MethodDefinitionsDeserializer.java

/* The contents of this file are subject to the license and copyright terms
 * detailed in the license directory at the root of the source tree (also 
 * available online at http://fedora-commons.org/license/).
 */
package fedora.client.objecteditor.types;

import java.io.IOException;
import java.io.InputStream;

import java.util.ArrayList;
import java.util.List;

import javax.xml.parsers.SAXParser;
import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.DefaultHandler;

/**
 * Turns xml for method defs into java object instances.
 */
class MethodDefinitionsDeserializer
        extends DefaultHandler {

    /** The deserialized MethodDefinition objects */
    private final List m_result;

    // values gathered and built while parsing
    private String m_methodName;

    private String m_methodLabel;

    private List m_methodParms;

    private String m_parmName;

    private String m_parmLabel;

    private String m_parmRequired;

    private String m_parmDefaultValue;

    private List m_parmValidValues;

    public MethodDefinitionsDeserializer(InputStream xml)
            throws IOException {
        m_result = new ArrayList();
        try {
            SAXParserFactory spf = SAXParserFactory.newInstance();
            spf.setNamespaceAware(true);
            SAXParser parser = spf.newSAXParser();
            parser.parse(xml, this);
        } catch (Exception e) {
            if (e.getMessage() != null) {
                throw new IOException(e.getMessage());
            } else {
                throw new IOException("Error parsing method definitions: "
                        + e.getClass().getName());
            }
        }
    }

    public List getResult() {
        return m_result;
    }

    @Override
    public void startElement(String uri,
                             String localName,
                             String qName,
                             Attributes a) {
        if (localName.equals("Method")) {
            m_methodName = null;
            m_methodLabel = null;
            m_methodParms = new ArrayList();
            for (int i = 0; i < a.getLength(); i++) {
                String name = a.getLocalName(i);
                if (name.equals("operationName")) {
                    m_methodName = a.getValue(i);
                } else if (name.equals("label")) {
                    m_methodLabel = a.getValue(i);
                }
            }
        } else if (localName.equals("UserInputParm")) {
            m_parmName = null;
            m_parmLabel = null;
            m_parmRequired = null;
            m_parmDefaultValue = null;
            m_parmValidValues = new ArrayList();
            for (int i = 0; i < a.getLength(); i++) {
                String name = a.getLocalName(i);
                if (name.equals("parmName")) {
                    m_parmName = a.getValue(i);
                } else if (name.equals("label")) {
                    m_parmLabel = a.getValue(i);
                } else if (name.equals("required")) {
                    m_parmRequired = a.getValue(i);
                } else if (name.equals("defaultValue")) {
                    m_parmDefaultValue = a.getValue(i);
                }
            }
        } else if (localName.equals("ValidParm")) {
            for (int i = 0; i < a.getLength(); i++) {
                String name = a.getLocalName(i);
                if (name.equals("value")) {
                    m_parmValidValues.add(a.getValue(i));
                }
            }
        }
    }

    @Override
    public void endElement(String uri, String localName, String qName)
            throws SAXException {
        if (localName.equals("UserInputParm")) {
            if (m_parmName == null || m_parmName.length() == 0) {
                throw new SAXException("UserInputParm must have a name "
                        + "attribute with length>1.");
            }
            boolean parmRequired = false;
            if (m_parmRequired != null) {
                if (m_parmRequired.equalsIgnoreCase("true")
                        || m_parmRequired.equalsIgnoreCase("yes")
                        || m_parmRequired.equals("1")) {
                    parmRequired = true;
                }
            }
            m_methodParms.add(new ParameterDefinition(m_parmName,
                                                      m_parmLabel,
                                                      parmRequired,
                                                      m_parmDefaultValue,
                                                      m_parmValidValues));
        } else if (localName.equals("Method")) {
            if (m_methodName == null || m_methodName.length() == 0) {
                throw new SAXException("Method must have a name attribute "
                        + "with length>1.");
            }
            m_result.add(new MethodDefinition(m_methodName,
                                              m_methodLabel,
                                              m_methodParms));
        }
    }
}