Asp.Net MVC验证 - 依赖字段

I'm currently trying to work through MVC validation, and am coming up against some problems where a field is required depending on the value of another field. An example is below (that I haven't figured out yet) - If the PaymentMethod == "Cheque", then the ChequeName should be required, otherwise it can be let through.

我目前正在尝试通过MVC验证，并且遇到了一些需要字段的问题，具体取决于另一个字段的值。下面是一个例子（我还没想到） - 如果PaymentMethod ==“Check”，则需要ChequeName，否则可以通过。

[Required(ErrorMessage = "Payment Method must be selected")]
public override string PaymentMethod
{ get; set; }

[Required(ErrorMessage = "ChequeName is required")]
public override string ChequeName
{ get; set; }

I'm using the System.ComponentModel.DataAnnotations for the [Required], and have also extended a ValidationAttribute to try and get this working, but I can't pass a variable through to do the validation (extension below)

我正在为[Required]使用System.ComponentModel.DataAnnotations，并且还扩展了ValidationAttribute以尝试使其工作，但我无法通过变量来进行验证（下面的扩展名）

public class JEPaymentDetailRequired : ValidationAttribute 
{
    public string PaymentSelected { get; set; }
    public string PaymentType { get; set; }

    public override bool IsValid(object value)
    {
        if (PaymentSelected != PaymentType)
            return true;
        var stringDetail = (string) value;
        if (stringDetail.Length == 0)
            return false;
        return true;
    }
}

Implementation:

执行：

[JEPaymentDetailRequired(PaymentSelected = PaymentMethod, PaymentType = "Cheque", ErrorMessage = "Cheque name must be completed when payment type of cheque")]

Has anyone had experience with this sort of validation? Would it just be better to write it into the controller?

有没有人有这种验证的经验？将它写入控制器会更好吗？

Thanks for your help.

谢谢你的帮助。

4 个解决方案

#1

I would write the validation logic in the model, not the controller. The controller should only handle interaction between the view and the model. Since it's the model that requires validation, I think it's widely regarded as the place for validation logic.

我会在模型中编写验证逻辑，而不是控制器。控制器应该只处理视图和模型之间的交互。由于它是需要验证的模型，我认为它被广泛认为是验证逻辑的地方。

For validation that depends on the value of another property or field, I (unfortunately) don't see how to completely avoid writing some code for that in the model, such as shown in the Wrox ASP.NET MVC book, sort of like:

对于依赖于另一个属性或字段的值的验证，我（遗憾的是）没有看到如何完全避免在模型中为其编写一些代码，如Wrox ASP.NET MVC书中所示，有点像：

public bool IsValid
{
  get 
  {
    SetRuleViolations();
    return (RuleViolations.Count == 0); 
  }
}

public void SetRuleViolations()
{
  if (this.PaymentMethod == "Cheque" && String.IsNullOrEmpty(this.ChequeName))
  {
    RuleViolations.Add("Cheque name is required", "ChequeName");
  }
}

Doing all validation declaratively would be great. I'm sure you could make a RequiredDependentAttribute, but that would only handle this one type of logic. Stuff that is even slightly more complex would require yet another pretty specific attribute, etc. which gets crazy quickly.

以声明方式进行所有验证会很棒。我确信你可以创建一个RequiredDependentAttribute，但那只能处理这种逻辑。甚至稍微复杂一点的东西需要另一个非常具体的属性，等等，它会很快变得疯狂。

#2

If you want client side validation in addition to model validation on the server, I think the best way to go is a custom validation attribute (like Jaroslaw suggested). I'm including the source here of the one I use.

