source: trunk/gsdl3/src/java/org/greenstone/gsdl3/action/Action.java@ 5407

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.Element; 
import org.w3c.dom.Document; 

// other java stuff
import java.io.File;
import java.util.Vector;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;

/** base class for Actions */
abstract public class Action {

    /** the system set up variables */
    protected HashMap config_params = null;
    /** container Document to create XML Nodes */
    protected Document doc=null; 
    /** a converter class to parse XML and create Docs */
    protected XMLConverter converter=null;
    /** a reference to the message router that it must talk to to
     * get info. it may be a communicator acting as a proxy, but it 
     doesn't care about that */
    protected ModuleInterface mr=null;

    public Action() {
    this.converter = new XMLConverter();
    this.doc = this.converter.newDOM();
    }
    /** the config variables must be set before configure is called */
    public void setConfigParams(HashMap params) {
    this.config_params = params;
    }
    /** sets the message router */
    public void setMessageRouter(ModuleInterface m) {
       this.mr = m;
    }
    public void configure() {
    // does nothing yet
    }
    
    /** process takes an xml representation of cgi args
     * and returns the page of results - may be in html/xml/other
     * depending on the output att of the request */
    public String process(String xml_in) {
       
    Element message = this.converter.getDOM(xml_in).getDocumentElement();
    
    Element result = process(message);
    return this.converter.getString(result);
    }
    
    /** the main process method - must be implemented in subclass */
    abstract public Element process(Element xml_in);

    /** tell the param class what its arguments are 
     * if an action has its own arguments, this should add them to the params
     * object - particularly important for args that should not be saved */
    public boolean getActionParameters(GSParams params) {
    return true;
    }

    protected void extractMetadataNames(Element format, HashSet meta_names) {
    //NodeList nodes = format.getElementsByTagNameNS("metadata", "http://www.greenstone.org/configformat");
    NodeList nodes = format.getElementsByTagName("gsf:metadata");
        for (int i=0; i<nodes.getLength(); i++) {
        String name = ((Element)nodes.item(i)).getAttribute("name");
        String select = ((Element)nodes.item(i)).getAttribute("select");
        if (select.equals("")) {
        meta_names.add(name);
        } else if (select.equals("ancestors")) {
        String separator = ((Element)nodes.item(i)).getAttribute("separator");
        meta_names.add("ancestors'"+separator+"'_"+name);
        } else {
        meta_names.add(select+"_"+name);
        }      
        
        }
    }

    protected Element createMetadataParamList(HashSet metadata_names) {
    Element param_list  = this.doc.createElement(GSXML.PARAM_ELEM+GSXML.LIST_MODIFIER);
    
    Element param = null;
    Iterator i = metadata_names.iterator();
    while (i.hasNext()) {
        String name = (String)i.next();
        param = this.doc.createElement(GSXML.PARAM_ELEM);
        param_list.appendChild(param);
        param.setAttribute(GSXML.NAME_ATT, "metadata");
        param.setAttribute(GSXML.VALUE_ATT, name);
    
    }
    return param_list;
    }

}