source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/core/TransformingReceptionist.java@ 26848

package org.greenstone.gsdl3.core;

import java.io.File;
import java.io.FileReader;
import java.io.Serializable;
import java.io.StringWriter;
import java.util.ArrayList;
import java.util.HashMap;

import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;
import org.apache.xerces.parsers.DOMParser;
import org.greenstone.gsdl3.action.Action;
import org.greenstone.gsdl3.util.GSConstants;
import org.greenstone.gsdl3.util.GSFile;
import org.greenstone.gsdl3.util.GSParams;
import org.greenstone.gsdl3.util.GSXML;
import org.greenstone.gsdl3.util.GSXSLT;
import org.greenstone.gsdl3.util.UserContext;
import org.greenstone.gsdl3.util.XMLConverter;
import org.greenstone.gsdl3.util.XMLTransformer;
import org.greenstone.util.GlobalProperties;
import org.w3c.dom.Comment;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.InputSource;

/**
 * A receptionist that uses xslt to transform the page_data before returning it.
 * . Receives requests consisting of an xml representation of cgi args, and
 * returns the page of data - in html by default. The requests are processed by
 * the appropriate action class
 * 
 * @see Action
 */
public class TransformingReceptionist extends Receptionist
{
    protected static final int CONFIG_PASS = 1;
    protected static final int TEXT_PASS = 2;

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.core.TransformingReceptionist.class.getName());

    /** The preprocess.xsl file is in a fixed location */
    static final String preprocess_xsl_filename = GlobalProperties.getGSDL3Home() + File.separatorChar + "interfaces" + File.separatorChar + "core" + File.separatorChar + "transform" + File.separatorChar + "preProcess.xsl";

    /** the list of xslt to use for actions */
    protected HashMap<String, String> xslt_map = null;

    /** a transformer class to transform xml using xslt */
    protected XMLTransformer transformer = null;

    protected TransformerFactory transformerFactory = null;
    protected DOMParser parser = null;

    protected HashMap<String, ArrayList<String>> _metadataRequiredMap = new HashMap<String, ArrayList<String>>();

    boolean _debug = true;

    public TransformingReceptionist()
    {
        super();
        this.xslt_map = new HashMap<String, String>();
        this.transformer = new XMLTransformer();
        try
        {
            transformerFactory = org.apache.xalan.processor.TransformerFactoryImpl.newInstance();
            this.converter = new XMLConverter();
            //transformerFactory.setURIResolver(new MyUriResolver()) ;

            parser = new DOMParser();
            parser.setFeature("http://xml.org/sax/features/validation", false);
            // don't try and load external DTD - no need if we are not validating, and may cause connection errors if a proxy is not set up.
            parser.setFeature("http://apache.org/xml/features/nonvalidating/load-external-dtd", false);
            // a performance test showed that having this on lead to increased 
            // memory use for small-medium docs, and not much gain for large 
            // docs.
            // http://www.sosnoski.com/opensrc/xmlbench/conclusions.html
            parser.setFeature("http://apache.org/xml/features/dom/defer-node-expansion", false);
            parser.setFeature("http://apache.org/xml/features/continue-after-fatal-error", true);
            // setting a handler for when fatal errors, errors or warnings happen during xml parsing
            // call XMLConverter's getParseErrorMessage() to get the errorstring that can be rendered as web page
            this.parser.setErrorHandler(new XMLConverter.ParseErrorHandler());
        }
        catch (Exception e)
        {
            e.printStackTrace();
        }
    }

    /** configures the receptionist - overwrite this to set up the xslt map */
    public boolean configure()
    {
        if (this.config_params == null)
        {
            logger.error(" config variables must be set before calling configure");
            return false;
        }
        if (this.mr == null)
        {
            logger.error(" message router must be set  before calling configure");
            return false;
        }

        // find the config file containing a list of actions
        File interface_config_file = new File(GSFile.interfaceConfigFile(GSFile.interfaceHome(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.INTERFACE_NAME))));
        if (!interface_config_file.exists())
        {
            logger.error(" interface config file: " + interface_config_file.getPath() + " not found!");
            return false;
        }
        Document config_doc = this.converter.getDOM(interface_config_file, "utf-8");
        if (config_doc == null)
        {
            logger.error(" could not parse interface config file: " + interface_config_file.getPath());
            return false;
        }
        Element config_elem = config_doc.getDocumentElement();
        String base_interface = config_elem.getAttribute("baseInterface");
        setUpBaseInterface(base_interface);
        setUpInterfaceOptions(config_elem);

        Element action_list = (Element) GSXML.getChildByTagName(config_elem, GSXML.ACTION_ELEM + GSXML.LIST_MODIFIER);
        NodeList actions = action_list.getElementsByTagName(GSXML.ACTION_ELEM);

        for (int i = 0; i < actions.getLength(); i++)
        {
            Element action = (Element) actions.item(i);
            String class_name = action.getAttribute("class");
            String action_name = action.getAttribute("name");
            Action ac = null;
            try
            {
                ac = (Action) Class.forName("org.greenstone.gsdl3.action." + class_name).newInstance();
            }
            catch (Exception e)
            {
                logger.error(" couldn't load in action " + class_name);
                e.printStackTrace();
                continue;
            }
            ac.setConfigParams(this.config_params);
            ac.setMessageRouter(this.mr);
            ac.configure();
            ac.addActionParameters(this.params);
            this.action_map.put(action_name, ac);

