XPathExpr.java

package org.tigris.juxy.xpath;

import org.w3c.dom.Node;

import java.util.List;

/**
 * Simple XPath expressions evaluator. You can evaluate XPath expression to string, int, double, boolean, nodeset or node.
 *
 * @author Pavel Sher
 */
public interface XPathExpr {
  /**
   * Registers new namespace in the XPath expression context. Function returns the same XPathExpr object.
   *
   * @param prefix namespace prefix
   * @param uri    namespace uri
   * @return XPathExpr object
   * @throws XPathExpressionException thrown if an error occured
   */
  XPathExpr addNamespace(String prefix, String uri) throws XPathExpressionException;

  /**
   * Evaluates expression and converts result to boolean.
   *
   * @param node the node on which evaluation is performed.
   * @return boolean result of XPath expression
   * @throws XPathExpressionException thrown if error occured during XPath evaluation
   */
  boolean toBoolean(Node node) throws XPathExpressionException;

  /**
   * Evaluates expression and converts result to string.
   *
   * @param node the node on which evaluation is performed
   * @return string result of XPath expression
   * @throws XPathExpressionException thrown if error occured during XPath evaluation
   */
  String toString(Node node) throws XPathExpressionException;

  /**
   * Evaluates expression and converts result to int.
   *
   * @param node the node on which evaluation is performed
   * @return int result of XPath expression
   * @throws XPathExpressionException thrown if error occured during XPath evaluation
   */
  int toInt(Node node) throws XPathExpressionException;

  /**
   * Evaluates expression and converts result to double.
   *
   * @param node the node on which evaluation is performed
   * @return double result of XPath expression
   * @throws XPathExpressionException thrown if error occured during XPath evaluation
   */
  double toDouble(Node node) throws XPathExpressionException;

  /**
   * Evaluates expression and conveerts result to a set of nodes.
   *
   * @param node the node on which evaluation is performed
   * @return a collection of nodes
   * @throws XPathExpressionException thrown if error occurs during XPath evaluation
   */
  List toNodeList(Node node) throws XPathExpressionException;

  /**
   * Evaluates expression and returns node as its result.
   *
   * @param node the node on which evaluation is performed
   * @return a node
   * @throws XPathExpressionException thrown if error occurs during XPath evaluation
   */
  Node toNode(Node node) throws XPathExpressionException;

  /**
   * Converts this XPath expression to string
   *
   * @return expression
   */
  String getExpression();
}