Range Validator

Class Name: RangeValidator<T>

Attribute Name: RangeValidatorAttribute

Configuration tool name: Range Validator

Description

This validator checks that a value falls in a specified range. The range may be either closed, which means it has both a lower and an upper bound specified, or open, which means that it only has one bound****specified.

The Range Validator can be used with any type that implements the IComparable interface. This includes all numeric types and strings. While it is possible, in code, to use this validator with DateTime types, the Date Time Range Validator may be a better choice because it allows you to take advantage of attributes and configuration.

Properties

The following table lists the Range Validator<T> properties.

Range Validator<T> Properties

Property

Description

LowerBound

This is the low-range boundary value. It can be any IComparable type that is compatible with the target. The compiler checks this requirement if you directly invoke the validator in your code. If you use attributes or configuration, the application block attempts to convert the supplied string representation of the value to the correct type at run time.

LowerBoundType

This property determines how to evaluate the LowerBound value. Possible values for LowerBoundType are Ignore, Inclusive, and Exclusive. The Ignore value means that the validator ignores the LowerBound value. This is the default. The Inclusive value means that the validator allows values that are equal to the LowerBound value. The Exclusive value means that the validator does not allow values that are equal to the LowerBound value.

Negated

This is a Boolean property. If it is set to True, it changes the validator's behavior so that it will fail if the condition is met, rather than when it is not met. The default is False.

Tag

This property is a user-supplied string. Typically, it is used to sort or categorize validation results that are in a log.

UpperBound

This is the upper-range boundary value. It can be any IComparable type that is compatible with the target. The compiler checks this requirement if you directly invoke the validator in your code. If you use attributes or configuration, the application block attempts to convert the supplied string representation of the value to the correct type at run time..

UpperBoundType

This property determines how to evaluate the UpperBound value. Possible values for LowerBoundType are Ignore, Inclusive, and Exclusive. The Ignore value means that the validator ignores the UpperBound value. This is the default. The Inclusive value means that the validator allows values that are equal to the UpperBound value. The Exclusive value means that the validator does not allow values that are equal to the UpperBound value.

MessageTemplate

This property is a user-supplied string. Typically, it describes the validation result and is intended for a log.

MessageTemplateResourceName

If you do not want to use the MessageTemplate property to specify a message, you can use another template by specifying it with the MessageTemplateResourceName value. If you include both a MessageTemplate value and a MessageResourceName value, the MessageTemplate value takes precedence.

MessageTemplateResourceTypeName

If you specify a MessageTemplateResourceName value then you must specify a MessageTemplateResourceTypeName value, which is the type of the template you want to use.

Message Template Tokens

If the message template contains tokens (for instance, "{0}"), the validator will replace these tokens with values when the ValidationResult is created. The tokens supported by the RangeValidator are as follows:

Examples

The following examples show how to use the validator with attributes and with code.

Attributes

The following code example checks that the Age property is between 0 and 110, inclusive.

public class Person
{
   [RangeValidator(0, RangeBoundaryType.Inclusive, 
110, RangeBoundaryType.Inclusive)]
   int Age
   {
      get
      {
         return this.CalculateAge();
      }
   )
   // ...
}

'Usage
Public Class Person
    <RangeValidator(0, RangeBoundaryType.Inclusive, 110, _
RangeBoundaryType.Inclusive)> _
    ReadOnly Property Age() As Integer
        Get
            Return Me.CalculateAge()
        End Get
    End Property
    ' ...
End Class