            // now do the xslt map
            String xslt = action.getAttribute("xslt");
            if (!xslt.equals(""))
            {
                this.xslt_map.put(action_name, xslt);
            }
            NodeList subactions = action.getElementsByTagName(GSXML.SUBACTION_ELEM);
            for (int j = 0; j < subactions.getLength(); j++)
            {
                Element subaction = (Element) subactions.item(j);
                String subname = subaction.getAttribute(GSXML.NAME_ATT);
                String subxslt = subaction.getAttribute("xslt");

                String map_key = action_name + ":" + subname;
                logger.debug("adding in to xslt map, " + map_key + "->" + subxslt);
                this.xslt_map.put(map_key, subxslt);
            }
        }
        Element lang_list = (Element) GSXML.getChildByTagName(config_elem, "languageList");
        if (lang_list == null)
        {
            logger.error(" didn't find a language list in the config file!!");
        }
        else
        {
            this.language_list = (Element) this.doc.importNode(lang_list, true);
        }

        getRequiredMetadataNamesFromXSLFiles();

        return true;
    }

    protected void getRequiredMetadataNamesFromXSLFiles()
    {
        ArrayList<File> xslFiles = GSFile.getAllXSLFiles((String) this.config_params.get(GSConstants.INTERFACE_NAME), (String) this.config_params.get(GSConstants.SITE_NAME));

        HashMap<String, ArrayList<String>> includes = new HashMap<String, ArrayList<String>>();
        HashMap<String, ArrayList<File>> files = new HashMap<String, ArrayList<File>>();
        HashMap<String, ArrayList<String>> metaNames = new HashMap<String, ArrayList<String>>();

        //First exploratory pass
        for (File currentFile : xslFiles)
        {
            Document currentDoc = this.converter.getDOM(currentFile);
            if (currentDoc == null) {
                // Can happen if an editor creates an auto-save temporary file 
                // (such as #header.xsl#) that is not well formed XML
                continue;
            }

            NodeList metadataElems = currentDoc.getElementsByTagNameNS(GSXML.GSF_NAMESPACE, "metadata"); //gsf:metadata
            NodeList foreachMetadataElems = currentDoc.getElementsByTagNameNS(GSXML.GSF_NAMESPACE, "foreach-metadata"); //gsf:foreach-metadata
            NodeList imageElems = currentDoc.getElementsByTagNameNS(GSXML.GSF_NAMESPACE, "image"); //gsf:image
            NodeList includeElems = currentDoc.getElementsByTagNameNS(GSXML.XSL_NAMESPACE, "include");
            NodeList importElems = currentDoc.getElementsByTagNameNS(GSXML.XSL_NAMESPACE, "import");

            ArrayList<String> names = new ArrayList<String>();
            for (int i = 0; i < metadataElems.getLength(); i++)
            {
                Element current = (Element) metadataElems.item(i);
                String name = current.getAttribute(GSXML.NAME_ATT);
                if (name != null && name.length() > 0 && !names.contains(name))
                {
                    names.add(name);
                }
            }

            for (int i = 0; i < foreachMetadataElems.getLength(); i++)
            {
                Element current = (Element) foreachMetadataElems.item(i);
                String name = current.getAttribute(GSXML.NAME_ATT);
                if (name != null && name.length() > 0 && !names.contains(name))
                {
                    names.add(name);
                }
            }

            for (int i = 0; i < imageElems.getLength(); i++)
            {
                Element current = (Element) imageElems.item(i);
                String type = current.getAttribute(GSXML.TYPE_ATT);
                if (type == null || type.length() == 0)
                {
                    continue;
                }

                if (type.equals("source"))
                {
                    String[] standardSourceMeta = new String[] { "SourceFile", "ImageHeight", "ImageWidth", "ImageType", "srcicon" };
                    for (String meta : standardSourceMeta)
                    {
                        if (!names.contains(meta))
                        {
                            names.add(meta);
                        }
                    }
                }
                else if (type.equals("screen"))
                {
                    String[] standardScreenMeta = new String[] { "Screen", "ScreenHeight", "ScreenWidth", "ScreenType", "screenicon" };
                    for (String meta : standardScreenMeta)
                    {
                        if (!names.contains(meta))
                        {
                            names.add(meta);
                        }
                    }
                }
                else if (type.equals("thumb"))
                {
                    String[] standardThumbMeta = new String[] { "Thumb", "ThumbHeight", "ThumbWidth", "ThumbType", "thumbicon" };
                    for (String meta : standardThumbMeta)
                    {
                        if (!names.contains(meta))
                        {
                            names.add(meta);
                        }
                    }
                }
            }

            metaNames.put(currentFile.getAbsolutePath(), names);

