Int or Number DataType for DataAnnotation validation attribute

Question

On my MVC3 project, I store score prediction for football/soccer/hockey/... sport game. So one of properties of my prediction class looks like this:

[Range(0, 15, ErrorMessage = "Can only be between 0 .. 15")]
[StringLength(2, ErrorMessage = "Max 2 digits")]
[Remote("PredictionOK", "Predict", ErrorMessage = "Prediction can only be a number in range 0 .. 15")]
public int? HomeTeamPrediction { get; set; }

Now, I need also change error message for a data type, int in my case. There is some default one used - "The field HomeTeamPrediction must be a number.". Need to find a way how to change this error message. This validation message also seem to take prediction for Remote validation one.

I've tried [DataType] attribute but this does not seem to be plain number in system.componentmodel.dataannotations.datatype enumeration.

Answer 1

For any number validation you have to use different different range validation as per your requirements :

For Integer

[Range(0, int.MaxValue, ErrorMessage = "Please enter valid integer Number")]

for float

[Range(0, float.MaxValue, ErrorMessage = "Please enter valid float Number")]

for double

[Range(0, double.MaxValue, ErrorMessage = "Please enter valid doubleNumber")]

Answer 2

Try regular expression

[RegularExpression("([0-9]+)")]      // for 0-inf or 
[RegularExpression("([1-9][0-9]*)"] // for 1-inf

hope it helps :D

Answer 3

Use regex in data annotation

[RegularExpression("([0-9]+)", ErrorMessage = "Please enter valid Number")]
public int MaxJsonLength { get; set; }

Answer 4

Try this attribute :

public class NumericAttribute : ValidationAttribute, IClientValidatable {

    public override bool IsValid(object value) {
        return value.ToString().All(c => (c >= '0' && c <= '9') || c == '-' || c == ' ');
    }


    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context) {
        var rule = new ModelClientValidationRule
        {
            ErrorMessage = FormatErrorMessage(metadata.DisplayName),
            ValidationType = "numeric"
        };
        yield return rule;
    }
}

And also you must register the attribute in the validator plugin:

if($.validator){
     $.validator.unobtrusive.adapters.add(
        'numeric', [], function (options) {
            options.rules['numeric'] = options.params;
            options.messages['numeric'] = options.message;
        }
    );
}

Answer 5

public class IsNumericAttribute : ValidationAttribute
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        if (value != null)
        {
            decimal val;
            var isNumeric = decimal.TryParse(value.ToString(), out val);

            if (!isNumeric)
            {                   
                return new ValidationResult("Must be numeric");                    
            }
        }

        return ValidationResult.Success;
    }
}

Answer 6

almost a decade passed but the issue still valid with Asp.Net Core 2.2 as well.

I managed it by adding data-val-number to the input field the use localization on the message:

<input asp-for="Age" data-val-number="@_localize["Please enter a valid number."]"/>