mcs/class/System.ComponentModel.DataAnnotations/System.ComponentModel.DataAnnotations/ValidationAttribute.cs

   1 //
   2 // ValidationAttribute.cs
   3 //
   4 // Authors:
   5 //      Atsushi Enomoto <atsushi@ximian.com>
   6 //      Marek Habersack <mhabersack@novell.com>
   7 //
   8 // Copyright (C) 2008-2010 Novell Inc. http://novell.com
   9 //
  10
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31 using System;
  32 using System.ComponentModel;
  33 using System.Reflection;
  34
  35 namespace System.ComponentModel.DataAnnotations
  36 {
  37         public abstract class ValidationAttribute : Attribute
  38         {
  39                 const string DEFAULT_ERROR_MESSAGE = "The field {0} is invalid.";
  40 #if NET_4_0
  41                 object nestedCallLock = new object ();
  42                 bool nestedCall;
  43 #else
  44                 string errorMessageResourceName;
  45                 string errorMessageString;
  46                 Type errorMessageResourceType;
  47 #endif
  48                 string errorMessage;
  49                 string fallbackErrorMessage;
  50                 Func <string> errorMessageAccessor;
  51
  52                 protected ValidationAttribute ()
  53                 {
  54                 }
  55
  56                 protected ValidationAttribute (Func<string> errorMessageAccessor)
  57                 {
  58                         this.errorMessageAccessor = errorMessageAccessor;
  59                 }
  60
  61                 protected ValidationAttribute (string errorMessage)
  62                 {
  63                         fallbackErrorMessage = errorMessage;
  64                 }
  65
  66                 public virtual string FormatErrorMessage (string name)
  67                 {
  68                         string format = ErrorMessageString;
  69                         if (String.IsNullOrEmpty (format))
  70                                 return String.Empty;
  71
  72                         return String.Format (ErrorMessageString, name);
  73                 }
  74 #if NET_4_0
  75                 public string ErrorMessage {
  76                         get { return errorMessage; }
  77                         set {
  78                                 errorMessage = value;
  79                                 if (errorMessage != null)
  80                                         errorMessageAccessor = null;
  81                         }
  82                 }
  83                 public string ErrorMessageResourceName { get; set; }
  84                 public Type ErrorMessageResourceType { get; set; }
  85 #else
  86                 public string ErrorMessage {
  87                         get { return errorMessage; }
  88
  89                         set {
  90 #if !NET_4_0
  91                                 if (errorMessage != null)
  92                                         throw new InvalidOperationException ("This property can be set only once.");
  93 #endif
  94                                 if (String.IsNullOrEmpty (value))
  95                                         throw new ArgumentException ("Value cannot be null or empty.", "value");
  96
  97                                 if (errorMessageResourceName != null || errorMessageResourceType != null)
  98                                         throw new InvalidOperationException ("This property cannot be set because the attribute is already in the resource mode.");
  99
 100                                 errorMessage = value;
 101                         }
 102                 }
 103
 104                 public string ErrorMessageResourceName {
 105                         get { return errorMessageResourceName; }
 106
 107                         set {
 108                                 if (errorMessageResourceName != null)
 109                                         throw new InvalidOperationException ("This property can be set only once.");
 110
 111                                 if (String.IsNullOrEmpty (value))
 112                                         throw new ArgumentException ("Value cannot be null or empty.", "value");
 113
 114                                 errorMessageResourceName = value;
 115                                 if (errorMessageResourceType != null)
 116                                         errorMessageString = GetStringFromResourceAccessor ();
 117                         }
 118                 }
 119
 120                 public Type ErrorMessageResourceType {
 121                         get { return errorMessageResourceType; }
 122                         set {
 123                                 errorMessageResourceType = value;
 124                                 if (!String.IsNullOrEmpty (errorMessageResourceName))
 125                                         errorMessageString = GetStringFromResourceAccessor ();
 126                         }
 127                 }
 128 #endif
 129                 protected string ErrorMessageString {
 130                         get { return GetStringFromResourceAccessor (); }
 131                 }
 132 #if NET_4_0
 133                 NotImplementedException NestedNIEX ()
 134                 {
 135                         return new NotImplementedException ("IsValid(object value) has not been implemented by this class.  The preferred entry point is GetValidationResult() and classes should override IsValid(object value, ValidationContext context).");
 136                 }
 137
 138                 //
 139                 // This is the weirdest (to be gentle) idea ever... The IsValid (object) overload
 140                 // throws the NIEX when it is called from the default IsValid (object,
 141                 // ValidationContext) overload, but not when directly. And the reverse situation is
 142                 // true as well. That means, the calls detect the "nested" calls and that we need to
 143                 // protect the nestedCall flag... ugh
 144                 //
 145                 public virtual bool IsValid (object value)
 146                 {
 147                         lock (nestedCallLock) {
 148                                 if (nestedCall)
 149                                         throw NestedNIEX ();