            ArrayList<String> includeAndImportList = new ArrayList<String>();
            for (int i = 0; i < includeElems.getLength(); i++)
            {
                includeAndImportList.add(((Element) includeElems.item(i)).getAttribute(GSXML.HREF_ATT));
            }
            for (int i = 0; i < importElems.getLength(); i++)
            {
                includeAndImportList.add(((Element) importElems.item(i)).getAttribute(GSXML.HREF_ATT));
            }
            includes.put(currentFile.getAbsolutePath(), includeAndImportList);

            String filename = currentFile.getName();
            if (files.get(filename) == null)
            {
                ArrayList<File> fileList = new ArrayList<File>();
                fileList.add(currentFile);
                files.put(currentFile.getName(), fileList);
            }
            else
            {
                ArrayList<File> fileList = files.get(filename);
                fileList.add(currentFile);
            }
        }

        //Second pass
        for (File currentFile : xslFiles)
        {
            ArrayList<File> filesToGet = new ArrayList<File>();
            filesToGet.add(currentFile);

            ArrayList<String> fullNameList = new ArrayList<String>();

            while (filesToGet.size() > 0)
            {
                File currentFileTemp = filesToGet.remove(0);

                //Add the names from this file
                ArrayList<String> currentNames = metaNames.get(currentFileTemp.getAbsolutePath());
                fullNameList.addAll(currentNames);

                ArrayList<String> includedHrefs = includes.get(currentFileTemp.getAbsolutePath());

                for (String href : includedHrefs)
                {
                    int lastSepIndex = href.lastIndexOf("/");
                    if (lastSepIndex != -1)
                    {
                        href = href.substring(lastSepIndex + 1);
                    }

                    ArrayList<File> filesToAdd = files.get(href);
                    if (filesToAdd != null)
                    {
                        filesToGet.addAll(filesToAdd);
                    }
                }
            }

            _metadataRequiredMap.put(currentFile.getAbsolutePath(), fullNameList);
        }
    }

    protected void preProcessRequest(Element request)
    {
        String action = request.getAttribute(GSXML.ACTION_ATT);
        String subaction = request.getAttribute(GSXML.SUBACTION_ATT);

        String name = null;
        if (!subaction.equals(""))
        {
            String key = action + ":" + subaction;
            name = this.xslt_map.get(key);
        }
        // try the action by itself
        if (name == null)
        {
            name = this.xslt_map.get(action);
        }

        String stylesheetFile = GSFile.interfaceStylesheetFile(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.INTERFACE_NAME), name);
        stylesheetFile = stylesheetFile.replace("/", File.separator);

        ArrayList<String> requiredMetadata = _metadataRequiredMap.get(stylesheetFile);

        if (requiredMetadata != null)
        {
            Element extraMetadataList = this.doc.createElement(GSXML.EXTRA_METADATA + GSXML.LIST_MODIFIER);

            for (String metadataString : requiredMetadata)
            {
                Element metadataElem = this.doc.createElement(GSXML.EXTRA_METADATA);
                metadataElem.setAttribute(GSXML.NAME_ATT, metadataString);
                extraMetadataList.appendChild(metadataElem);
            }
            request.appendChild(request.getOwnerDocument().importNode(extraMetadataList, true));
        }
    }

    protected Node postProcessPage(Element page)
    {
        // might need to add some data to the page
        addExtraInfo(page);
        // transform the page using xslt
        Node transformed_page = transformPage(page);

        // if the user has specified they want only a part of the full page then subdivide it
        boolean subdivide = false;
        String excerptID = null;
        String excerptTag = null;
        Element request = (Element) GSXML.getChildByTagName(page, GSXML.PAGE_REQUEST_ELEM);
        Element cgi_param_list = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        if (cgi_param_list != null)
        {
            HashMap<String, Serializable> params = GSXML.extractParams(cgi_param_list, false);
            if ((excerptID = (String) params.get(GSParams.EXCERPT_ID)) != null)
            {
                subdivide = true;
            }
            if ((excerptTag = (String) params.get(GSParams.EXCERPT_TAG)) != null)
            {
                subdivide = true;
            }
        }

        if (subdivide)
        {
            Node subdivided_page = subdivide(transformed_page, excerptID, excerptTag);
            if (subdivided_page != null)
            {
                return subdivided_page;
            }
        }

        return transformed_page;
    }

    protected Node subdivide(Node transformed_page, String excerptID, String excerptTag)
    {
        if (excerptID != null)
        {
            Node selectedElement = getNodeByIdRecursive(transformed_page, excerptID);
            modifyNodesByTagRecursive(selectedElement, "a");
            return selectedElement;
        }
        else if (excerptTag != null)
        {
            Node selectedElement = getNodeByTagRecursive(transformed_page, excerptTag);
            return selectedElement;
        }
        return transformed_page;
    }

    protected Node getNodeByIdRecursive(Node parent, String id)
    {
        if (parent.hasAttributes() && ((Element) parent).getAttribute("id").equals(id))
        {
            return parent;
        }

