var xmlBusinessCategory;

/**
 * XML_XPathExpression is a class that encapsulates an XPath query and its
 * associated namespace prefix-to-URL mapping. Once an XML_XPathExpression
 * object has been created, it can be evaluated one or more times (in one
 * or more contexts) using the getNode() or getNodes() methods.
 *
 * The first argument to this constructor is the text of the XPath expression.
 *
 * If the expression includes any XML namespaces, the second argument must
 * be a JavaScript object that maps namespace prefixes to the URLs that define
 * those namespaces. The properties of this object are the prefixes, and
 * the values of those properties are the URLs.
 */
function XML_XPathExpression (xpathText, namespaces) {
    this.xpathText = xpathText;    // Save the text of the expression
    this.namespaces = namespaces;  // And the namespace mapping
    if (document.createExpression) {
        // If we're in a W3C-compliant browser, use the W3C API
        // to compile the text of the XPath query
        this.xpathExpr =
            xmlBusinessCategory.createExpression(xpathText,
                                      // This function is passed a
                                      // namespace prefix and returns the URL.
                                      function(prefix) {
                                          return namespaces[prefix];
                                      });
    }
    else {
        // Otherwise, we assume for now that we're in IE and convert the
        // namespaces object into the textual form that IE requires.
        this.namespaceString = "";
        if (namespaces != null) {
            for(var prefix in namespaces) {
                // Add a space if there is already something there
                if (this.namespaceString) this.namespaceString += ' ';
                // And add the namespace
                this.namespaceString += 'xmlns:' + prefix + '="' +
                    namespaces[prefix] + '"';
            }
        }
    }
};
/**
 * This is the getNodes() method of XML_XPathExpression. It evaluates the
 * XPath expression in the specified context. The context argument should
 * be a Document or Element object. The return value is an array
 * or array-like object containing the nodes that match the expression.
 */
XML_XPathExpression.prototype.getNodes = function(context) {
    if (this.xpathExpr) {
        // If we are in a W3C-compliant browser, we compiled the
        // expression in the constructor. We now evaluate that compiled
        // expression in the specified context.
        var result =
            this.xpathExpr.evaluate(context,
                                    // This is the result type we want
                                    XPathResult.ORDERED_NODE_SNAPSHOT_TYPE,
                                    null);
        // Copy the results we get into an array.
        var a = new Array(result.snapshotLength);
        for(var i = 0; i < result.snapshotLength; i++) {
            a[i] = result.snapshotItem(i);
        }
        return a;
    }
    else {
        // If we are not in a W3C-compliant browser, attempt to evaluate
        // the expression using the IE API.
        try {
            // We need the Document object to specify namespaces
            var doc = context.ownerDocument;
            // If the context doesn't have ownerDocument, it is the Document
            if (doc == null) doc = context;
            // This is IE-specific magic to specify prefix-to-URL mapping
            doc.setProperty("SelectionLanguage", "XPath");
            doc.setProperty("SelectionNamespaces", this.namespaceString);
            // In IE, the context must be an Element not a Document,
            // so if context is a document, use documentElement instead
            if (context == doc) context = doc.documentElement;
            // Now use the IE method selectNodes() to evaluate the expression
            return context.selectNodes(this.xpathText);
        }
        catch(e) {
            // If the IE API doesn't work, we just give up
            throw "XPath not supported by this browser.";
        }
    }
}
/**
 * This is the getNode() method of XML_XPathExpression. It evaluates the
 * XPath expression in the specified context and returns a single matching
 * node (or null if no node matches). If more than one node matches,
 * this method returns the first one in the document.
 * The implementation differs from getNodes() only in the return type.
 */
XML_XPathExpression.prototype.getNode = function(context) {
    if (this.xpathExpr) {
        var result =
            this.xpathExpr.evaluate(context,
                                    // We just want the first match
                                    XPathResult.FIRST_ORDERED_NODE_TYPE,
                                    null);
        return result.singleNodeValue;
    }
    else {
        try {
            var doc = context.ownerDocument;
            if (doc == null) doc = context;
            doc.setProperty("SelectionLanguage", "XPath");
            doc.setProperty("SelectionNamespaces", this.namespaceString);
            if (context == doc) context = doc.documentElement;
            // In IE call selectSingleNode instead of selectNodes
            return context.selectSingleNode(this.xpathText);
        }
        catch(e) {
            throw "XPath not supported by this browser.";
        }
    }
};
/*
// A utility to create an XML_XPathExpression and call getNodes() on it
XML.getNodes = function(context, xpathExpr, namespaces) {
    return (new XML.XPathExpression(xpathExpr, namespaces)).getNodes(context);
};
// A utility to create an XML.XPathExpression and call getNode() on it
XML.getNode  = function(context, xpathExpr, namespaces) {
    return (new XML.XPathExpression(xpathExpr, namespaces)).getNode(context);
};
*/

