source: trunk/gsdl3/src/java/org/greenstone/gsdl3/action/AppletAction.java@ 3645

package org.greenstone.gsdl3.action;

import org.greenstone.gsdl3.core.ModuleInterface;
import org.greenstone.gsdl3.util.*;
// XML classes
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 
import org.w3c.dom.Document; 
import org.w3c.dom.Element; 

import java.util.HashMap;
import java.io.File;

/** action class for handling applets */
public class AppletAction extends Action {
    

    public Element process (Element message) {
    

    // find the stylesheet
    String stylesheet = GSFile.stylesheetFile(config_, "applet.xsl");

    if (stylesheet==null) {
        System.err.println("AppletAction Error: applet stylesheet not found!");
        return null;
    }
    
    Element request = (Element)GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
    
    // subaction is display (d) or request (r)
    String request_type = request.getAttribute(GSXML.SUBACTION_ATT); 
    if (!request_type.equals("d")&&!request_type.equals("r")) {
        System.err.println("AppletAction Error: the sa arg should be either d or r, instead it was "+request_type+"!");
        return null;
    }
    
    // get the collection and service param
    Element cgi_param_list = (Element)GSXML.getChildByTagName(request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    HashMap params = GSXML.extractParams(cgi_param_list);

    String collection = (String)params.get(GSCGI.COLLECTION_ARG);
    String service_name=(String)params.get(GSCGI.SERVICE_ARG);
    service_name+= "Applet";
    
    String to=null;
    if (collection==null||collection.equals("") ) {
        to = service_name;
    } else {
        to = GSPath.appendLink(collection, service_name);
    }

    if (request_type.equals("d")) {
        // we are just displaying the applet - get the description from
        // the service, and process using xslt

        //build up the mr request
    
        Element mr_message = doc_.createElement(GSXML.MESSAGE_ELEM);
        Element mr_request = doc_.createElement(GSXML.REQUEST_ELEM);
        mr_message.appendChild(mr_request);
        mr_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_DESCRIBE);
        mr_request.setAttribute(GSXML.LANG_ATT, request.getAttribute(GSXML.LANG_ATT));
        mr_request.setAttribute(GSXML.TO_ATT, to);
        
        Element mr_response = (Element)mr_.process(mr_message);
        
        // create the return page tree
        Element page = doc_.createElement(GSXML.PAGE_ELEM);
        page.setAttribute(GSXML.LANG_ATT, request.getAttribute(GSXML.LANG_ATT));
        // add the lang stuff from message
        page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, GSXML.DISPLAY_ELEM), true));
        // add the config stuff from message
        page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, GSXML.CONFIGURATION_ELEM), true));
        
        page.appendChild(doc_.importNode(request, true));

        // add in the applet info
        String path = GSXML.RESPONSE_ELEM;
        path = GSPath.appendLink(path, GSXML.SERVICE_ELEM);
        path = GSPath.appendLink(path, GSXML.APPLET_ELEM);
        Element app_desc = (Element)doc_.importNode(GSXML.getNodeByPath(mr_response, path), true);
        // must handle any params that have values that are not 
        // necessarily known by the service
        editLocalParams(app_desc, config_.library_name_, collection);
        page.appendChild(app_desc);

        // process using the stylesheet
        Document style_doc = converter_.getDOM(new File(stylesheet));
        GSXSLT.absoluteIncludePaths(style_doc, config_);
        return (Element)transformer_.transform(style_doc, page);    

    }
    else if (request_type.equals("r")) {
        // we are processing stuff for the applet send a message to the service, type="query", and take out the something element, and return that as our result - the applet must take xml

        Element mr_message = doc_.createElement(GSXML.MESSAGE_ELEM);
        Element mr_request = doc_.createElement(GSXML.REQUEST_ELEM);
        mr_message.appendChild(mr_request);
        mr_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_QUERY);
        mr_request.setAttribute(GSXML.TO_ATT, to);
        mr_request.setAttribute(GSXML.LANG_ATT, request.getAttribute(GSXML.LANG_ATT));

        // just append the params for now
        mr_request.appendChild(doc_.importNode(cgi_param_list, true));
        
        Element mr_response = (Element)mr_.process(mr_message);
        // add in the applet data
        String path = GSXML.RESPONSE_ELEM;
        path = GSPath.appendLink(path, GSXML.APPLET_DATA_ELEM);
        Element applet_info = (Element)GSXML.getNodeByPath(mr_response, path).getFirstChild();
        return applet_info;

    }
    // should never get here
    return null;
    }

    /** this method looks through the PARAMs of the applet description for 
     * one with the name 'library'. If its found, it sets the value to be 
     * library_name
     */
    protected void editLocalParams(Element description, String library_name,
                   String full_collection_name) {

    Node child = description.getFirstChild();
    while (child != null) {
        if (child.getNodeType() == Node.ELEMENT_NODE) {
        String param = child.getNodeName();
        if (param.equals("PARAM")||param.equals("param")) {
            String name = ((Element)child).getAttribute("NAME");
            if (name == null || name.equals("")) {
            // somethings wrong!!
            } else if (name.equals("library")) {
            ((Element)child).setAttribute("VALUE", library_name);
            } else if (name.equals("collection")) {
            ((Element)child).setAttribute("VALUE", full_collection_name);
            }
            
        }
        }
        child = child.getNextSibling();
    }
    }
    
}