source: trunk/gsdl3/src/java/org/greenstone/gsdl3/action/BrowseAction.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.Document; 
import org.w3c.dom.Element; 

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

/** action for classifier browsing */
public class BrowseAction extends Action {
    
    public Element process (Element message) {

    // get the request - assume only one
    Element request = (Element)GSXML.getChildByTagName(message, GSXML.REQUEST_ELEM);
    
    // 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 system stuff from message
    page.appendChild(doc_.importNode(GSXML.getChildByTagName(message, GSXML.CONFIGURATION_ELEM), true));

    
    // the browse type is the subaction
    String browse_type = request.getAttribute(GSXML.SUBACTION_ATT);
    
    if (browse_type.equals("Classifier")) {
        return classifierBrowse(page, request);
    }
    return unknownBrowse(page, request, browse_type);

    
    }
    

    protected Element classifierBrowse(Element page, Element request) {

    // check that the stylesheet is present - cant output a page without one. we may adapt this to use unknownquery stylesheet? - or ask for one from the MR
    String stylesheet = GSFile.stylesheetFile(config_, "classifier.xsl");
    if (stylesheet==null) {
        System.err.println("BrowseAction Error: classifier stylesheet not found!");
        return null;
    }
    Document style_doc = converter_.getDOM(new File(stylesheet));

    // extract the params from the cgi-request, and check that we have a coll specified
    Element cgi_paramList = (Element)GSXML.getChildByTagName(request, GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    HashMap params = GSXML.extractParams(cgi_paramList);

    String collection = (String)params.get(GSCGI.COLLECTION_ARG);
    if (collection == null || collection.equals("")) {
        System.err.println("BrowseAction Error:classifierbrowse, need to specify a collection!");
        return null;
       
    }


    // get the service info from the MR - this will probably need to be cached somehow later on. 

    Element mr_info_message = doc_.createElement(GSXML.MESSAGE_ELEM);
    Element mr_info_request = doc_.createElement(GSXML.REQUEST_ELEM);
    mr_info_message.appendChild(mr_info_request);
    mr_info_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_DESCRIBE);
    mr_info_request.setAttribute(GSXML.LANG_ATT, request.getAttribute(GSXML.LANG_ATT));

    String to = collection;
    to = GSPath.appendLink(to, "ClassifierBrowse");
    mr_info_request.setAttribute(GSXML.TO_ATT, to);

    Element mr_info_response = (Element) mr_.process(mr_info_message);

    String path = GSXML.RESPONSE_ELEM;
    path = GSPath.appendLink(path, GSXML.SERVICE_ELEM);

    Element description = (Element)doc_.importNode(GSXML.getNodeByPath(mr_info_response, path), true);
    
    // the first part of the data for the page is the cgi-params
    Element cgi_request = (Element)doc_.importNode(request, true);
    page.appendChild(cgi_request);

    page.appendChild(description);
    
    // if there is a cl field in the cgi params, get the classifier info
    String node = (String)params.get("cl");
    
    if (node!=null && !node.equals("")) {

        // get the info for the selected node
        Element mr_query_message = doc_.createElement(GSXML.MESSAGE_ELEM);
        Element mr_query_request = doc_.createElement(GSXML.REQUEST_ELEM);
        mr_query_message.appendChild(mr_query_request);
        
        mr_query_request.setAttribute(GSXML.TYPE_ATT, GSXML.REQUEST_TYPE_QUERY);
        mr_query_request.setAttribute(GSXML.TO_ATT, to);
        mr_query_request.setAttribute(GSXML.LANG_ATT, request.getAttribute(GSXML.LANG_ATT));
        
        
        // paramList - empty for now
        Element paramList = doc_.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
        mr_query_request.appendChild(paramList);
        
        
        // content - contains the classifier node, may be more than one
        // call this document list for now
        Element query_content = doc_.createElement(GSXML.CONTENT_ELEM);
        mr_query_request.appendChild(query_content);
        
        Element document_list = doc_.createElement(GSXML.DOCUMENT_ELEM+GSXML.LIST_MODIFIER);
        Element document = doc_.createElement(GSXML.DOCUMENT_ELEM);
        document.setAttribute(GSXML.NAME_ATT, node);
        document_list.appendChild(document);
        query_content.appendChild(document_list);
        
        Element mr_query_response = (Element)mr_.process(mr_query_message);
        
        Element response = (Element)GSXML.getChildByTagName(mr_query_response, GSXML.RESPONSE_ELEM);
        Node new_style = GSXML.getChildByTagName(response, "stylesheet");
        if (new_style !=null) {
        GSXSLT.mergeStylesheets(style_doc, (Element)new_style);
        response.removeChild(new_style);
        }
        // add the response to the page data
        page.appendChild(doc_.importNode(response, true));

    }
    
    GSXSLT.absoluteIncludePaths(style_doc, config_);
    return (Element)transformer_.transform(style_doc, page);
    }

    protected Element unknownBrowse(Element page, Element request, String browse_type) {
    System.err.println("BrowseAction Error: unknown browse subtype: "+browse_type);
    return null;
    }
}