        NodeList children = parent.getChildNodes();
        for (int i = 0; i < children.getLength(); i++)
        {
            Node result = null;
            if ((result = getNodeByIdRecursive(children.item(i), id)) != null)
            {
                return result;
            }
        }
        return null;
    }

    protected Node getNodeByTagRecursive(Node parent, String tag)
    {
        if (parent.getNodeType() == Node.ELEMENT_NODE && ((Element) parent).getTagName().equals(tag))
        {
            return parent;
        }

        NodeList children = parent.getChildNodes();
        for (int i = 0; i < children.getLength(); i++)
        {
            Node result = null;
            if ((result = getNodeByTagRecursive(children.item(i), tag)) != null)
            {
                return result;
            }
        }
        return null;
    }

    protected Node modifyNodesByTagRecursive(Node parent, String tag)
    {
        if (parent == null || (parent.getNodeType() == Node.ELEMENT_NODE && ((Element) parent).getTagName().equals(tag)))
        {
            return parent;
        }

        NodeList children = parent.getChildNodes();
        for (int i = 0; i < children.getLength(); i++)
        {
            Node result = null;
            if ((result = modifyNodesByTagRecursive(children.item(i), tag)) != null)
            {
                //TODO: DO SOMETHING HERE?
            }
        }
        return null;
    }

    /**
     * overwrite this to add any extra info that might be needed in the page
     * before transformation
     */
    protected void addExtraInfo(Element page)
    {
    }

    /**
     * transform the page using xslt we need to get any format element out of
     * the page and add it to the xslt before transforming
     */
    protected Node transformPage(Element page)
    {
        _debug = false;

        boolean allowsClientXSLT = (Boolean) config_params.get(GSConstants.ALLOW_CLIENT_SIDE_XSLT);
        //System.out.println("Client side transforms allowed? " + allowsClientXSLT);

        String currentInterface = (String) config_params.get(GSConstants.INTERFACE_NAME);

        Element request = (Element) GSXML.getChildByTagName(page, GSXML.PAGE_REQUEST_ELEM);
        String output = request.getAttribute(GSXML.OUTPUT_ATT);

        //System.out.println("Current output mode is: " + output + ", current interface name is: " + currentInterface);

        if (allowsClientXSLT)
        {
            if (!currentInterface.endsWith(GSConstants.CLIENT_SIDE_XSLT_INTERFACE_SUFFIX) && output.equals("html"))
            {
                System.out.println("output is html and we are not currently using a client side version, switching");
                // Switch the interface
                config_params.put(GSConstants.INTERFACE_NAME, currentInterface.concat(GSConstants.CLIENT_SIDE_XSLT_INTERFACE_SUFFIX));
            }
            else if ((currentInterface.endsWith(GSConstants.CLIENT_SIDE_XSLT_INTERFACE_SUFFIX) && !output.equals("html")) || output.equals("server"))
            {
                // The reverse needs to happen too
                config_params.put(GSConstants.INTERFACE_NAME, currentInterface.substring(0, currentInterface.length() - GSConstants.CLIENT_SIDE_XSLT_INTERFACE_SUFFIX.length()));
            }
        }
        else if (currentInterface.endsWith(GSConstants.CLIENT_SIDE_XSLT_INTERFACE_SUFFIX))
        {
            config_params.put(GSConstants.INTERFACE_NAME, currentInterface.substring(0, currentInterface.length() - GSConstants.CLIENT_SIDE_XSLT_INTERFACE_SUFFIX.length()));
        }

        // DocType defaults in case the skin doesn't have an "xsl:output" element
        String qualifiedName = "html";
        String publicID = "-//W3C//DTD HTML 4.01 Transitional//EN";
        String systemID = "http://www.w3.org/TR/html4/loose.dtd";

        // We need to create an empty document with a predefined DocType,
        // that will then be used for the transformation by the DOMResult
        Document docWithDoctype = converter.newDOM(qualifiedName, publicID, systemID);

        if (output.equals("xsltclient"))
        {
            // If you're just getting the client-side transform page, why bother with the rest of this?
            Element html = docWithDoctype.createElement("html");
            Element img = docWithDoctype.createElement("img");
            img.setAttribute("src", "interfaces/default/images/loading.gif"); // Make it dynamic
            img.setAttribute("alt", "Please wait...");
            Text title_text = docWithDoctype.createTextNode("Please wait..."); // Make this language dependent
            Element head = docWithDoctype.createElement("head");
            Element title = docWithDoctype.createElement("title");
            title.appendChild(title_text);
            Element body = docWithDoctype.createElement("body");
            Element script = docWithDoctype.createElement("script");
            Element jquery = docWithDoctype.createElement("script");
            jquery.setAttribute("src", "jquery.js");
            jquery.setAttribute("type", "text/javascript");
            Comment jquery_comment = docWithDoctype.createComment("jQuery");
            Comment script_comment = docWithDoctype.createComment("Filler for browser");
            script.setAttribute("src", "test.js");
            script.setAttribute("type", "text/javascript");
            Element pagevar = docWithDoctype.createElement("script");
            Element style = docWithDoctype.createElement("style");
            style.setAttribute("type", "text/css");
            Text style_text = docWithDoctype.createTextNode("body { text-align: center; padding: 50px; font: 14pt Arial, sans-serif; font-weight: bold; }");
            pagevar.setAttribute("type", "text/javascript");
            Text page_var_text = docWithDoctype.createTextNode("var placeholder = true;");

