source: trunk/gsdl3/src/java/org/greenstone/gsdl3/action/AppletAction.java@ 4144

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) {
    
    Element request = (Element)GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
    
    // get the collection and service params
    Element cgi_param_list = (Element)GSXML.getChildByTagName(request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    HashMap params = GSXML.extractParams(cgi_param_list, false);

    // request_type is display (d) or request (r)
    String request_type = (String)params.get(GSCGI.REQUEST_TYPE_ARG);
    if (!request_type.equals("d")&&!request_type.equals("r")) {
        System.err.println("AppletAction Error: the rt arg should be either d or r, instead it was "+request_type+"!");
        return null;
    }
    
    String collection = (String)params.get(GSCGI.COLLECTION_ARG);
    boolean coll_specified = true;
    String service_name=(String)params.get(GSCGI.SERVICE_ARG);
    String lang = request.getAttribute(GSXML.LANG_ATT);
    String to=null;
    if (collection==null||collection.equals("") ) {
        coll_specified = false;
        to = service_name;
    } else {
        to = GSPath.appendLink(collection, service_name);
    }

    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 = GSXML.createBasicRequest(doc_, GSXML.REQUEST_TYPE_PROCESS, to, lang); 
        mr_message.appendChild(mr_request);
        // just append all the params for now - should filter out unneeded ones
        mr_request.appendChild(doc_.importNode(cgi_param_list, true));
       
        // process the request
        Element mr_response = (Element)mr_.process(mr_message);
        // get the applet data out and pass it back as is. 
        String path = GSPath.appendLink(GSXML.RESPONSE_ELEM, GSXML.APPLET_DATA_ELEM);
        Element applet_info = (Element)GSXML.getNodeByPath(mr_response, path).getFirstChild();
        return applet_info;
        
    }
    
    // else request type  = 'd'
    // find the stylesheet
    String stylesheet = GSFile.stylesheetFile(config_, "applet.xsl");
    
    if (stylesheet==null) {
        System.err.println("AppletAction Error: applet stylesheet not found!");
        return null;
    }
 
    // we are just displaying the applet - get the description from
    // the service, and process using xslt
    
    
    // create the return page tree
    Element page = doc_.createElement(GSXML.PAGE_ELEM);
    page.setAttribute(GSXML.LANG_ATT, lang);
    // add the page extra stuff from message
    page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, GSXML.PAGE_EXTRA_ELEM), true));

    // add in the page Request
    Element page_request = GSXML.duplicateWithNewName(doc_, request, "pageRequest", true);
    page.appendChild(page_request);

    // get the applet description, and the collection info if a collection is specified

    Element mr_message = doc_.createElement(GSXML.MESSAGE_ELEM);
    Element applet_request = GSXML.createBasicRequest(doc_, GSXML.REQUEST_TYPE_DESCRIBE, to, lang); 
    mr_message.appendChild(applet_request);

    if (coll_specified) {
        Element coll_request = GSXML.createBasicRequest(doc_, GSXML.REQUEST_TYPE_DESCRIBE, collection, lang); 
        mr_message.appendChild(coll_request);
    }
    
    Element mr_response = (Element)mr_.process(mr_message);
        
    Element page_response = doc_.createElement(GSXML.PAGE_RESPONSE_ELEM);
    page.appendChild(page_response);
    // add in the applet info
    String path = GSPath.appendLink(GSXML.RESPONSE_ELEM, 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_response.appendChild(app_desc);
    
    if (coll_specified) {
        Element coll_response = (Element) mr_response.getElementsByTagName(GSXML.RESPONSE_ELEM).item(1);
        Element coll_elem = (Element)GSXML.getChildByTagName(coll_response, GSXML.COLLECTION_ELEM);
        page_response.appendChild(doc_.importNode(coll_elem, true));
    }
    
    // process using the stylesheet
    Document style_doc = converter_.getDOM(new File(stylesheet));
    GSXSLT.absoluteIncludePaths(style_doc, config_);
    return (Element)transformer_.transform(style_doc, page);    
    
    }

    /** this method looks through the PARAMs of the applet description for 
     * 'library' or 'collection'. If found, the params are set to  
     * the appropriate values 
     */
    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();
    }
    }
    
}