/*-----------------------------------------------------------------------------------*/
/*  Above are the XPath class zhangweiwu copied from Javascript The Definitive Guide */
/*-----------------------------------------------------------------------------------*/
/* XML.getNode and XML.getNodes are fine, but they don't work on IE, hance the below */
function XML_getNodes(context, xpathExpr, namespaces) {
    return (new XML_XPathExpression(xpathExpr, namespaces)).getNodes(context);
};
function XML_getNode(context, xpathExpr, namespaces) {
    return (new XML_XPathExpression(xpathExpr, namespaces)).getNode(context);
};


if (window.addEventListener) /* DOM */
	window.addEventListener("load", load_xml_for_bcselection, false);
else /* IE */
	window.attachEvent("onload", load_xml_for_bcselection)

function load_xml_for_bcselection() {
	/* this part of code is added later for supporting index page */
	var branchCode;
	if (! document.getElementById("SubBranchSelection"))
		return;
	if (/[a-c][0-9]*/g.test(document.getElementById("SubBranchSelection").value))
	{
		branchCode = RegExp.lastMatch.substr(0,3);
		subbranchCode = (RegExp.lastMatch.length == 5 ) ? 
			RegExp.lastMatch.substr(3,2) : false;
	}
	if (document.implementation && document.implementation.createDocument) 
		xmlBusinessCategory = document.implementation.createDocument("", "", null);
	else
		xmlBusinessCategory = new ActiveXObject("MSXML2.DOMDocument");
	xmlBusinessCategory.async = false;
	xmlBusinessCategory.load("contactmgr/conf/BusinessCategory.xml");
	branchSelection = document.getElementById("BranchSelection");
	for (i = 1; i <= 3; i++)
	{
		xPath = "category[" + i + "]";
		topCategory = XML_getNode(xmlBusinessCategory.documentElement, xPath);
		if (topCategory.getAttribute("id") == branchCode) branchCode = xPath;
		topCategoryDescription = XML_getNode(xmlBusinessCategory.documentElement, xPath + "/description/text()");
		newOption = document.createElement("option");
		newOption.setAttribute("value", xPath);
		newOption.appendChild(document.createTextNode(topCategoryDescription.nodeValue));
		newOption.style.backgroundColor = "gray";
		branchSelection.appendChild(newOption);
		categoryGroups = XML_getNodes(topCategory, "category");
		for (j = 1; j <= categoryGroups.length; j++)
		{
			xxPath = xPath + "/category[" + j + "]";
			subCategory = XML_getNode(xmlBusinessCategory.documentElement, xxPath);
			if (subCategory.getAttribute("id") == branchCode) branchCode = xxPath;
			categoryGroupDescription = XML_getNode(xmlBusinessCategory.documentElement, xxPath + "/description/text()");
			newOption = document.createElement("option");
			newOption.setAttribute("value", xxPath);
			newOption.appendChild(document.createTextNode(categoryGroupDescription.nodeValue));
			newOption.style.backgroundColor = "silver";
			branchSelection.appendChild(newOption);
		}
	}
	if (branchCode) branchSelection.value = branchCode;
	branchSelection.onchange = function() { 
		document.getElementById("SubBranchSelection").disabled =
			(document.getElementById("BranchSelection").value == "Any");
		if (!document.getElementById("SubBranchSelection").disabled)
			updateSubBranchSelection(branchSelection = document.getElementById("BranchSelection").value);
	}
	branchSelection.onchange();
};

function updateSubBranchSelection(xPath) {
	subBranchSelection = document.getElementById("SubBranchSelection");
	oldValue = subBranchSelection.value;
	with (subBranchSelection) while (lastChild)	removeChild(firstChild);
	topId = XML_getNode(xmlBusinessCategory.documentElement, xPath).getAttribute("id");
	newOption = document.createElement("option");
	newOption.setAttribute("value", topId + "*");
	newOption.appendChild(document.createTextNode("All"));
	subBranchSelection.appendChild(newOption);
	subBranches = XML_getNodes(xmlBusinessCategory.documentElement, xPath + "//category");
	for (i = 0; i < subBranches.length; i++)
	{
			newOption = document.createElement("option");
			newOption.setAttribute("value", subBranches[i].getAttribute("id") + "*");
			dddescription = XML_getNode(subBranches[i], "description/text()");
			newOption.appendChild(document.createTextNode(dddescription.nodeValue));
			subBranchSelection.appendChild(newOption);
	}
	if (/[a-c][0-9]*\*/g.test(oldValue)) subBranchSelection.value = oldValue;
}