            html.appendChild(head);
            head.appendChild(title);
            head.appendChild(style);
            style.appendChild(style_text);
            html.appendChild(body);
            head.appendChild(pagevar);
            head.appendChild(jquery);
            head.appendChild(script);
            pagevar.appendChild(page_var_text);
            jquery.appendChild(jquery_comment);
            script.appendChild(script_comment);
            body.appendChild(img);
            docWithDoctype.appendChild(html);

            return (Node) docWithDoctype;
        }

        // Passing in the pretty string here means it needs to be generated even when not debugging; so use custom function to return blank when debug is off
        logger.debug("page before transforming:");
        logger.debug(this.converter.getPrettyStringLogger(page, logger));

        String action = request.getAttribute(GSXML.ACTION_ATT);
        String subaction = request.getAttribute(GSXML.SUBACTION_ATT);

        // we should choose how to transform the data based on output, eg diff
        // choice for html, and wml??
        // for now, if output=xml, we don't transform the page, we just return 
        // the page xml
        Document theXML = null;

        if (output.equals("xml") || (output.equals("json")) || output.equals("clientside"))
        {
            // Append some bits and pieces first...
            theXML = converter.newDOM();
            // Import into new document first!
            Node newPage = theXML.importNode(page, true);
            theXML.appendChild(newPage);
            Element root = theXML.createElement("xsltparams");
            newPage.appendChild(root);

            Element libname = theXML.createElement("param");
            libname.setAttribute("name", "library_name");
            Text libnametext = theXML.createTextNode((String) config_params.get(GSConstants.LIBRARY_NAME));
            libname.appendChild(libnametext);

            Element intname = theXML.createElement("param");
            intname.setAttribute("name", "interface_name");
            Text intnametext = theXML.createTextNode((String) config_params.get(GSConstants.INTERFACE_NAME));
            intname.appendChild(intnametext);

            Element siteName = theXML.createElement("param");
            siteName.setAttribute("name", "site_name");
            Text siteNameText = theXML.createTextNode((String) config_params.get(GSConstants.SITE_NAME));
            siteName.appendChild(siteNameText);

            Element filepath = theXML.createElement("param");
            filepath.setAttribute("name", "filepath");
            Text filepathtext = theXML.createTextNode(GlobalProperties.getGSDL3Home());
            filepath.appendChild(filepathtext);

            root.appendChild(libname);
            root.appendChild(intname);
            root.appendChild(siteName);
            root.appendChild(filepath);

            if ((output.equals("xml")) || output.equals("json")) {
                // in the case of "json", calling method responsible for converting to JSON-string
                return theXML.getDocumentElement();
            }
        }


        Element cgi_param_list = (Element) GSXML.getChildByTagName(request, GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        String collection = "";
        String inlineTemplate = "";
        if (cgi_param_list != null)
        {
            // Don't waste time getting all the parameters
            HashMap<String, Serializable> params = GSXML.extractParams(cgi_param_list, false);
            collection = (String) params.get(GSParams.COLLECTION);
            if (collection == null)
            {
                collection = "";
            }

            inlineTemplate = (String) params.get(GSParams.INLINE_TEMPLATE);

            if (params.get(GSParams.DEBUG) != null && (((String) params.get(GSParams.DEBUG)).equals("on") || ((String) params.get(GSParams.DEBUG)).equals("1")))
            {
                _debug = true;
            }
        }

        config_params.put("collName", collection);

        Document style_doc = getXSLTDocument(action, subaction, collection);
        if (style_doc == null)
        {
            String errorPage = this.converter.getParseErrorMessage();
            if (errorPage != null)
            {
                return XMLTransformer.constructErrorXHTMLPage("Cannot parse the xslt file\n" + errorPage);
            }
            return page;
        }

        // put the page into a document - this is necessary for xslt to get
        // the paths right if you have paths relative to the document root
        // eg /page.
        Document doc = this.converter.newDOM();
        doc.appendChild(doc.importNode(page, true));
        Element page_response = (Element) GSXML.getChildByTagName(page, GSXML.PAGE_RESPONSE_ELEM);
        Element format_elem = (Element) GSXML.getChildByTagName(page_response, GSXML.FORMAT_ELEM);