如果除了服务器上的模型验证之外还需要客户端验证，我认为最好的方法是自定义验证属性（如Jaroslaw建议的那样）。我在这里包含了我使用的源码。

Custom attribute:

自定义属性：

public class RequiredIfAttribute : DependentPropertyAttribute
{
    private readonly RequiredAttribute innerAttribute = new RequiredAttribute();

    public object TargetValue { get; set; }


    public RequiredIfAttribute(string dependentProperty, object targetValue) : base(dependentProperty)
    {
        TargetValue = targetValue;
    }


    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        // get a reference to the property this validation depends upon
        var containerType = validationContext.ObjectInstance.GetType();
        var field = containerType.GetProperty(DependentProperty);

        if (field != null)
        {
            // get the value of the dependent property
            var dependentvalue = field.GetValue(validationContext.ObjectInstance, null);

            // compare the value against the target value
            if ((dependentvalue == null && TargetValue == null) ||
                (dependentvalue != null && dependentvalue.Equals(TargetValue)))
            {
                // match => means we should try validating this field
                if (!innerAttribute.IsValid(value))
                    // validation failed - return an error
                    return new ValidationResult(ErrorMessage, new[] { validationContext.MemberName });
            }
        }

        return ValidationResult.Success;
    }

    public override IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule
                       {
                           ErrorMessage = FormatErrorMessage(metadata.GetDisplayName()),
                           ValidationType = "requiredif"
                       };

        var depProp = BuildDependentPropertyId(DependentProperty, metadata, context as ViewContext);

        // find the value on the control we depend on;
        // if it's a bool, format it javascript style 
        // (the default is True or False!)
        var targetValue = (TargetValue ?? "").ToString();
        if (TargetValue != null)
            if (TargetValue is bool)
                targetValue = targetValue.ToLower();

        rule.ValidationParameters.Add("dependentproperty", depProp);
        rule.ValidationParameters.Add("targetvalue", targetValue);

        yield return rule;
    }
}

Jquery validation extension:

Jquery验证扩展：

$.validator.unobtrusive.adapters.add('requiredif', ['dependentproperty', 'targetvalue'], function (options) {
    options.rules['requiredif'] = {
        dependentproperty: options.params['dependentproperty'],
        targetvalue: options.params['targetvalue']
    };
    options.messages['requiredif'] = options.message;
});

$.validator.addMethod('requiredif',
    function (value, element, parameters) {
        var id = '#' + parameters['dependentproperty'];

        // get the target value (as a string, 
        // as that's what actual value will be)
        var targetvalue = parameters['targetvalue'];
        targetvalue = (targetvalue == null ? '' : targetvalue).toString();

        // get the actual value of the target control
        var actualvalue = getControlValue(id);

        // if the condition is true, reuse the existing 
        // required field validator functionality
        if (targetvalue === actualvalue) {
            return $.validator.methods.required.call(this, value, element, parameters);
        }

        return true;
    }
);

Decorating a property with the attribute:

使用属性装饰属性：

[Required]
public bool IsEmailGiftCertificate { get; set; }

[RequiredIf("IsEmailGiftCertificate", true, ErrorMessage = "Please provide Your Email.")]
public string YourEmail { get; set; }

#3

Just use the Foolproof validation library that is available on Codeplex: https://foolproof.codeplex.com/

只需使用Codeplex上提供的Foolproof验证库：https：//foolproof.codeplex.com/

It supports the following "requiredif" validation attributes / decorations:

它支持以下“requiredif”验证属性/装饰：

[RequiredIf]
[RequiredIfNot]
[RequiredIfTrue]
[RequiredIfFalse]
[RequiredIfEmpty]
[RequiredIfNotEmpty]
[RequiredIfRegExMatch]
[RequiredIfNotRegExMatch]

To get started is easy:

开始很容易：

1. Download the package from the provided link
2. 从提供的链接下载包
3. Add a reference to the included .dll file
4. 添加对包含的.dll文件的引用
5. Import the included javascript files
6. 导入包含的javascript文件
7. Ensure that your views references the included javascript files from within its HTML for unobtrusive javascript and jquery validation.
8. 确保您的视图引用其HTML中包含的javascript文件，以进行不引人注目的javascript和jquery验证。

#4

Your problem can be solved relatively simply by the usage of conditional validation attribute e.g.

通过使用条件验证属性，可以相对简单地解决您的问题，例如

[RequiredIf("PaymentMethod == 'Cheque'")]
public string ChequeName { get; set; }