This is a followup question for this one: How does DataAnnotations really work in MVC? There is an example custom validation, and a \"Self Validate Model\" was mentioned. It
Taking the same answer:
After you implement the Self Validate Model, witch is a Server Side Validation, you need to create the Client Side Validation part, for that, just create this 3 steps:
append to your IClientValidateble
class
public IEnumerable<ModelClientValidation> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelCLientValidationRule();
rule.ErrorMessage = FormatErrorMessage(metadata.GetDisplayName());
rule.ValidationType = "greater"; // This is what the jQuery.Validation expects
rule.ValidationParameters.Add("other", OtherPropertyName); // This is the 2nd parameter
yield return rule;
}
Then you need to write the new jQuery Validator and the metadata adapter that will link the jQuery.Validation with your code providing the correct data-
attributes for that field (if of course, UnobtrusiveJavaScriptEnabled
is true)
create a new js
file and attach to your <head>
for example as
<script src="@Url.Content("~/Scripts/customValidation.js")" type="text/javascript"></script>
and append the new validation
jQuery.validator.addMethod("greater", function(value, element, param) {
// we need to take value and compare with the value in 2nd parameter that is hold in param
return Date.parse(value) > Date.parse($(param).val());
});
and then we write the adapter
jQuery.validator.unobtrusive.adapters.add("greater", ["other"], function(options) {
// pass the 'other' property value to the jQuery Validator
options.rules["greater"] = "#" + options.param.other;
// when this rule fails, show message that comes from ErrorMessage
options.messages["greater"] = options.message;
});
You can view this in the AccountModel.cs
when you create a new MVC3 Web Applicatoin, it shows this method that implements the IClientValidatable
[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
public sealed class ValidatePasswordLengthAttribute : ValidationAttribute, IClientValidatable
{
private const string _defaultErrorMessage = "'{0}' must be at least {1} characters long.";
private readonly int _minCharacters = Membership.Provider.MinRequiredPasswordLength;
public ValidatePasswordLengthAttribute()
: base(_defaultErrorMessage)
{
}
public override string FormatErrorMessage(string name)
{
return String.Format(CultureInfo.CurrentCulture, ErrorMessageString,
name, _minCharacters);
}
public override bool IsValid(object value)
{
string valueAsString = value as string;
return (valueAsString != null && valueAsString.Length >= _minCharacters);
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
return new[]{
new ModelClientValidationStringLengthRule(FormatErrorMessage(metadata.GetDisplayName()), _minCharacters, int.MaxValue)
};
}
}
#endregion