        NodeList pageElems = doc.getElementsByTagName("page");
        if (pageElems.getLength() > 0)
        {
            Element pageElem = (Element) pageElems.item(0);
            String langAtt = pageElem.getAttribute(GSXML.LANG_ATT);

            if (langAtt != null && langAtt.length() > 0)
            {
                config_params.put("lang", langAtt);
            }
        }

        if (output.equals("formatelem"))
        {
            return format_elem;
        }
        if (format_elem != null)
        {
            //page_response.removeChild(format_elem);
            logger.debug("format elem=" + this.converter.getPrettyStringLogger(format_elem, logger));
            // need to transform the format info
            String configStylesheet_file = GSFile.stylesheetFile(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces, "config_format.xsl");
            Document configStylesheet_doc = this.converter.getDOM(new File(configStylesheet_file));

            if (configStylesheet_doc != null)
            {
                Document format_doc = this.converter.newDOM();
                format_doc.appendChild(format_doc.importNode(format_elem, true));

                if (_debug)
                {
                    String siteHome = GSFile.siteHome(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.SITE_NAME));
                    GSXSLT.insertDebugElements(format_doc, GSFile.collectionConfigFile(siteHome, collection));
                }

                Node result = this.transformer.transform(configStylesheet_doc, format_doc, config_params); // Needs addressing <-

                // Since we started creating documents with DocTypes, we can end up with 
                // Document objects here. But we will be working with an Element instead, 
                // so we grab the DocumentElement() of the Document object in such a case.
                Element new_format;
                if (result.getNodeType() == Node.DOCUMENT_NODE)
                {
                    new_format = ((Document) result).getDocumentElement();
                }
                else
                {
                    new_format = (Element) result;
                }
                logger.debug("new format elem=" + this.converter.getPrettyStringLogger(new_format, logger));
                if (output.equals("newformat"))
                {
                    return new_format;
                }

                // add extracted GSF statements in to the main stylesheet
                if (_debug)
                {
                    String siteHome = GSFile.siteHome(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.SITE_NAME));
                    GSXSLT.mergeStylesheetsDebug(style_doc, new_format, true, true, "OTHER1", GSFile.collectionConfigFile(siteHome, collection));
                }
                else
                {
                    GSXSLT.mergeStylesheets(style_doc, new_format, true);
                }
                //System.out.println("added extracted GSF statements into the main stylesheet") ;

                // add extracted GSF statements in to the debug test stylesheet
                //GSXSLT.mergeStylesheets(oldStyle_doc, new_format);
            }
            else
            {
                logger.error(" couldn't parse the config_format stylesheet, adding the format info as is");
                GSXSLT.mergeStylesheets(style_doc, format_elem, true);
                //GSXSLT.mergeStylesheets(oldStyle_doc, format_elem);
            }
            logger.debug("the converted stylesheet is:");
            logger.debug(this.converter.getPrettyStringLogger(style_doc.getDocumentElement(), logger));
        }

        //for debug purposes only
        Document oldStyle_doc = style_doc;
        Document preprocessingXsl;
        try
        {
            preprocessingXsl = getDoc(preprocess_xsl_filename);
            String errMsg = ((XMLConverter.ParseErrorHandler) parser.getErrorHandler()).getErrorMessage();
            if (errMsg != null)
            {
                return XMLTransformer.constructErrorXHTMLPage("error loading preprocess xslt file: " + preprocess_xsl_filename + "\n" + errMsg);
            }
        }
        catch (java.io.FileNotFoundException e)
        {
            return fileNotFoundErrorPage(e.getMessage());
        }
        catch (Exception e)
        {
            e.printStackTrace();
            System.out.println("error loading preprocess xslt");
            return XMLTransformer.constructErrorXHTMLPage("error loading preprocess xslt\n" + e.getMessage());
        }

        Document libraryXsl = null;
        try
        {
            String gsLibFile = this.getGSLibXSLFilename();
            if (new File(gsLibFile).exists())
            {
                libraryXsl = getDoc(gsLibFile);
                String errMsg = ((XMLConverter.ParseErrorHandler) parser.getErrorHandler()).getErrorMessage();
                if (errMsg != null)
                {
                    return XMLTransformer.constructErrorXHTMLPage("Error loading xslt file: " + this.getGSLibXSLFilename() + "\n" + errMsg);
                }
            }
        }
        catch (java.io.FileNotFoundException e)
        {
            return fileNotFoundErrorPage(e.getMessage());
        }
        catch (Exception e)
        {
            e.printStackTrace();
            System.out.println("error loading gslib xslt");
            return XMLTransformer.constructErrorXHTMLPage("error loading gslib xslt\n" + e.getMessage());
        }

        //   Combine the skin file and library variables/templates into one document. 
        //   Please note: We dont just use xsl:import because the preprocessing stage  
        //   needs to know what's available in the library.

