data) {
        switch (typeof data) {
        case "object":
            //Get string from form like method get
            if (data.tagName.toLowerCase() == "form") {
                url += form2query(data);
            }
            url += "&" + type;
            break;
        case "string":
            //formated string supplied
            if (!/^[?]/.test(data) ) {
                data = '?' + data;
            }
            url += data + "&" + type;
            break;
        default:
            url += "?" + type; //use what is passed with url
        }
    } else {
        if (url.indexOf("?") == -1)
            url += "?" + type;
        else
            url += "&" + type;
    }
    return url;
}//eof formatURL

function form2query(frm) {
    /* To string together fieldname
     * value pairs from form elements
     * with name property set.
     *
     * Format ?name=value&name=value ...
     */
    var qry = "";   //final query string
    var pair = "?"; //format one name/value pair
    var field;      //form field being processed

    for (var i = 0; i < frm.elements.length; i++) {

        field = frm.elements[i];

        if (typeof field.name != "undefined" && field.name != "") {

            switch (field.type) {
            case "select-one":
                pair += field.name + "=" + field.options[field.selectedIndex].value;
                break;
            case "radio":
            case "checkbox":
                if (field.checked) {
                    pair += field.name + "=" + field.value;
                }
                break;
            default:
                pair += field.name + "=" + field.value;
            }

            if (pair.length > 1) {
                /* Test in case first element
                 * is unchecked radio or checkbox
                 */
                qry += pair;
                pair = "&";
            }
        }
    }
    return qry;
}//eof form2query