package at.gv.egovernment.moa.spss.api.common;

import java.util.Map;

/**
 * An XPath expression set operation.
 * 
 * @author Patrick Peck
 * @version $Id$
 */
public interface XPathFilter {
  /** Subtract this filter's node set from the resulting node set. */
  public static final String SUBTRACT_TYPE = "subtract";
  /** Intersect this filter's node set with the resulting node set. */
  public static final String INTERSECT_TYPE = "intersect";
  /** Compute the union of this filter's node set and the resulting node set. */
  public static final String UNION_TYPE = "union";
  
  /**
   * Gets the type of this <code>XPathFilter</code>.
   * 
   * @return The type of this <code>XPathFilter</code>.
   */
  public String getFilterType();
  /**
   * Gets the XPath expression for selecting the nodes.
   * 
   * @return The XPath expression for selecting the nodes.
   */
  public String getXPathExpression();
  /**
   * Gets The namespace prefix to URI mapping used during evaluation of the
   * XPath expression.
   * 
   * @return The namespace prefix to URI mapping.
   */
  public Map getNamespaceDeclarations();
}