/*
    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/taglib/ErrorsTag.java,v 1.18 2006/01/13 13:38:51 hkollmann Exp $
    * $Revision: 1.18 $
    * $Date: 2006/01/13 13:38:51 $
    *
    * DbForms - a Rapid Application Development Framework
    * Copyright (C) 2001 Joachim Peer <joepeer@excite.com>
    *
    * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU Lesser General Public
   * License as published by the Free Software Foundation; either
   * version 2.1 of the License, or (at your option) any later version.
   *
   * This library 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.  See the GNU
   * Lesser General Public License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
   */
  
  /*
   * the idea for this class was taken from the class ErrorsTag-class of the Apache Struts Project
   */
  package org.dbforms.taglib;
  
  import org.dbforms.util.MessageResources;
  
  import java.io.IOException;
  
  import java.util.Enumeration;
  import java.util.Vector;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.JspWriter;
  import javax.servlet.jsp.PageContext;
  
  
  
  /***
   * Custom tag that renders error messages if an appropriate request attribute
   * has been created.
   *
   * <p>
   * This idea for this class came from a - much more powerful - class done by
   * Craig R. McClanahan for the Apache struts framework.
   * </p>
   *
   * @author Joe Peer
   */
  public class ErrorsTag extends AbstractScriptHandlerTag
     implements javax.servlet.jsp.tagext.TryCatchFinally {
     private String caption       = "Error:";
     private String messagePrefix;
     private String name = "errors";
  
     /***
      * DOCUMENT ME!
      *
      * @param caption DOCUMENT ME!
      */
     public void setCaption(String caption) {
        this.caption = caption;
     }
  
  
     /***
      * DOCUMENT ME!
      *
      * @return DOCUMENT ME!
      */
     public String getCaption() {
        return (this.caption);
     }
  
  
     /***
      * Insert the method's description here. Creation date: (2001-05-10
      * 12:57:08)
      *
      * @param newMessagePrefix java.lang.String
      */
     public void setMessagePrefix(java.lang.String newMessagePrefix) {
        messagePrefix = newMessagePrefix;
     }
  
  
     /***
      * Insert the method's description here. Creation date: (2001-05-10
      * 12:57:08)
      *
      * @return java.lang.String
      */
     public java.lang.String getMessagePrefix() {
        return messagePrefix;
     }
 
 
    /***
     * DOCUMENT ME!
     *
     * @param name DOCUMENT ME!
     */
    public void setName(String name) {
       this.name = name;
    }
 
 
    /***
     * DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public String getName() {
       return (this.name);
    }
 
 
    /***
     * DOCUMENT ME!
     */
    public void doFinally() {
       messagePrefix = null;
       name          = "errors";
       caption       = "Error:";
    }
 
 
    // ------------------------------------------------------- Public Methods
 
    /***
     * Render the specified error messages if there are any.
     *
     * @return DOCUMENT ME!
     *
     * @exception JspException if a JSP exception has occurred
     */
    public int doStartTag() throws JspException {
       Vector             originalErrors = (Vector) pageContext.getAttribute(getName(),
                                                                             PageContext.REQUEST_SCOPE);
       HttpServletRequest request = (HttpServletRequest) pageContext.getRequest();
 
       if ((originalErrors != null) && (originalErrors.size() > 0)) {
          // Extract out only user defined text
          Vector       errors = this.extractUserDefinedErrors(originalErrors);
 
          StringBuffer results = new StringBuffer();
          results.append(caption);
 
          results.append("<ul>");
 
          for (int i = 0; i < errors.size(); i++) {
             results.append("<li>");
             results.append(MessageResources.getMessage(request,
                                                        (String) errors
                                                        .elementAt(i)));
             results.append("</li>");
          }
 
          results.append("</ul>");
 
          // Print the results to our output writer
          JspWriter writer = pageContext.getOut();
 
          try {
             writer.print(results.toString());
          } catch (IOException e) {
             throw new JspException(e.toString());
          }
       }
 
       // Continue processing this page
       return EVAL_BODY_INCLUDE;
    }
 
 
    /***
     * philip.grunikiewicz 2001-05-10 Iterate through the errors and extract
     * only user-specified text
     *
     * @param errors DOCUMENT ME!
     *
     * @return DOCUMENT ME!
     */
    public Vector extractUserDefinedErrors(Vector errors) {
       Vector newErrors = new Vector();
       String message = null;
       int    index   = 0;
 
       //Get user defined delimiter from messagePrefix attribute
       String delimiter = this.getMessagePrefix();
 
       if (errors != null) {
          Enumeration e = errors.elements();
 
          while (e.hasMoreElements()) {
             message = ((Exception) e.nextElement()).getMessage();
 
             //Check for delimiter
             if ((delimiter != null)
                       && ((index = message.indexOf(delimiter)) != -1)) {
                // Add only what is needed
                message = message.substring(index + delimiter.length());
             }
 
             newErrors.add(message);
          }
       }
 
       return newErrors;
    }
 }