// This file is copyrighted and is part of nzdis-oql package. 
// See the file LICENSE for copyright information and the terms and conditions for copying, distributing and modifications of nzdis-oql package.
// @copyright@

package nzdis.lang.oql;

/**/
import nzdis.lang.oql.analysis.DepthFirstAdapter;
import nzdis.lang.oql.node.*;
import java.util.Hashtable;

/**
 * Represents an utility class via which the node substitution can be
 * easily made.
 * 
 *<br><br>
 * QueryBuilder.java<br>
 * Created: Fri Feb 25 12:30:12 2000<br>
 *
 * @author Mariusz Nowostawski
 * @version @version@ $Revision: 1.1 $
 */
public class QueryBuilder extends DepthFirstAdapter {

  Node ast;
  Hashtable context;

  public QueryBuilder() {
    this.context = new Hashtable();
  }

  public void setContext(Hashtable context){
    this.context = context;
  }

  public void setNode(Node ast){
    this.ast = ast;
  }
  
  /**
   * Returns the string representation of the query. */
  public String getQueryString(){
    final Oql2AsciiWalker w = new Oql2AsciiWalker();
    final OqlOutputStrategyString s = new OqlOutputStrategyString();
    w.setStategy(s);
    w.setContext(this.context);
    ast.apply(w);
    return s.toAscii().toString();
  }
  
} // QueryAnalyser
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