source: main/trunk/greenstone3/src/java/org/greenstone/gsdl3/action/Action.java@ 32549

package org.greenstone.gsdl3.action;

import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;

import org.apache.log4j.Logger;
import org.greenstone.gsdl3.core.ModuleInterface;
import org.greenstone.gsdl3.util.Dictionary;
import org.greenstone.gsdl3.util.GSConstants;
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.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

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

    /** the system set up variables */
    protected HashMap<String, Object> config_params = null;
    
  /** the xml element languageList */
  protected Element language_list = null;
    /** a converter class to parse XML and create Docs */
    protected XMLConverter converter = null;
  /** a transformer class in case the action wants to run XSLT itself */
  protected XMLTransformer transformer = 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;

    static Logger logger = Logger.getLogger(org.greenstone.gsdl3.action.Action.class.getName());

    public Action()
    {
        this.converter = new XMLConverter();
        this.transformer = new XMLTransformer();
    }

    /** the config variables must be set before configure is called */
    public void setConfigParams(HashMap<String, Object> params)
    {
        this.config_params = params;
    }

    /** sets the message router */
    public void setMessageRouter(ModuleInterface m)
    {
        this.mr = m;
    }

  /** give the action access to the list of languages */
  public void setLanguageList(Element lang_list) {
    this.language_list = lang_list;
  }
    public boolean configure()
    {
        // does nothing yet
        return true;
    }

    /**
     * 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)
    {

        Document message_doc = this.converter.getDOM(xml_in);
        if (message_doc == null)
        {
            logger.error("Couldn't parse request");
            logger.error(xml_in);
            return null;
        }
        Node result = process(message_doc);
        return this.converter.getString(result);
    }

    /** the main process method - must be implemented in subclass */
    abstract public Node process(Node 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 need to be saved to the session
     */
    public boolean addActionParameters(GSParams params)
    {
        return true;
    }

  protected void getRequiredMetadataNames(Element format, HashSet<String> meta_names) {
    GSXSLT.findExtraMetadataNames(format, meta_names);
  }


    protected Element createMetadataParamList(Document doc, HashSet<String> metadata_names)
    {
        Element param_list = doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);

        Element param = null;
        Iterator<String> i = metadata_names.iterator();
        while (i.hasNext())
        {
            String name = i.next();
            param = doc.createElement(GSXML.PARAM_ELEM);
            param_list.appendChild(param);
            param.setAttribute(GSXML.NAME_ATT, "metadata");
            param.setAttribute(GSXML.VALUE_ATT, name);

        }
        return param_list;
    }

    protected boolean processErrorElements(Element message, Element page)
    {
        NodeList error_nodes = message.getElementsByTagName(GSXML.ERROR_ELEM);
        if (error_nodes.getLength() == 0)
        {
            return false;
        }
        Document owner = page.getOwnerDocument();
        for (int i = 0; i < error_nodes.getLength(); i++)
        {
            page.appendChild(owner.importNode(error_nodes.item(i), true));
        }
        return true;
    }

    /**
     * Takes an XML element and adds the metadata of the current site to it.
     * Useful for adding the current site's metadata to a response before
     * sending it
     * 
     * @param element
     *            the element to add site metadata to
     * @param lang
     *            the current language
     * @param uid
     *            the current user id
     */
    protected void addSiteMetadata(Element element, UserContext userContext)
    {
        Document doc = element.getOwnerDocument();
        
