BibtexNode.java

/*
 * Created on Mar 17, 2003
 *
 * @author henkel@cs.colorado.edu
 * 
 */
package bibtex.dom;

import java.io.PrintWriter;
import java.io.StringWriter;

/**
 * An abstract superclass for all bibtex model nodes.
 * 
 * @author henkel
 */
public abstract class BibtexNode {

	/**
	 * Some people have asked why this constructor has a parameter of type BibtexFile (which in turn extends BibtexNode).
	 * The reason is that each BibtexNode has a backpointer to the BibtexFile which it belongs to. Of course, for the
	 * file itself that pointer is null.
	 * 
	 * By the way, it's unlikely that you need to call this constructor or any constructor for BibtexNodes other than
	 * BibtexFile directly - instead, use the BibtexFile as a factory.
	 * 
	 * For example, to create a bibtex file equivalent of this
	 * <pre>
	 * ================
	 * @article{test1,
	 * author="Johannes Henkel",
	 * title="README"
	 * }
	 * ================
	 * you'd do
	 * 
	 * BibtexFile bibtexFile = new BibtexFile();
	 * BibtexEntry onlyEntry = bibtexFile.makeEntry("article","test1");
	 * onlyEntry.setField("author",bibtexFile.makeString("Johannes Henkel"));
	 * onlyEntry.setField("title",bibtexFile.makeString("README"));
	 * </pre>
	 * @param bibtexFile
	 */
	BibtexNode(BibtexFile bibtexFile){
	    
	    assert (this instanceof BibtexFile) || bibtexFile!=null: "bibtexFile parameter may not be null, unless this is a BibtexFile.";
	    
		this.bibtexFile = bibtexFile;
	}

	private final BibtexFile bibtexFile;
	
	public BibtexFile getOwnerFile(){
		return bibtexFile;
	}
	
	abstract public void printBibtex(PrintWriter writer);

	public String toString(){
		StringWriter stringWriter = new StringWriter();
		PrintWriter out = new PrintWriter(stringWriter);
		printBibtex(out);
		out.flush();
		return stringWriter.toString();
	}

}