Where is the whole list of default error messages for DataAnnotations at MVC 3

Question

Yet another MVC localization question...

I'm trying to localize an ASP.Net MVC 3 app using localized Resource files to display texts in the views, as recommended.

The problem is, as usual, when trying to localize the default error messages from data annotations.

I know you can specify the resource file and key in every Attribute:

[Required(
ErrorMessageResourceType = typeof(CustomResourceManager), 
ErrorMessageResourceName = "ResourceKey")]
public string Username { get; set; }

and even, which is better and preferred, you can override the default message, like this: Default resource for data annotations in ASP.NET MVC, so you can leave the Attributes like:

[Required]
public string Username { get; set; }

This last approach is the one I was following, and it works, but only when the DataAnnotation you want to override has ONE and ONLY ONE error message, as it always looks for a resource key called the same as the attribute in the custom resource file (e.g. "Required" needs a "RequiredAttribute" entry in the resource file)

Other attributes, like StringLength, have more than one error message, depending on the optional parameters you use. So, if you have a model like:

public class Person
{
    [Required]
    [StringLengthLocalizedAttribute(10, MinimumLength = 5)]
    [Display(Name = "User name")]
    public string UserName { get; set; }
}

The error message is "The field User name must be a string with a minimum length of 5 and a maximum length of 10."

And if you change the StringLength Attribute to:

    [StringLengthLocalizedAttribute(10)]

the error message changes to "The field User name must be a string with a maximum length of 10." So, in this case, there are at least 2 default error messages to override, and the solutions given by @kim-tranjan fails.

My partial solution to this is implement my own StringLength Attribute like this:

public class StringLengthLocalizedAttribute : StringLengthAttribute
{
    public StringLengthLocalizedAttribute(int maximumLength) : base(maximumLength)
    {
        ErrorMessageResourceType = typeof(CustomValidationResource);
    }

    public override string FormatErrorMessage(string name)
    {
        ErrorMessageResourceName = MinimumLength > 0 ? "StringLengthAttributeMinMax" : "StringLengthAttributeMax";
        return base.FormatErrorMessage(name);
    }
}

Where I have a localized resource "CustomValidationResource" with the validation messages, and set it as the ErrorMessageResourceType. Then, overriding FormatErrorMessage function, I decide which message string should be applied depending on the optional parameters.

So, the question here is: Does anybody know where can we find the whole list of resource keys used by the DataAnnotation Attributes and see then how many different error messages we have in each one without being testing each and every one?

Or even better, can we have the original RESX file to see the string templates and localize them using the same resource keys? This way, changing only the ErrorMessageResourceType should work for all the DataAnnotations Attibutes, and I shouldn't need to guess where to put "{1}" or "{2}" in my localized string.

Thanks, Sergi

Answer 1

In case you were still looking for an overview of the validation strings, below you can find thethe resources from System.ComponentModel.DataAnnotations.Resources.DataAnnotationsResources class as Tz_ mentioned:

[ArgumentIsNullOrWhitespace, The argument '{0}' cannot be null, empty or contain only white space.]
[AssociatedMetadataTypeTypeDescriptor_MetadataTypeContainsUnknownProperties, The associated metadata type for type '{0}' contains the following unknown properties or fields: {1}. Please make sure that the names of these members match the names of the properties on the main type.]
[AttributeStore_Type_Must_Be_Public, The type '{0}' must be public.]
[AttributeStore_Unknown_Method, The type '{0}' does not contain a public method named '{1}'.]
[AttributeStore_Unknown_Property, The type '{0}' does not contain a public property named '{1}'.]
[Common_NullOrEmpty, Value cannot be null or empty.]
[Common_PropertyNotFound, The property {0}.{1} could not be found.]
[CompareAttribute_MustMatch, '{0}' and '{1}' do not match.]
[CompareAttribute_UnknownProperty, Could not find a property named {0}.]
[CreditCardAttribute_Invalid, The {0} field is not a valid credit card number.]
[CustomValidationAttribute_Method_Must_Return_ValidationResult, The CustomValidationAttribute method '{0}' in type '{1}' must return System.ComponentModel.DataAnnotations.ValidationResult.  Use System.ComponentModel.DataAnnotations.ValidationResult.Success to represent success.]
[CustomValidationAttribute_Method_Not_Found, The CustomValidationAttribute method '{0}' does not exist in type '{1}' or is not public and static.]
[CustomValidationAttribute_Method_Required, The CustomValidationAttribute.Method was not specified.]
[CustomValidationAttribute_Method_Signature, The CustomValidationAttribute method '{0}' in type '{1}' must match the expected signature: public static ValidationResult {0}(object value, ValidationContext context).  The value can be strongly typed.  The ValidationContext parameter is optional.]
[CustomValidationAttribute_Type_Conversion_Failed, Could not convert the value of type '{0}' to '{1}' as expected by method {2}.{3}.]
[CustomValidationAttribute_Type_Must_Be_Public, The custom validation type '{0}' must be public.]
[CustomValidationAttribute_ValidationError, {0} is not valid.]
[CustomValidationAttribute_ValidatorType_Required, The CustomValidationAttribute.ValidatorType was not specified.]
[DataTypeAttribute_EmptyDataTypeString, The custom DataType string cannot be null or empty.]
[DisplayAttribute_PropertyNotSet, The {0} property has not been set.  Use the {1} method to get the value.]
[EmailAddressAttribute_Invalid, The {0} field is not a valid e-mail address.]
[EnumDataTypeAttribute_TypeCannotBeNull, The type provided for EnumDataTypeAttribute cannot be null.]
[EnumDataTypeAttribute_TypeNeedsToBeAnEnum, The type '{0}' needs to represent an enumeration type.]
[FileExtensionsAttribute_Invalid, The {0} field only accepts files with the following extensions: {1}]
[LocalizableString_LocalizationFailed, Cannot retrieve property '{0}' because localization failed.  Type '{1}' is not public or does not contain a public static string property with the name '{2}'.]
[MaxLengthAttribute_InvalidMaxLength, MaxLengthAttribute must have a Length value that is greater than zero. Use MaxLength() without parameters to indicate that the string or array can have the maximum allowable length.]
[MaxLengthAttribute_ValidationError, The field {0} must be a string or array type with a maximum length of '{1}'.]
[MetadataTypeAttribute_TypeCannotBeNull, MetadataClassType cannot be null.]
[MinLengthAttribute_InvalidMinLength, MinLengthAttribute must have a Length value that is zero or greater.]
[MinLengthAttribute_ValidationError, The field {0} must be a string or array type with a minimum length of '{1}'.]
[PhoneAttribute_Invalid, The {0} field is not a valid phone number.]
[RangeAttribute_ArbitraryTypeNotIComparable, The type {0} must implement {1}.]
[RangeAttribute_MinGreaterThanMax, The maximum value '{0}' must be greater than or equal to the minimum value '{1}'.]
[RangeAttribute_Must_Set_Min_And_Max, The minimum and maximum values must be set.]
[RangeAttribute_Must_Set_Operand_Type, The OperandType must be set when strings are used for minimum and maximum values.]
[RangeAttribute_ValidationError, The field {0} must be between {1} and {2}.]
[RegexAttribute_ValidationError, The field {0} must match the regular expression '{1}'.]
[RegularExpressionAttribute_Empty_Pattern, The pattern must be set to a valid regular expression.]
[RequiredAttribute_ValidationError, The {0} field is required.]
[StringLengthAttribute_InvalidMaxLength, The maximum length must be a nonnegative integer.]
[StringLengthAttribute_ValidationError, The field {0} must be a string with a maximum length of {1}.]
[StringLengthAttribute_ValidationErrorIncludingMinimum, The field {0} must be a string with a minimum length of {2} and a maximum length of {1}.]
[UIHintImplementation_ControlParameterKeyIsNotAString, The key parameter at position {0} with value '{1}' is not a string. Every key control parameter must be a string.]
[UIHintImplementation_ControlParameterKeyIsNull, The key parameter at position {0} is null. Every key control parameter must be a string.]
[UIHintImplementation_ControlParameterKeyOccursMoreThanOnce, The key parameter at position {0} with value '{1}' occurs more than once.]
[UIHintImplementation_NeedEvenNumberOfControlParameters, The number of control parameters must be even.]
[UrlAttribute_Invalid, The {0} field is not a valid fully-qualified http, https, or ftp URL.]
[ValidationAttribute_Cannot_Set_ErrorMessage_And_Resource, Either ErrorMessageString or ErrorMessageResourceName must be set, but not both.]
[ValidationAttribute_IsValid_NotImplemented, 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).]
[ValidationAttribute_NeedBothResourceTypeAndResourceName, Both ErrorMessageResourceType and ErrorMessageResourceName need to be set on this attribute.]
[ValidationAttribute_ResourcePropertyNotStringType, The property '{0}' on resource type '{1}' is not a string type.]
[ValidationAttribute_ResourceTypeDoesNotHaveProperty, The resource type '{0}' does not have an accessible static property named '{1}'.]
[ValidationAttribute_ValidationError, The field {0} is invalid.]
[ValidationContext_Must_Be_Method, The ValidationContext for the type '{0}', member name '{1}' must provide the MethodInfo.]
[ValidationContextServiceContainer_ItemAlreadyExists, A service of type '{0}' already exists in the container.]
[Validator_InstanceMustMatchValidationContextInstance, The instance provided must match the ObjectInstance on the ValidationContext supplied.]
[Validator_Property_Value_Wrong_Type, The value for property '{0}' must be of type '{1}'.]

(MVC 4, .NET 4.0)

Answer 2

If you open the System.ComponentModel.DataAnnotations.dll with a tool like Reflector you can open the resource System.ComponentModel.DataAnnotations.Resources.DataAnnotationsResources.resources and have a look.

You can also check out the System.ComponentModel.DataAnnotations.Resources.DataAnnotationsResources class that provides access to the resource strings.