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 using System.Globalization;
  35
  36 namespace System.ComponentModel.DataAnnotations
  37 {
  38         public abstract class ValidationAttribute : Attribute
  39         {
  40                 const string DEFAULT_ERROR_MESSAGE = "The field {0} is invalid.";
  41 #if NET_4_0
  42                 object nestedCallLock = new object ();
  43                 bool nestedCall;
  44 #else
  45                 string errorMessageResourceName;
  46                 string errorMessageString;
  47                 Type errorMessageResourceType;
  48 #endif
  49                 string errorMessage;
  50                 string fallbackErrorMessage;
  51                 Func <string> errorMessageAccessor;
  52
  53                 protected ValidationAttribute ()
  54                 {
  55                 }
  56
  57                 protected ValidationAttribute (Func<string> errorMessageAccessor)
  58                 {
  59                         this.errorMessageAccessor = errorMessageAccessor;
  60                 }
  61
  62                 protected ValidationAttribute (string errorMessage)
  63                 {
  64                         fallbackErrorMessage = errorMessage;
  65                 }
  66
  67                 public virtual string FormatErrorMessage (string name)
  68                 {
  69                         string format = ErrorMessageString;
  70                         if (String.IsNullOrEmpty (format))
  71                                 return String.Empty;
  72
  73                         return String.Format (ErrorMessageString, name);
  74                 }
  75 #if NET_4_0
  76                 public string ErrorMessage {
  77                         get { return errorMessage; }
  78                         set {
  79                                 errorMessage = value;
  80                                 if (errorMessage != null)
  81                                         errorMessageAccessor = null;
  82                         }
  83                 }
  84                 public string ErrorMessageResourceName { get; set; }
  85                 public Type ErrorMessageResourceType { get; set; }
  86 #else
  87                 public string ErrorMessage {
  88                         get { return errorMessage; }
  89
  90                         set {
  91 #if !NET_4_0
  92                                 if (errorMessage != null)
  93                                         throw new InvalidOperationException ("This property can be set only once.");
  94 #endif
  95                                 if (String.IsNullOrEmpty (value))
  96                                         throw new ArgumentException ("Value cannot be null or empty.", "value");
  97
  98                                 if (errorMessageResourceName != null || errorMessageResourceType != null)
  99                                         throw new InvalidOperationException ("This property cannot be set because the attribute is already in the resource mode.");
 100
 101                                 errorMessage = value;
 102                         }
 103                 }
 104
 105                 public string ErrorMessageResourceName {
 106                         get { return errorMessageResourceName; }
 107
 108                         set {
 109                                 if (errorMessageResourceName != null)
 110                                         throw new InvalidOperationException ("This property can be set only once.");
 111
 112                                 if (String.IsNullOrEmpty (value))
 113                                         throw new ArgumentException ("Value cannot be null or empty.", "value");
 114
 115                                 errorMessageResourceName = value;
 116                                 if (errorMessageResourceType != null)
 117                                         errorMessageString = GetStringFromResourceAccessor ();
 118                         }
 119                 }
 120
 121                 public Type ErrorMessageResourceType {
 122                         get { return errorMessageResourceType; }
 123                         set {
 124                                 errorMessageResourceType = value;
 125                                 if (!String.IsNullOrEmpty (errorMessageResourceName))
 126                                         errorMessageString = GetStringFromResourceAccessor ();
 127                         }
 128                 }
 129 #endif
 130                 protected string ErrorMessageString {
 131                         get { return GetStringFromResourceAccessor (); }
 132                 }
 133
 134 #if NET_4_5
 135                 // See: http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.validationattribute.requiresvalidationcontext.aspx
 136                 public virtual bool RequiresValidationContext { get { return false; } }
 137 #endif
 138
 139 #if NET_4_0
 140                 NotImplementedException NestedNIEX ()
 141                 {
 142                         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).");
 143                 }
 144
 145                 //
 146                 // This is the weirdest (to be gentle) idea ever... The IsValid (object) overload
 147                 // throws the NIEX when it is called from the default IsValid (object,
 148                 // ValidationContext) overload, but not when directly. And the reverse situation is
 149                 // true as well. That means, the calls detect the "nested" calls and that we need to
 150                 // protect the nestedCall flag... ugh
 151                 //
 152                 public virtual bool IsValid (object value)
 153                 {
 154                         lock (nestedCallLock) {
 155                                 if (nestedCall)
 156                                         throw NestedNIEX ();
 157                                 try {
 158                                         nestedCall = true;
 159                                         return IsValid (value, null) == ValidationResult.Success;
