LODEParser.java

/*
 * Copyright 2012-2013 Ontology Engineering Group, Universidad Politécnica de Madrid, Spain
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package widoco;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.StringWriter;
import java.util.HashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

/**
 * Class made for parsing and manipulating LODE's html.
 * This class contains most of the TemplateGeneratorOLD class
 * @author Daniel Garijo
 */
public class LODEParser {
    private final HashMap<String,String> replacements; //replace lode's ids with the classes and properties.
    //this will allow navigating the document properly. It might be troublesome if a class is names as a prop.
    private String classes;
    private String classList;
    private String properties;
    private String propertyList;
    private String dataProp;
    private String dataPropList;
    private final HashMap <String,String> namespaceDeclarations;
    Configuration c;

//    public LODEParser() {
//        replacements = new HashMap<String, String>();
//    }
    /**
     * Constructor for the lode parser. The reason for creating this class is that
     * I don't want to edit LODE's xls file, and I only want to reuse certain parts.
     * @param lodeContent text obtained as a response from LODE.
     */
    public LODEParser(String lodeContent, Configuration c) {
        replacements = new HashMap<String, String>();
        namespaceDeclarations = new HashMap<String, String>();
        this.c = c;
        parse(lodeContent);
    }

    public String getClassList() {
        return classList;
    }

    public String getClasses() {
        return classes;
    }

    public String getDataProp() {
        return dataProp;
    }

    public String getDataPropList() {
        return dataPropList;
    }

    public String getProperties() {
        return properties;
    }

    public String getPropertyList() {
        return propertyList;
    }

    public HashMap<String, String> getNamespaceDeclarations() {
        return namespaceDeclarations;
    }
    
    private void parse(String content){
        try {            
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();                    
            Document doc = db.parse(new ByteArrayInputStream(content.getBytes("UTF-8")));//StandardCharsets.UTF_8

            NodeList html = doc.getElementsByTagName("div");
//            String cList = "", pList= "", dPList= "", c= "", p= "", dp="";
            for(int i = 0; i<html.getLength();i++){
                String attrID = html.item(i).getAttributes().item(0).getTextContent();
                if(attrID.equals("classes")){
                    classList = getTermList(html.item(i));
                    classes = nodeToString(html.item(i));
                }
                else if(attrID.equals("objectproperties")){
                    propertyList =getTermList(html.item(i));
                    properties = (nodeToString(html.item(i)));
                }
                else if(attrID.equals("dataproperties")){
                    dataPropList = (getTermList(html.item(i)));
                    dataProp = (nodeToString(html.item(i)));
                }
                else if(attrID.equals("namespacedeclarations")){
                    Node namespace = html.item(i);
                    //<dt> prefix </dt> <dd>namespace</dd>
                    try{
                        NodeList dl = namespace.getChildNodes().item(1).getChildNodes();//first node is h2. second is dl
                        int j = 0;
                        while(j<dl.getLength()){
                            String key = dl.item(j).getTextContent();
                            if(dl.item(j).getNodeName().equals("dt")){
                                String value = dl.item(j+1).getTextContent();
                                //System.out.println(key+","+value);
                                namespaceDeclarations.put(key,value);
                            }
                            j++;
                        }
                    }catch(Exception e){
                        System.err.println("Error while retrieving the namespaces from LODE");
                    }
                    
                }
            }
            //fix ids
            if(!"".equals(classList)&&classList!=null){
                classList = fixIds(classList);
                classes = fixIds(classes);
            }
            if(!"".equals(propertyList) &&propertyList!=null){
                propertyList = fixIds(propertyList);
                properties = fixIds(properties);
            }
            if(!"".equals(dataPropList)&& dataPropList!=null){
                dataPropList = fixIds(dataPropList);
                dataProp = fixIds(dataProp);
            }                                       
            System.out.println("Parsing Complete!");
        } catch (ParserConfigurationException ex) {
            System.out.println("Exception interpreting the resource: "+ ex.getMessage());
        } catch (DOMException ex) {
            System.out.println("Exception interpreting the resource: "+ ex.getMessage());
        } catch (SAXException ex) {
            Logger.getLogger(LODEParser.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(LODEParser.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    
    private  String getTermList(Node n){
    NodeList divs = n.getChildNodes();
    for(int j = 0; j<divs.getLength(); j++){
        if(divs.item(j).getNodeName().equals("ul")){            
            return(nodeToString(divs.item(j)));
        }       
    }    
    return null;
}    
    private  String nodeToString(Node n){
        try {
            TransformerFactory transfac = TransformerFactory.newInstance();
            Transformer trans = transfac.newTransformer();
            trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
            trans.setOutputProperty(OutputKeys.INDENT, "yes");
            StringWriter sw = new StringWriter();
            StreamResult result = new StreamResult(sw);
            DOMSource source = new DOMSource(fixAnchor(n));
            trans.transform(source, result);
            return sw.toString();
//            String returnValue= sw.toString().replace("\n", "");          
//            return(returnValue);
        }
        catch (IllegalArgumentException ex) {
            System.err.println("Error while writing to xml "+ex.getMessage());
            //ex.printStackTrace();
            return null;
        } catch (TransformerException ex) {
            System.err.println("Error while writing to xml "+ex.getMessage());
            //ex.printStackTrace();
            return null;
        }
    }

    //this methods removes the first 2 anchors of the div returned by LODE (they lead to an error).
    //it also changes the id of the div replacing it with the name found in the anchor
    //(the second one)
    private  Node fixAnchor(Node nodeToFix) {        
        try{
            NodeList outerDiv = nodeToFix.getChildNodes();
            for(int i = 0; i<outerDiv.getLength(); i++){
                Node currentNode = outerDiv.item(i);
                if(currentNode.getNodeName().equals("div")){
                    //NodeList list =  nodeToFix.getChildNodes();
                    Node firstAnchor = currentNode.getFirstChild();
                    Node secondAnchor = firstAnchor.getNextSibling();
                    String newID = firstAnchor.getAttributes().getNamedItem("name").getNodeValue();
                    newID = newID.replace(c.getMainOntology().getNamespaceURI(), "");
                    if(secondAnchor.getNodeName().equals("a")){
                        currentNode.removeChild(secondAnchor);
                    }
                    //we save the the id for derreferencing properly the resource. Note that
                    //if a property has the same name as a Class this could lead to problems                
                    replacements.put(currentNode.getAttributes().getNamedItem("id").getNodeValue(), newID);

                    //we remove the anchor, which make an error in the visualization
                    currentNode.removeChild(firstAnchor);
                }
            }
            return nodeToFix;
        }catch(DOMException ex){
            System.err.println("Could not fix node");
            return nodeToFix;
        }
    }
    
    /**
     * Method to fix the ids generated automatically by LODE with the URIs of the classes and properties.
     * @param textToBeFixed The input text with the links to be fixed
     * @return 
     */
    private String fixIds(String textToBeFixed){    
        for (String keyToReplace : replacements.keySet()) {
            textToBeFixed = textToBeFixed.replace(keyToReplace, replacements.get(keyToReplace));
            textToBeFixed = textToBeFixed.replace("<span>:", "<span>");
        }
        return textToBeFixed;
    }
}