text: #region License
  
  /*
   * Copyright © 2002-2011 the original author or authors.
   *
   * Licensed 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.
   */
  
  #endregion
  
  #region Imports
  
  using System;
  
  using Spring.Expressions;
  using Spring.Util;
  
  #endregion
  
  namespace Spring.Validation
  {
      /// <summary>
      /// Validates that required value is not empty.
      /// </summary>
      /// <remarks>
      /// <p>
      /// This validator uses following rules to determine if target value is valid:
      /// <table>
      ///     <tr>
      ///         <th>Target <see cref="System.Type"/></th>
      ///         <th>Valid Value</th>
      ///     </tr>
      ///     <tr>
      ///         <td>A <see cref="System.String"/>.</td>
      ///         <td>Not <see lang="null"/> or an empty string.</td>
      ///     </tr>
      ///     <tr>
      ///         <td>A <see cref="System.DateTime"/>.</td>
      ///         <td>Not <see cref="System.DateTime.MinValue"/> and not <see cref="System.DateTime.MaxValue"/>.</td>
      ///     </tr>
      ///     <tr>
      ///         <td>One of the number types.</td>
      ///         <td>Not zero.</td>
      ///     </tr>
      ///     <tr>
      ///         <td>A <see cref="System.Char"/>.</td>
      ///         <td>Not <see cref="System.Char.MinValue"/> or whitespace.</td>
      ///     </tr>
      ///     <tr>
      ///         <td>Any reference type other than <see cref="System.String"/>.</td>
      ///         <td>Not <see lang="null"/>.</td>
      ///     </tr>
      /// </table>
      /// </p>
      /// <p>
      /// You cannot use this validator to validate any value types other than the ones
      /// specified in the table above. 
      /// </p>
      /// </remarks>
      /// <author>Aleksandar Seovic</author>
      public class RequiredValidator : BaseSimpleValidator
      {
          #region Constructors
  
          /// <summary>
          /// Creates a new instance of the <see cref="RequiredValidator"/> class.
          /// </summary>
          public RequiredValidator()
          {}
  
          /// <summary>
          /// Creates a new instance of the <see cref="RequiredValidator"/> class.
          /// </summary>
          /// <param name="test">The expression to validate.</param>
          /// <param name="when">The expression that determines if this validator should be evaluated.</param>
          public RequiredValidator(string test, string when) : base(test, when)
          {
              AssertUtils.ArgumentHasText(test, "test");
          }
  
          /// <summary>
          /// Creates a new instance of the <see cref="RequiredValidator"/> class.
          /// </summary>
          /// <param name="test">The expression to validate.</param>
          /// <param name="when">The expression that determines if this validator should be evaluated.</param>
          public RequiredValidator(IExpression test, IExpression when) : base(test, when)
          {
              AssertUtils.ArgumentNotNull(test, "test");
          }
  
          #endregion
  
          /// <summary>
          /// Validates the supplied <paramref name="objectToValidate"/>.
          /// </summary>
          /// <remarks>
          /// In the case of the <see cref="Spring.Validation.RequiredValidator"/> class,
          /// the test should be a variable expression that will be evaluated and the object
          /// obtained as a result of this evaluation will be tested using the rules described
          /// in the class overview of the <see cref="Spring.Validation.RequiredValidator"/>
          /// class.
          /// </remarks>
          /// <param name="objectToValidate">The object to validate.</param>
          /// <returns>
          /// <see lang="true"/> if the supplied <paramref name="objectToValidate"/> is valid.
          /// </returns>
          protected override bool Validate(object objectToValidate)
          {
              if (objectToValidate is String && StringUtils.IsNullOrEmpty((string) objectToValidate))
              {
                  return false;
              }
              else if (objectToValidate is DateTime && (((DateTime) objectToValidate) == DateTime.MinValue || ((DateTime) objectToValidate) == DateTime.MaxValue))
              {
                  return false;
              }
              else if (NumberUtils.IsInteger(objectToValidate) && NumberUtils.IsZero(objectToValidate))
              {
                  return false;
              }
              else if (objectToValidate is Char && (((char) objectToValidate) == Char.MinValue || Char.IsWhiteSpace((char) objectToValidate)))
              {
                  return false;
              }
              else if (NumberUtils.IsDecimal(objectToValidate) && NumberUtils.IsZero(objectToValidate))
              {
                  return false;
              }
              return objectToValidate != null;
          }
      }
  }