MVC Validation Lower/Higher than other value
You can use a custom validation attribute here is my example with dates. But you can use it with ints too.
First, here is the model :
public DateTime Beggining { get; set; }
[IsDateAfterAttribute("Beggining", true, ErrorMessageResourceType = typeof(LocalizationHelper), ErrorMessageResourceName = "PeriodErrorMessage")]
public DateTime End { get; set; }
And here is the attribute itself :
public sealed class IsDateAfterAttribute : ValidationAttribute, IClientValidatable
{
private readonly string testedPropertyName;
private readonly bool allowEqualDates;
public IsDateAfterAttribute(string testedPropertyName, bool allowEqualDates = false)
{
this.testedPropertyName = testedPropertyName;
this.allowEqualDates = allowEqualDates;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var propertyTestedInfo = validationContext.ObjectType.GetProperty(this.testedPropertyName);
if (propertyTestedInfo == null)
{
return new ValidationResult(string.Format("unknown property {0}", this.testedPropertyName));
}
var propertyTestedValue = propertyTestedInfo.GetValue(validationContext.ObjectInstance, null);
if (value == null || !(value is DateTime))
{
return ValidationResult.Success;
}
if (propertyTestedValue == null || !(propertyTestedValue is DateTime))
{
return ValidationResult.Success;
}
// Compare values
if ((DateTime)value >= (DateTime)propertyTestedValue)
{
if (this.allowEqualDates && value == propertyTestedValue)
{
return ValidationResult.Success;
}
else if ((DateTime)value > (DateTime)propertyTestedValue)
{
return ValidationResult.Success;
}
}
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ErrorMessage = this.ErrorMessageString,
ValidationType = "isdateafter"
};
rule.ValidationParameters["propertytested"] = this.testedPropertyName;
rule.ValidationParameters["allowequaldates"] = this.allowEqualDates;
yield return rule;
}
There is a NuGet package called Foolproof which provides these annotations for you. That said - writing a custom attribute is both pretty easy and good practice.
Using Foolproof would look like:
public class FinanceModel{
public int MinimumCost {get;set;}
[GreaterThan("MinimumCost")]
public int MaximumCost {get;set;}
}