        Document skinAndLibraryXsl = null;
        Document skinAndLibraryDoc = converter.newDOM();

        // Applying the preprocessing XSLT - in its own block {} to allow use of non-unique variable names
        {

            skinAndLibraryXsl = converter.newDOM();
            Element root = skinAndLibraryXsl.createElement("skinAndLibraryXsl");
            skinAndLibraryXsl.appendChild(root);

            Element s = skinAndLibraryXsl.createElement("skinXsl");
            s.appendChild(skinAndLibraryXsl.importNode(style_doc.getDocumentElement(), true));
            root.appendChild(s);

            Element l = skinAndLibraryXsl.createElement("libraryXsl");
            if (libraryXsl != null)
            {
                Element libraryXsl_el = libraryXsl.getDocumentElement();
                l.appendChild(skinAndLibraryXsl.importNode(libraryXsl_el, true));
            }
            root.appendChild(l);

            //System.out.println("Skin and Library XSL are now together") ;

            //System.out.println("Pre-processing the skin file...") ;

            //pre-process the skin style sheet
            //In other words, apply the preProcess.xsl to 'skinAndLibraryXsl' in order to
            //expand all GS-Lib statements into complete XSL statements and also to create
            //a valid xsl style sheet document.

            XMLTransformer preProcessor = new XMLTransformer();
            // Perform the transformation, by passing in:
            // preprocess-stylesheet, source-xsl (skinAndLibraryXsl), and the node that should 
            // be in the result (skinAndLibraryDoc)
            preProcessor.transform_withResultNode(preprocessingXsl, skinAndLibraryXsl, skinAndLibraryDoc);
            //System.out.println("GS-Lib statements are now expanded") ;
        }

        // there is a thing called a URIResolver which you can set for a
        // transformer or transformer factory. may be able to use this
        // instead of this absoluteIncludepaths hack

        //GSXSLT.absoluteIncludePaths(skinAndLibraryDoc, GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces);

        //Same but for the debug version when we want the do the transformation like we use to do
        //without any gslib elements.
        GSXSLT.absoluteIncludePaths(oldStyle_doc, GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces);

        //Send different stages of the skin xslt to the browser for debug purposes only
        //using &o=skindoc or &o=skinandlib etc...
        if (output.equals("skindoc"))
        {
            return converter.getDOM(getStringFromDocument(style_doc));
        }
        if (output.equals("skinandlib"))
        {
            return converter.getDOM(getStringFromDocument(skinAndLibraryXsl));
        }
        if (output.equals("skinandlibdoc") || output.equals("clientside"))
        {

            Node skinAndLib = converter.getDOM(getStringFromDocument(skinAndLibraryDoc));

            if (output.equals("skinandlibdoc"))
            {
                return skinAndLib;
            }
            else
            {
                // Send XML and skinandlibdoc down the line together
                Document finalDoc = converter.newDOM();
                Node finalDocSkin = finalDoc.importNode(skinAndLibraryDoc.getDocumentElement(), true);
                Node finalDocXML = finalDoc.importNode(theXML.getDocumentElement(), true);
                Element root = finalDoc.createElement("skinlibPlusXML");
                root.appendChild(finalDocSkin);
                root.appendChild(finalDocXML);
                finalDoc.appendChild(root);
                return (Node) finalDoc.getDocumentElement();
            }
        }
        if (output.equals("oldskindoc"))
        {
            return converter.getDOM(getStringFromDocument(oldStyle_doc));
        }

        // Try to get the system and public ID from the current skin xsl document
        // otherwise keep the default values.
        Element root = skinAndLibraryDoc.getDocumentElement();
        NodeList nodes = root.getElementsByTagName("xsl:output");
        // If there is at least one "xsl:output" command in the final xsl then...
        if (nodes.getLength() != 0)
        {
            // There should be only one element called xsl:output, 
            // but if this is not the case get the last one
            Element xsl_output = (Element) nodes.item(nodes.getLength() - 1);
            if (xsl_output != null)
            {
                // Qualified name will always be html even for xhtml pages
                //String attrValue = xsl_output.getAttribute("method");
                //qualifiedName = attrValue.equals("") ? qualifiedName : attrValue;

                String attrValue = xsl_output.getAttribute("doctype-system");
                systemID = attrValue.equals("") ? systemID : attrValue;

                attrValue = xsl_output.getAttribute("doctype-public");
                publicID = attrValue.equals("") ? publicID : attrValue;
            }
        }

        //System.out.println(converter.getPrettyString(docWithDoctype));
        //System.out.println("Doctype vals: " + qualifiedName + " " + publicID + " " + systemID) ;

        docWithDoctype = converter.newDOM(qualifiedName, publicID, systemID);

        //System.out.println("Generate final HTML from current skin") ;
        //Transformation of the XML message from the receptionist to HTML with doctype

        if (inlineTemplate != null)
        {
            try
            {
                Document inlineTemplateDoc = this.converter.getDOM("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<xsl:stylesheet version=\"1.0\" xmlns:xsl=\"" + GSXML.XSL_NAMESPACE + "\" xmlns:java=\"" + GSXML.JAVA_NAMESPACE + "\" xmlns:util=\"" + GSXML.UTIL_NAMESPACE + "\" xmlns:gsf=\"" + GSXML.GSF_NAMESPACE + "\">" + inlineTemplate + "</xsl:stylesheet>", "UTF-8");