 150                                 try {
 151                                         nestedCall = true;
 152                                         return IsValid (value, null) == ValidationResult.Success;
 153                                 } finally {
 154                                         nestedCall = false;
 155                                 }
 156                         }
 157                 }
 158
 159                 protected virtual ValidationResult IsValid (object value, ValidationContext validationContext)
 160                 {
 161                         lock (nestedCallLock) {
 162                                 if (nestedCall)
 163                                         throw NestedNIEX ();
 164
 165                                 try {
 166                                         nestedCall = true;
 167                                         if (!IsValid (value)) {
 168                                                 // .NET emulation
 169                                                 if (validationContext == null)
 170                                                         throw new NullReferenceException (".NET emulation.");
 171                                                 string memberName = validationContext.MemberName;
 172                                                 return new ValidationResult (FormatErrorMessage (validationContext.DisplayName), memberName != null ? new string[] { memberName } : new string[] {});
 173                                         }
 174                                 } finally {
 175                                         nestedCall = false;
 176                                 }
 177                         }
 178
 179                         return ValidationResult.Success;
 180                 }
 181 #else
 182                 public abstract bool IsValid (object value);
 183 #endif
 184
 185 #if NET_4_0
 186                 public ValidationResult GetValidationResult (object value, ValidationContext validationContext)
 187                 {
 188                         if (validationContext == null)
 189                                 throw new ArgumentNullException ("validationContext");
 190
 191                         ValidationResult ret = IsValid (value, validationContext);
 192                         if (ret != null && String.IsNullOrEmpty (ret.ErrorMessage))
 193                                 ret.ErrorMessage = FormatErrorMessage (validationContext.DisplayName);
 194
 195                         return ret;
 196                 }
 197 #endif
 198                 string GetStringFromResourceAccessor ()
 199                 {
 200                         string resourceName = ErrorMessageResourceName;
 201                         Type resourceType = ErrorMessageResourceType;
 202                         string errorMessage = ErrorMessage;
 203
 204                         if (resourceName != null && errorMessage != null)
 205                                 throw new InvalidOperationException ("Either ErrorMessage or ErrorMessageResourceName must be set, but not both.");
 206
 207                         if (resourceType == null ^ resourceName == null)
 208                                 throw new InvalidOperationException ("Both ErrorMessageResourceType and ErrorMessageResourceName must be set on this attribute.");
 209
 210
 211
 212                         if (resourceType != null) {
 213                                 PropertyInfo pi = resourceType.GetProperty (resourceName, BindingFlags.Public | BindingFlags.Static);
 214                                 if (pi == null || !pi.CanRead)
 215                                         throw new InvalidOperationException (
 216                                                 String.Format ("Resource type '{0}' does not have an accessible static property named '{1}'.",
 217                                                                resourceType, resourceName)
 218                                         );
 219
 220                                 if (pi.PropertyType != typeof (string))
 221                                         throw new InvalidOperationException (
 222                                                 String.Format ("The property '{0}' on resource type '{1}' is not a string type.",
 223                                                                resourceName, resourceType)
 224                                         );
 225
 226                                 return pi.GetValue (null, null) as string;
 227                         }
 228
 229                         if (errorMessage == null) {
 230                                 if (errorMessageAccessor != null)
 231                                         return errorMessageAccessor ();
 232
 233                                 if (fallbackErrorMessage != null)
 234                                         return fallbackErrorMessage;
 235                                 else
 236                                         return DEFAULT_ERROR_MESSAGE;
 237                         }
 238
 239                         return errorMessage;
 240                 }
 241 #if NET_4_0
 242                 public void Validate (object value, ValidationContext validationContext)
 243                 {
 244                         if (validationContext == null)
 245                                 throw new ArgumentNullException ("validationContext");
 246
 247                         ValidationResult result = IsValid (value, validationContext);
 248                         if (result != null) {
 249                                 string message = result.ErrorMessage;
 250                                 if (message == null)
 251                                         message = FormatErrorMessage (validationContext.DisplayName);
 252
 253                                 throw new ValidationException (message, this, value);
 254                         }
 255                 }
 256 #endif
 257                 public void Validate (object value, string name)
 258                 {
 259                         if (!IsValid (value))
 260                                 throw new ValidationException (FormatErrorMessage (name), this, value);
 261                 }
 262         }
 263 }