/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
    * with the License.  You may obtain a copy of the License at
    *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.myfaces.renderkit.html;
  
  import java.io.IOException;
  
  import javax.faces.component.UIComponent;
  import javax.faces.component.ValueHolder;
  import javax.faces.component.html.HtmlOutputLabel;
  import javax.faces.context.FacesContext;
  import javax.faces.context.ResponseWriter;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.myfaces.shared_impl.renderkit.JSFAttr;
  import org.apache.myfaces.shared_impl.renderkit.RendererUtils;
  import org.apache.myfaces.shared_impl.renderkit.html.HTML;
  import org.apache.myfaces.shared_impl.renderkit.html.HtmlRenderer;
  import org.apache.myfaces.shared_impl.renderkit.html.HtmlRendererUtils;
  
  
  /**
   * @JSFRenderer
   *   renderKitId="HTML_BASIC"
   *   family="javax.faces.Output"
   *   type="javax.faces.Label"
   *   
   * @author Thomas Spiegl (latest modification by $Author: lu4242 $)
   * @author Anton Koinov
   * @author Martin Marinschek
   * @version $Revision: 659857 $ $Date: 2008-05-24 13:17:47 -0500 (Sat, 24 May 2008) $
   */
  public class HtmlLabelRenderer
  extends HtmlRenderer
  {
      private static final Log log = LogFactory.getLog(HtmlLabelRenderer.class);
  
      public void encodeBegin(FacesContext facesContext, UIComponent uiComponent)
              throws IOException
      {
          super.encodeBegin(facesContext, uiComponent);   //check for NP
  
          ResponseWriter writer = facesContext.getResponseWriter();
  
          encodeBefore(facesContext, writer, uiComponent);
  
          writer.startElement(HTML.LABEL_ELEM, uiComponent);
          HtmlRendererUtils.writeIdIfNecessary(writer, uiComponent, facesContext);
          HtmlRendererUtils.renderHTMLAttributes(writer, uiComponent, HTML.LABEL_PASSTHROUGH_ATTRIBUTES);
  
          String forAttr = getFor(uiComponent);
  
          if (forAttr != null)
          {
            writer.writeAttribute(HTML.FOR_ATTR,
                                  getClientId(facesContext, uiComponent, forAttr), JSFAttr.FOR_ATTR);
          }
          else
          {
              if (log.isWarnEnabled()) {
                  log.warn("Attribute 'for' of label component with id " + uiComponent.getClientId(facesContext)+" is not defined");
              }
          }
  
  
          //MyFaces extension: Render a label text given by value
          //TODO: Move to extended component
          if (uiComponent instanceof ValueHolder)
          {
              String text = RendererUtils.getStringValue(facesContext, uiComponent);
              if(text != null)
              {
                  writer.writeText(text, "value");
              }
          }
  
          writer.flush(); // close start tag
  
          encodeAfterStart(facesContext,writer,uiComponent);
      }
  
      protected void encodeAfterStart(FacesContext facesContext, ResponseWriter writer, UIComponent uiComponent)
          throws IOException
     {
     }
 
     protected void encodeBefore(FacesContext facesContext, ResponseWriter writer, UIComponent uiComponent)
         throws IOException
     {
     }
 
 
     protected String getFor(UIComponent component)
     {
         if (component instanceof HtmlOutputLabel)
         {
             return ((HtmlOutputLabel)component).getFor();
         }
         else
         {
             return (String)component.getAttributes().get(JSFAttr.FOR_ATTR);
         }
     }
 
     protected String getClientId(FacesContext facesContext,
                                  UIComponent uiComponent, String forAttr)
     {
         return RendererUtils.getClientId(facesContext, uiComponent, forAttr);
     }
 
 
     public void encodeEnd(FacesContext facesContext, UIComponent uiComponent)
             throws IOException
     {
         super.encodeEnd(facesContext, uiComponent); //check for NP
 
         ResponseWriter writer = facesContext.getResponseWriter();
 
         encodeBeforeEnd(facesContext, writer, uiComponent);
 
         writer.endElement(HTML.LABEL_ELEM);
 
         encodeAfter(facesContext, writer, uiComponent);
     }
 
     protected void encodeBeforeEnd(FacesContext facesContext, ResponseWriter writer, UIComponent uiComponent)
         throws IOException
     {
     }
 
     protected void encodeAfter(FacesContext facesContext, ResponseWriter writer, UIComponent uiComponent)
         throws IOException
     {
     }
 }