        //ADD SITE METADATA
        Element metadata_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_DESCRIBE, "", userContext);
        //create the element to put the params in
        Element param_list = doc.createElement(GSXML.PARAM_ELEM + GSXML.LIST_MODIFIER);
        // want to get metadataList and displayItemList
        GSXML.addParameterToList(param_list, GSXML.SUBSET_PARAM , GSXML.METADATA_ELEM + GSXML.LIST_MODIFIER);
        GSXML.addParameterToList(param_list, GSXML.SUBSET_PARAM , GSXML.DISPLAY_TEXT_ELEM  + GSXML.LIST_MODIFIER);
        
        metadata_request.appendChild(param_list);
        //create the message
        Element metadata_message = doc.createElement(GSXML.MESSAGE_ELEM);
        metadata_message.appendChild(metadata_request);
        //get response
        Element metadata_response_message = (Element) this.mr.process(metadata_message);
        //drill down to response
        Element metadata_response = (Element) GSXML.getChildByTagName(metadata_response_message, GSXML.RESPONSE_ELEM);
        //merge in metadata
        // *************** need to merge the displayItem lists too
        GSXML.mergeMetadataLists(element, metadata_response);
        GSXML.mergeSpecifiedLists(element, metadata_response, GSXML.DISPLAY_TEXT_ELEM);
    }

    protected void addInterfaceOptions(Element elem)
    {
        Document doc = elem.getOwnerDocument();
        
        Element documentOptionList = doc.createElement("interfaceOptions");
        for (Object key : this.config_params.keySet())
        {
            Element option = doc.createElement("option");
            option.setAttribute(GSXML.NAME_ATT, (String) key);
            option.setAttribute(GSXML.VALUE_ATT, this.config_params.get(key).toString());
            documentOptionList.appendChild(option);
        }
        elem.appendChild(elem.getOwnerDocument().importNode(documentOptionList, true));
    }

    protected Element getFormatInfo(String to, UserContext userContext)
    {
        // Eclipse call hierarchy shows the element returned from this method is 
        // subsequently used in a 'importNode'.  For this reason it is safe here
        // for call up our own document DOM.  
        //
        // If this pattern changes for any reason, then the DOM will need to be
        // passed in as a parameter
        
        Document doc = XMLConverter.newDOM();
        
        Element mr_format_message = doc.createElement(GSXML.MESSAGE_ELEM);
        Element mr_format_request = GSXML.createBasicRequest(doc, GSXML.REQUEST_TYPE_FORMAT, to, userContext);
        mr_format_message.appendChild(mr_format_request);

        // process the message
        Element mr_response_message = (Element) this.mr.process(mr_format_message);
        // the response

        Element format_response = (Element) GSXML.getChildByTagName(mr_response_message, GSXML.RESPONSE_ELEM);

        Element format_elem = (Element) GSXML.getChildByTagName(format_response, GSXML.FORMAT_ELEM);
        if (format_elem != null)
        {
            Element global_format_elem = (Element) GSXML.getChildByTagName(format_response, GSXML.GLOBAL_FORMAT_ELEM);
            if (global_format_elem != null)
            {
                GSXSLT.mergeFormatElements(format_elem, global_format_elem, false);
            }
        }
        return format_elem;
    }

    protected String getTextString(String key, String lang, String dictionary, String[] args)
    {
      logger.error("lang = "+lang);
        if (dictionary != null)
        {
            // just try the one specified dictionary
          Dictionary dict = new Dictionary(dictionary, lang);
            String result = dict.get(key, args);
            if (result == null)
            { // not found
                return "_" + key + "_";
            }
            return result;
        }

        // otherwise we try class names for dictionary names
        String class_name = this.getClass().getName();
        class_name = class_name.substring(class_name.lastIndexOf('.') + 1);
        Dictionary dict = new Dictionary(class_name, lang);
        String result = dict.get(key, args);
        if (result != null)
        {
            return result;
        }

        // we have to try super classes
        Class c = this.getClass().getSuperclass();
        while (result == null && c != null)
        {
            class_name = c.getName();
            class_name = class_name.substring(class_name.lastIndexOf('.') + 1);
            if (class_name.equals("ServiceRack"))
            {
                // this is as far as we go
                break;
            }
            dict = new Dictionary(class_name, lang);
            result = dict.get(key, args);
            c = c.getSuperclass();
        }
        if (result == null)
        {
            return "_" + key + "_";
        }
        return result;

    }

}