/*
    * 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.taglib.core;
  
  import javax.el.ELContext;
  import javax.el.ValueExpression;
  import javax.faces.application.Application;
  import javax.faces.context.FacesContext;
  import javax.faces.validator.Validator;
  import javax.faces.webapp.ValidatorELTag;
  import javax.servlet.jsp.JspException;
  
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspAttribute;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspTag;
  
  /**
   * Creates a validator and associates it with the nearest parent UIComponent.
   * <p>
   * During the validation phase (or the apply-request-values phase for immediate components), if the associated component
   * has any submitted value and the conversion of that value to the required type has succeeded then the specified
   * validator type is invoked to test the validity of the converted value.
   * </p>
   * <p>
   * Commonly associated with an h:inputText entity, but may be applied to any input component.
   * </p>
   * <p>
   * Some validators may allow the component to use attributes to define component-specific validation constraints; see
   * the f:attribute tag. See also the "validator" attribute of all input components, which allows a component to specify
   * an arbitrary validation &lt;i&gt;method&lt;/i&gt; (rather than a registered validation type, as this tag does).
   * </p>
   * <p>
   * Unless otherwise specified, all attributes accept static values or EL expressions.
   * </p>
   * 
   * @author Leonardo Uribe (latest modification by $Author$)
   * @version $Revision$ $Date$
   */
  @JSFJspTag(name = "f:validator", bodyContent = "empty")
  public class ValidatorImplTag extends ValidatorELTag
  {
      private ValueExpression _validatorId;
      private ValueExpression _binding;
      private String _validatorIdString = null;
  
      /**
       * The registered ID of the desired Validator.
       */
      @JSFJspAttribute(className="javax.el.ValueExpression",
              deferredValueType="java.lang.String")
      public void setValidatorId(ValueExpression validatorId)
      {
          _validatorId = validatorId;
      }
  
      /**
       * A ValueExpression that evaluates to an implementation of the javax.faces.validator.Validator interface.
       */
      @JSFJspAttribute(className="javax.el.ValueExpression",
              deferredValueType="javax.faces.validator.Validator")
      public void setBinding(ValueExpression binding)
      {
          _binding = binding;
      }
  
      /**
       * Use this method to specify the validatorId programmatically.
       * 
       * @param validatorIdString
       */
      public void setValidatorIdString(String validatorIdString)
      {
          _validatorIdString = validatorIdString;
      }
  
      @Override
      public void release()
      {
          super.release();
          _validatorId = null;
          _binding = null;
          _validatorIdString = null;
      }
  
     @Override
     protected Validator createValidator() throws javax.servlet.jsp.JspException
     {
 
         if (_validatorIdString != null)
         {
             return this.createClassicValidator();
         }
         if (_validatorId != null && _validatorId.isLiteralText())
         {
             return this.createClassicValidator();
         }
 
         return new DelegateValidator(_validatorId, _binding, _validatorIdString);
     }
 
     protected Validator createClassicValidator() throws javax.servlet.jsp.JspException
     {
         FacesContext facesContext = FacesContext.getCurrentInstance();
         ELContext elContext = facesContext.getELContext();
         if (null != _binding)
         {
             Object validator;
             try
             {
                 validator = _binding.getValue(elContext);
             }
             catch (Exception e)
             {
                 throw new JspException("Error while creating the Validator", e);
             }
             if (validator instanceof Validator)
             {
                 return (Validator)validator;
             }
         }
         Application application = facesContext.getApplication();
         Validator validator = null;
         try
         {
             // first check if an ValidatorId was set by a method
             if (null != _validatorIdString)
             {
                 validator = application.createValidator(_validatorIdString);
             }
             else if (null != _validatorId)
             {
                 String validatorId = (String)_validatorId.getValue(elContext);
                 validator = application.createValidator(validatorId);
             }
         }
         catch (Exception e)
         {
             throw new JspException("Error while creating the Validator", e);
         }
 
         if (null != validator)
         {
             if (null != _binding)
             {
                 _binding.setValue(elContext, validator);
             }
             return validator;
         }
         throw new JspException("validatorId and/or binding must be specified");
     }
 
 }