2009/05/20 - Apache Shale has been retired.

   /*
    * 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.shale.validator.faces;
  
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.Map;
  import java.util.TreeMap;
  import javax.faces.component.EditableValueHolder;
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.faces.convert.ConverterException;
  import javax.faces.render.Renderer;
  import javax.faces.validator.Validator;
  import org.apache.shale.util.Tags;
  import org.apache.shale.validator.CommonsValidator;
  
  
  /***
   * <p>This renderer is a hybrid renderer decorator that is dynamically
   * registered by the {@link ValidatorRenderKit}
   * for component renderers in the "javax.faces.Input" family.</p>
   */
  public class ValidatorInputRenderer extends Renderer {
  
  
      /***
       * <p>The Renderer that we are wrapping.</p>
       */
      private Renderer defaultRenderer = null;
  
  
      /***
       * <p>This constant is the name of a reserved attribute that will hold
       * a <code>Map</code> of clientId's for the component.</p>
       */
      public static final String VALIDATOR_CLIENTIDS_ATTR = "org.apache.shale.validator.clientIdSet";
  
  
      /***
       * <p>Overloaded constructor is passed the original
       * <code>Renderer</code>.</p>
       *
       * @param defaultRenderer The Renderer we should wrap
       */
      public ValidatorInputRenderer(Renderer defaultRenderer) {
         this.defaultRenderer = defaultRenderer;
      }
  
  
      /*** {@inheritDoc} */
      public String convertClientId(FacesContext context, String id) {
          return defaultRenderer.convertClientId(context, id);
      }
  
  
      /*** {@inheritDoc} */
      public void decode(FacesContext context, UIComponent component) {
          defaultRenderer.decode(context, component);
      }
  
  
      /***
       * <p>This override captures the clientId of the target component before
       * passing on to the original renderer.  The clientId is added to a Map
       * that is used by the {@link org.apache.shale.component.ValidatorScript}
       * component for adding client side JavaScript validation.  This hook is
       * needed when the {@link org.apache.shale.validator.CommonsValidator}
       * is added to a UIData subclass.  The components in this class are not
       * unique per row so the clientId can only be captured during the rendering
       * process.  The Map also contains a snapshot of validator var arguments
       * that contain value binding expressions.  This snapshot of state at
       * renderering is used by the client side JavaScript.  The snapshot
       * allows client side validation in UIData components.</p>
       *
       * @param context FacesContext for the current request
       * @param component UIComponent being rendered
       *
       * @exception IOException if an input/output error occurs
       */
      public void encodeBegin(FacesContext context, UIComponent component) throws IOException {
  
          if (component instanceof EditableValueHolder && component.isRendered()) {
  
                 Tags tagUtils = new Tags();
 
                 EditableValueHolder editableComponent = (EditableValueHolder) component;
 
                 // A map that captures information about a component that might contain
                 // commons validators.  The map is organized by a hierarchy "clientId/validatorType/vars"
                 Map ids = (Map) component.getAttributes().get(VALIDATOR_CLIENTIDS_ATTR);
                 if (ids == null) {
                     ids = new TreeMap();
                     component.getAttributes().put(VALIDATOR_CLIENTIDS_ATTR, ids);
                 }
 
                 // captrue the clientId before renderering
                 String clientId = component.getClientId(context);
                 Map validatorVars = (Map) ids.get(clientId);
                 if (validatorVars == null) {
                     validatorVars = new TreeMap();
                     ids.put(clientId, validatorVars);
                 }
 
 
                 Validator[] validators = editableComponent.getValidators();
                 // look for components using CommonsValidator
                 for (int i = 0; i < validators.length; i++) {
                     if (validators[i] instanceof CommonsValidator) {
                        CommonsValidator validator = (CommonsValidator) validators[i];
 
                        // look for a map of var's by component type
                        Map localVars = (Map) validatorVars.get(validator.getType());
                        if (localVars == null) {
                            localVars = new TreeMap();
                            validatorVars.put(validator.getType(), localVars);
                        } else {
                            localVars.clear();
                        }
 
                        Map vars = validator.getVars();
                        Iterator vi = vars.entrySet().iterator();
                        while (vi.hasNext()) {
                           Map.Entry e = (Map.Entry) vi.next();
                           // only override if the var contains a value binding expression
                           if (e.getValue() != null && e.getValue() instanceof String
                               && isValueReference((String) e.getValue())) {
 
                              localVars.put(e.getKey(), tagUtils.eval((String) e.getValue()));
 
                           }
                        }
 
                     }
                 }
 
         }
 
         defaultRenderer.encodeBegin(context, component);
     }
 
 
     /*** {@inheritDoc} */
     public void encodeChildren(FacesContext context, UIComponent component) throws IOException {
         defaultRenderer.encodeChildren(context, component);
     }
 
 
     /*** {@inheritDoc} */
     public void encodeEnd(FacesContext context, UIComponent component) throws IOException {
         defaultRenderer.encodeEnd(context, component);
     }
 
 
     /*** {@inheritDoc} */
     public Object getConvertedValue(FacesContext context, UIComponent component,
             Object value) throws ConverterException {
         return defaultRenderer.getConvertedValue(context, component, value);
     }
 
 
     /*** {@inheritDoc} */
     public boolean getRendersChildren() {
         return defaultRenderer.getRendersChildren();
     }
 
 
     /***
      * <p>Return true if the specified string contains an EL expression.</p>
      * 
      * <p>This is taken almost verbatim from {@link javax.faces.webapp.UIComponentTag}
      * in order to remove JSP dependencies from the renderers.</p>
      *
      * @param value String to be checked for being an expression
      */
     private boolean isValueReference(String value) {
 
         if (value == null) {
             return false;
         }
 
         int start = value.indexOf("#{");
         if (start < 0) {
             return false;
         }
 
         int end = value.lastIndexOf('}');
         return (end >= 0) && (start < end);
     }
 
 
 }