You could write a custom validation attribute for this purpose:
public class DynamicRangeValidator : ValidationAttribute, IClientValidatable
{
private readonly string _minPropertyName;
private readonly string _maxPropertyName;
public DynamicRangeValidator(string minPropertyName, string maxPropertyName)
{
_minPropertyName = minPropertyName;
_maxPropertyName = maxPropertyName;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var minProperty = validationContext.ObjectType.GetProperty(_minPropertyName);
var maxProperty = validationContext.ObjectType.GetProperty(_maxPropertyName);
if (minProperty == null)
{
return new ValidationResult(string.Format("Unknown property {0}", _minPropertyName));
}
if (maxProperty == null)
{
return new ValidationResult(string.Format("Unknown property {0}", _maxPropertyName));
}
int minValue = (int)minProperty.GetValue(validationContext.ObjectInstance, null);
int maxValue = (int)maxProperty.GetValue(validationContext.ObjectInstance, null);
int currentValue = (int)value;
if (currentValue <= minValue || currentValue >= maxValue)
{
return new ValidationResult(
string.Format(
ErrorMessage,
minValue,
maxValue
)
);
}
return null;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule
{
ValidationType = "dynamicrange",
ErrorMessage = this.ErrorMessage,
};
rule.ValidationParameters["minvalueproperty"] = _minPropertyName;
rule.ValidationParameters["maxvalueproperty"] = _maxPropertyName;
yield return rule;
}
}
and then decorate your view model with it:
public class RangeValidationSampleModel
{
[DynamicRangeValidator("MinValue", "MaxValue", ErrorMessage = "Value must be between {0} and {1}")]
public int Value { get; set; }
public int MinValue { get; set; }
public int MaxValue { get; set; }
}
then you could have a controller serving a view:
public class HomeController : Controller
{
public ActionResult Index()
{
return View(new RangeValidationSampleModel
{
Value = 5,
MinValue = 6,
MaxValue = 8
});
}
[HttpPost]
public ActionResult Index(RangeValidationSampleModel model)
{
return View(model);
}
}
and a view of course:
@model RangeValidationSampleModel
<script src="@Url.Content("~/Scripts/jquery.validate.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.validate.unobtrusive.js")" type="text/javascript"></script>
<script type="text/javascript">
$.validator.unobtrusive.adapters.add('dynamicrange', ['minvalueproperty', 'maxvalueproperty'],
function (options) {
options.rules['dynamicrange'] = options.params;
if (options.message != null) {
$.validator.messages.dynamicrange = options.message;
}
}
);
$.validator.addMethod('dynamicrange', function (value, element, params) {
var minValue = parseInt($('input[name="' + params.minvalueproperty + '"]').val(), 10);
var maxValue = parseInt($('input[name="' + params.maxvalueproperty + '"]').val(), 10);
var currentValue = parseInt(value, 10);
if (isNaN(minValue) || isNaN(maxValue) || isNaN(currentValue) || minValue >= currentValue || currentValue >= maxValue) {
var message = $(element).attr('data-val-dynamicrange');
$.validator.messages.dynamicrange = $.validator.format(message, minValue, maxValue);
return false;
}
return true;
}, '');
</script>
@using (Html.BeginForm())
{
<div>
@Html.LabelFor(x => x.Value)
@Html.EditorFor(x => x.Value)
@Html.ValidationMessageFor(x => x.Value)
</div>
<div>
@Html.LabelFor(x => x.MinValue)
@Html.EditorFor(x => x.MinValue)
</div>
<div>
@Html.LabelFor(x => x.MaxValue)
@Html.EditorFor(x => x.MaxValue)
</div>
<button type="submit">OK</button>
}
Obviously the custom adapter registration should be performed in an external javascript file to avoid polluting the view but for the purpose and conciseness of this post I have put it inside the view.
