对自定义属性执行客户端验证

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最佳答案

Here's how to proceed:

Start by defining the custom validation attribute:

public class FutureDateAttribute : ValidationAttribute, IClientValidatable
{
public override bool IsValid(object value)
{
if (value == null || (DateTime)value < DateTime.Now)
return false;


return true;
}


public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
yield return new ModelClientValidationRule
{
ErrorMessage = this.ErrorMessage,
ValidationType = "futuredate"
};
}
}

Notice how it implements IClientValidatable. Next we write our model:

public class MyViewModel
{
[FutureDate(ErrorMessage = "Should be in the future")]
public DateTime Date { get; set; }
}

Then a controller:

public class HomeController : Controller
{
public ActionResult Index()
{
return View(new MyViewModel
{
// intentionally put in the past
Date = DateTime.Now.AddDays(-1)
});
}


[HttpPost]
public ActionResult Index(MyViewModel model)
{
return View(model);
}
}

and finally a view:

@using (Html.BeginForm())
{
@Html.LabelFor(x => x.Date)
@Html.TextBoxFor(x => x.Date)
@Html.ValidationMessageFor(x => x.Date)
<input type="submit" value="OK" />
}

The last part for the magic to happen is to define the custom adapter:

<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">
// we add a custom jquery validation method
jQuery.validator.addMethod('greaterThan', function (value, element, params) {
if (!/Invalid|NaN/.test(new Date(value))) {
return new Date(value) > new Date($(params).val());
}
return isNaN(value) && isNaN($(params).val()) || (parseFloat(value) > parseFloat($(params).val()));
}, '');


// and an unobtrusive adapter
jQuery.validator.unobtrusive.adapters.add('futuredate', { }, function (options) {
options.rules['greaterThan'] = true;
options.messages['greaterThan'] = options.message;
});
</script>