 160                                 } finally {
 161                                         nestedCall = false;
 162                                 }
 163                         }
 164                 }
 165
 166                 protected virtual ValidationResult IsValid (object value, ValidationContext validationContext)
 167                 {
 168                         lock (nestedCallLock) {
 169                                 if (nestedCall)
 170                                         throw NestedNIEX ();
 171
 172                                 try {
 173                                         nestedCall = true;
 174                                         if (!IsValid (value)) {
 175                                                 // .NET emulation
 176                                                 if (validationContext == null)
 177                                                         throw new NullReferenceException (".NET emulation.");
 178                                                 string memberName = validationContext.MemberName;
 179                                                 return new ValidationResult (FormatErrorMessage (validationContext.DisplayName), memberName != null ? new string[] { memberName } : new string[] {});
 180                                         }
 181                                 } finally {
 182                                         nestedCall = false;
 183                                 }
 184                         }
 185
 186                         return ValidationResult.Success;
 187                 }
 188 #else
 189                 public abstract bool IsValid (object value);
 190 #endif
 191
 192 #if NET_4_0
 193                 public ValidationResult GetValidationResult (object value, ValidationContext validationContext)
 194                 {
 195                         if (validationContext == null)
 196                                 throw new ArgumentNullException ("validationContext");
 197
 198                         ValidationResult ret = IsValid (value, validationContext);
 199                         if (ret != null && String.IsNullOrEmpty (ret.ErrorMessage))
 200                                 ret.ErrorMessage = FormatErrorMessage (validationContext.DisplayName);
 201
 202                         return ret;
 203                 }
 204 #endif
 205                 string GetStringFromResourceAccessor ()
 206                 {
 207                         string resourceName = ErrorMessageResourceName;
 208                         Type resourceType = ErrorMessageResourceType;
 209                         string errorMessage = ErrorMessage;
 210
 211                         if (resourceName != null && errorMessage != null)
 212                                 throw new InvalidOperationException ("Either ErrorMessage or ErrorMessageResourceName must be set, but not both.");
 213
 214                         if (resourceType == null ^ resourceName == null)
 215                                 throw new InvalidOperationException ("Both ErrorMessageResourceType and ErrorMessageResourceName must be set on this attribute.");
 216
 217
 218
 219                         if (resourceType != null) {
 220                                 PropertyInfo pi = resourceType.GetProperty (resourceName, BindingFlags.Public | BindingFlags.Static);
 221                                 if (pi == null || !pi.CanRead)
 222                                         throw new InvalidOperationException (
 223                                                 String.Format ("Resource type '{0}' does not have an accessible static property named '{1}'.",
 224                                                                resourceType, resourceName)
 225                                         );
 226
 227                                 if (pi.PropertyType != typeof (string))
 228                                         throw new InvalidOperationException (
 229                                                 String.Format ("The property '{0}' on resource type '{1}' is not a string type.",
 230                                                                resourceName, resourceType)
 231                                         );
 232
 233                                 return pi.GetValue (null, null) as string;
 234                         }
 235
 236                         if (errorMessage == null) {
 237                                 if (errorMessageAccessor != null)
 238                                         return errorMessageAccessor ();
 239
 240                                 if (fallbackErrorMessage != null)
 241                                         return fallbackErrorMessage;
 242                                 else
 243                                         return DEFAULT_ERROR_MESSAGE;
 244                         }
 245
 246                         return errorMessage;
 247                 }
 248 #if NET_4_0
 249                 public void Validate (object value, ValidationContext validationContext)
 250                 {
 251                         if (validationContext == null)
 252                                 throw new ArgumentNullException ("validationContext");
 253
 254                         ValidationResult result = IsValid (value, validationContext);
 255                         if (result != null) {
 256                                 string message = result.ErrorMessage;
 257                                 if (message == null)
 258                                         message = FormatErrorMessage (validationContext.DisplayName);
 259
 260                                 throw new ValidationException (message, this, value);
 261                         }
 262                 }
 263 #endif
 264                 public void Validate (object value, string name)
 265                 {
 266                         if (!IsValid (value))
 267                                 throw new ValidationException (FormatErrorMessage (name), this, value);
 268                 }
 269         }
 270 }