code: /**
   * Copyright 2012 Lezan Hawizy, David M. Jessop, Daniel Lowe and Peter Murray-Rust
   *
   * 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 uk.ac.cam.ch.wwmm.chemicaltagger;
  
  import java.util.ArrayList;
  import java.util.List;
  
  import nu.xom.Document;
  import nu.xom.Element;
  import nu.xom.Text;
  
  import org.antlr.v4.runtime.ParserRuleContext;
  
  
  /*****************************
   * Converts ANTLR ASTTrees into XML Documents.
   * 
   * @author lh359
   *****************************/
  
  public class XMLtoAST {
  
  	private List<String> SentenceList;
  	private ParserRuleContext parseTree;	
  
  	public XMLtoAST() {
  		SentenceList = new ArrayList<String>();
  	}
  
  	/********************************************
  	 * Converts AST Trees to XML Document.
  	 * 
  	 * @param doc (Document)
  	 * @return doc (Document)
  	 *******************************************/
  	public Document convert(Document doc) {
  		
  	 	parseTree = new ParserRuleContext();
  		SentenceList = new ArrayList<String>();
  		getNodes(doc.getRootElement(), parseTree);
  
  		return doc;
  	}
  
  	public String getStringTree() {
  		return parseTree.toStringTree();
  	}
  
  	public List<String> getSentenceList() {
  		return SentenceList;
  	}
  
  	/**********************************************
  	 * A recursive function that goes through the leaves of the tree to create
  	 * XML nodes.
  	 * 
  	 * @param docElement (Element)
  	 * @param treeNode (ParserRuleContext)
  	 **********************************************/
  	public void getNodes(Element docElement, ParserRuleContext treeNode) {
  
  		int nodeCount = docElement.getChildCount();
  
  		for (int i = 0; i < nodeCount; i++) {
  			if (docElement.getChild(i) instanceof Text) {
  				//treeNode.addChild(new ParserRuleContext(docElement.getChild(i).getValue()));
  				treeNode.addChild(new ParserRuleContext());
  			}
  
  			else {
  				Element docChild = (Element) docElement.getChild(i);
  				String name = docChild.getLocalName();
  
  				if (docChild.getAttribute("type") != null) {
  					name = docChild.getLocalName() + "_"
  							+ docChild.getAttributeValue("type");
  				}
  				ParserRuleContext subTree = new ParserRuleContext();
  				treeNode.addChild(subTree);
  
  				getNodes(docChild, subTree);
  				if (name.startsWith("Sentence")
  						&& !(docChild.toXML().contains("Unmatched"))) {
  					SentenceList.add(subTree.toStringTree());
  				}
  
  			}
  		}
  
  	}
  
  }
  