/*
 * Copyright (c) 1998-2011 Caucho Technology -- all rights reserved
 *
 * This file is part of Resin(R) Open Source
 *
 * Each copy or derived work must preserve the copyright notice and this
 * notice unmodified.
 *
 * Resin Open Source is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * Resin Open Source is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
 * of NON-INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Resin Open Source; if not, write to the
 *   Free SoftwareFoundation, Inc.
 *   59 Temple Place, Suite 330
 *   Boston, MA 02111-1307  USA
 *
 * @author Scott Ferguson
 */

package com.caucho.jstl.el;

import com.caucho.jsp.PageContextImpl;
import com.caucho.xpath.Env;
import com.caucho.xpath.XPath;
import com.caucho.xpath.XPathException;

import org.w3c.dom.Node;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;
import java.util.logging.Level;
import java.util.logging.Logger;

public class XmlSetTag extends TagSupport {
  private static final Logger log
    = Logger.getLogger(XmlSetTag.class.getName());
  private com.caucho.xpath.Expr _select;
  
  private String _var;
  private String _scope;

  /**
   * Sets the JSP-EL expression value.
   */
  public void setSelect(com.caucho.xpath.Expr select)
  {
    _select = select;
  }

  /**
   * Sets the variable to be saved.
   */
  public void setVar(String var)
  {
    _var = var;
  }

  /**
   * Sets the scope of the variable to be saved.
   */
  public void setScope(String scope)
  {
    _scope = scope;
  }

  /**
   * Process the tag.
   */
  public int doStartTag()
    throws JspException
  {
    try {
      PageContextImpl pageContext = (PageContextImpl) this.pageContext;
      
      Object value = evalObject(pageContext, _select);

      CoreSetTag.setValue(pageContext, _var, _scope, value);
    } catch (JspException e) {
      throw e;
    } catch (Exception e) {
      log.log(Level.FINE, e.toString(), e);
    }

    return SKIP_BODY;
  }

  /**
   * Returns the value as an object.
   */
  public static Object evalObject(PageContextImpl pageContext,
                                  com.caucho.xpath.Expr select)
    throws XPathException, JspException
  {
    try {
      Env env = XPath.createEnv();
      env.setVarEnv(pageContext.getVarEnv());
      
      Node node = pageContext.getNodeEnv();
      
      Object value = select.evalObject(node, env);

      env.free();

      return value;
    } catch (javax.el.ELException e) {
      throw new JspException(e);
    }
  }
}