source: trunk/gli/src/org/greenstone/gatherer/metadata/MetadataSet.java@ 8164

/**
 *############################################################################
 * A component of the Greenstone Librarian Interface, part of the Greenstone
 * digital library suite from the New Zealand Digital Library Project at the
 * University of Waikato, New Zealand.
 *
 * Author: Michael Dewsnip, NZDL Project, University of Waikato, NZ
 *
 * Copyright (C) 2004 New Zealand Digital Library Project
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *############################################################################
 */

package org.greenstone.gatherer.metadata;


import java.io.*;
import java.util.*;
import org.greenstone.gatherer.util.XMLTools;
import org.w3c.dom.*;


/** This class represents one metadata set */
public class MetadataSet
{
    private File metadata_set_file = null;
    private ArrayList metadata_set_elements = new ArrayList();
    private String metadata_set_namespace = null;


    public MetadataSet(File metadata_set_file)
    {
    this.metadata_set_file = metadata_set_file;

    // Parse the specified metadata set file
    Document document = XMLTools.parseXMLFile(metadata_set_file);
    if (document == null) {
        System.err.println("Error: Could not parse metadata set file " + metadata_set_file.getAbsolutePath());
        return;
    }

    // Read the metadata set's namespace
    metadata_set_namespace = document.getDocumentElement().getAttribute("namespace");

    // Read the Element elements in the metadata set
    NodeList element_elements_nodelist = document.getElementsByTagName("Element");
    for (int i = 0; i < element_elements_nodelist.getLength(); i++) {
        Element metadata_element_element = (Element) element_elements_nodelist.item(i);
        String metadata_element_name = metadata_element_element.getAttribute("name");
        String metadata_element_name_full = metadata_set_namespace + MetadataTools.NAMESPACE_SEPARATOR + metadata_element_name;
        metadata_set_elements.add(new MetadataElement(metadata_element_name_full, metadata_element_element));
    }
    }


    public MetadataElement addMetadataElementForThisSession(String metadata_element_name)
    {
    String metadata_element_name_full = metadata_set_namespace + MetadataTools.NAMESPACE_SEPARATOR + metadata_element_name;
    MetadataElement metadata_element = new MetadataElement(metadata_element_name_full, null);
    metadata_set_elements.add(metadata_element);
    return metadata_element;
    }


    public int compareMetadataElements(MetadataElement metadata_element_a, MetadataElement metadata_element_b)
    {
    // Extracted metadata is sorted alphabetically
    if (metadata_set_namespace.equals(MetadataSetManager.EXTRACTED_METADATA_NAMESPACE)) {
        return metadata_element_a.getName().compareTo(metadata_element_b.getName());
    }

    // Elements in metadata sets are sorted according to the other they are specified in the .mds file
    return metadata_set_elements.indexOf(metadata_element_a) - metadata_set_elements.indexOf(metadata_element_b);
    }


    public String getAttribute(String attribute_name, String language_code)
    {
    // Parse the specified metadata set file
    Document document = XMLTools.parseXMLFile(metadata_set_file);
    if (document == null) {
        System.err.println("Error: Could not parse metadata set file " + metadata_set_file.getAbsolutePath());
        return null;
    }

    Element document_element = document.getDocumentElement();
    Element parent_element = document_element;
    boolean language_matches = false;

    NodeList setlanguage_elements_nodelist = document_element.getElementsByTagName("SetLanguage");
    for (int i = 0; i < setlanguage_elements_nodelist.getLength(); i++) {
        Element current_setlanguage_element = (Element) setlanguage_elements_nodelist.item(i);
        String current_setlanguage_element_code = current_setlanguage_element.getAttribute("code");
        if (current_setlanguage_element_code.equals(language_code)) {
        // Found language; use it for the next step
        parent_element = current_setlanguage_element;
        language_matches = true;
        break;
        }
    }

    NodeList attribute_elements_nodelist = parent_element.getElementsByTagName(attribute_name);
    for (int i = 0; i < attribute_elements_nodelist.getLength(); i++) {
        Element current_attribute_element = (Element) attribute_elements_nodelist.item(i);

        // Check if the language matches
        String current_attribute_element_language = current_attribute_element.getAttribute("language");
        if (language_matches || current_attribute_element_language.equals(language_code)) {
        // Found attribute; returns its value
        return XMLTools.getElementTextValue(current_attribute_element);
        }
    }

    return null;
    }


    public MetadataElement getMetadataElementWithDisplayName(String metadata_element_display_name_full)
    {
    // Find the desired metadata element in the list
    for (int i = 0; i < metadata_set_elements.size(); i++) {
        MetadataElement metadata_element = (MetadataElement) metadata_set_elements.get(i);
        if (metadata_element.getDisplayName().equals(metadata_element_display_name_full)) {
        return metadata_element;
        }
    }

    // Not found
    return null;
    }


    public MetadataElement getMetadataElementWithName(String metadata_element_name)
    {
    // Find the desired metadata element in the list
    for (int i = 0; i < metadata_set_elements.size(); i++) {
        MetadataElement metadata_element = (MetadataElement) metadata_set_elements.get(i);
        if (metadata_element.getName().equals(metadata_element_name)) {
        return metadata_element;
        }
    }

    // Not found
    return null;
    }


    public ArrayList getMetadataSetElements()
    {
    // We don't want anyone to modify the list, so return a copy of it
    return (ArrayList) metadata_set_elements.clone();
    }


    public File getMetadataSetFile()
    {
    return metadata_set_file;
    }


    public String getNamespace()
    {
    return metadata_set_namespace;
    }
}