                if (_debug)
                {
                    GSXSLT.mergeStylesheetsDebug(skinAndLibraryDoc, inlineTemplateDoc.getDocumentElement(), true, true, "OTHER2", "INLINE");
                }
                else
                {
                    GSXSLT.mergeStylesheets(skinAndLibraryDoc, inlineTemplateDoc.getDocumentElement(), true);
                }
            }
            catch (Exception ex)
            {
                ex.printStackTrace();
            }
        }

        if (_debug)
        {
            GSXSLT.inlineImportAndIncludeFilesDebug(skinAndLibraryDoc, null, _debug, this.getGSLibXSLFilename(), (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces);
        }
        else
        {
            GSXSLT.inlineImportAndIncludeFiles(skinAndLibraryDoc, null, (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces);
        }
        skinAndLibraryDoc = (Document) performFormatPass(collection, skinAndLibraryDoc, doc, new UserContext(request), TEXT_PASS);
        skinAndLibraryDoc = (Document) performFormatPass(collection, skinAndLibraryDoc, doc, new UserContext(request), CONFIG_PASS);

        if (output.equals("xmlfinal"))
        {
            return doc;
        }

        if (output.equals("skinandlibdocfinal"))
        {
            return converter.getDOM(getStringFromDocument(skinAndLibraryDoc));
        }

        Node finalResult = this.transformer.transform(skinAndLibraryDoc, doc, config_params, docWithDoctype);

        if (_debug)
        {
            GSXSLT.fixTables((Document) finalResult);
        }

        return finalResult;

        // The line below will do the transformation like we use to do before having Skin++ implemented,
        // it will not contain any GS-Lib statements expanded, and the result will not contain any doctype.

        //return (Element)this.transformer.transform(style_doc, doc, config_params);  
        //return null; // For now - change later
    }

    protected Node performFormatPass(String collection, Document skinAndLibraryDoc, Document doc, UserContext userContext, int pass)
    {
        String formatFile;
        if (pass == CONFIG_PASS)
        {
            formatFile = "config_format.xsl";
        }
        else
        {
            formatFile = "text_fragment_format.xsl";
        }
        String configStylesheet_file = GSFile.stylesheetFile(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces, formatFile);
        Document configStylesheet_doc = this.converter.getDOM(new File(configStylesheet_file));

        if (configStylesheet_doc != null)
        {
            return this.transformer.transform(configStylesheet_doc, skinAndLibraryDoc, config_params);
        }
        return skinAndLibraryDoc;
    }

    // method to convert Document to a proper XML string for debug purposes only
    protected String getStringFromDocument(Document doc)
    {
        String content = "";
        try
        {
            DOMSource domSource = new DOMSource(doc);
            StringWriter writer = new StringWriter();
            StreamResult result = new StreamResult(writer);
            TransformerFactory tf = TransformerFactory.newInstance();
            Transformer transformer = tf.newTransformer();
            transformer.transform(domSource, result);
            content = writer.toString();
            System.out.println("Change the & to &Amp; for proper debug display");
            content = StringUtils.replace(content, "&", "&amp;");
            writer.flush();
        }
        catch (TransformerException ex)
        {
            ex.printStackTrace();
            return null;
        }
        return content;
    }

    protected synchronized Document getDoc(String docName) throws Exception
    {
        File xslt_file = new File(docName);

        FileReader reader = new FileReader(xslt_file);
        InputSource xml_source = new InputSource(reader);
        this.parser.parse(xml_source);
        Document doc = this.parser.getDocument();

        return doc;
    }

    protected Document getXSLTDocument(String action, String subaction, String collection)
    {
        String name = null;
        if (!subaction.equals(""))
        {
            String key = action + ":" + subaction;
            name = this.xslt_map.get(key);
        }
        // try the action by itself
        if (name == null)
        {
            name = this.xslt_map.get(action);
        }
        if (name == null)
        {
            // so we can reandomly create any named page
            if (action.equals("p") && !subaction.equals(""))
            {
                // TODO: pages/ won't work for interface other than default!!
                name = "pages/" + subaction + ".xsl";
            }

        }
        Document finalDoc = GSXSLT.mergedXSLTDocumentCascade(name, (String) this.config_params.get(GSConstants.SITE_NAME), collection, (String) this.config_params.get(GSConstants.INTERFACE_NAME), base_interfaces, _debug);
        return finalDoc;
    }

    // returns the path to the gslib.xsl file that is applicable for the current interface
    protected String getGSLibXSLFilename()
    {
        return GSFile.xmlTransformDir(GSFile.interfaceHome(GlobalProperties.getGSDL3Home(), (String) this.config_params.get(GSConstants.INTERFACE_NAME))) + File.separatorChar + "gslib.xsl";
    }

    // Call this when a FileNotFoundException could be thrown when loading an xsl (xml) file.
    // Returns an error xhtml page indicating which xsl (or other xml) file is missing.
    protected Document fileNotFoundErrorPage(String filenameMessage)
    {
        String errorMessage = "ERROR missing file: " + filenameMessage;
        Element errPage = XMLTransformer.constructErrorXHTMLPage(errorMessage);
        logger.error(errorMessage);
        return errPage.getOwnerDocument();
    }
}