model-view-controller - 比较日期 DataAnnotations Validation asp.net mvc

Question

假设我有一个 StartDate 和一个 EndDate，我不想检查 EndDate 是否与开始日期相差不超过 3 个月

public class DateCompare : ValidationAttribute 
 {
    public String StartDate { get; set; }
    public String EndDate { get; set; }

    //Constructor to take in the property names that are supposed to be checked
    public DateCompare(String startDate, String endDate)
    {
        StartDate = startDate;
        EndDate = endDate;
    }

    public override bool IsValid(object value)
    {
        var str = value.ToString();
        if (string.IsNullOrEmpty(str))
            return true;

        DateTime theEndDate = DateTime.ParseExact(EndDate, "yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture);
        DateTime theStartDate = DateTime.ParseExact(StartDate, "yyyy-MM-dd HH:mm:ss", CultureInfo.InvariantCulture).AddMonths(3);
        return (DateTime.Compare(theStartDate, theEndDate) > 0);
    }
}

我想将其实现到我的验证中

[DateCompare("StartDate", "EndDate", ErrorMessage = "The Deal can only be 3 months long!")]

我知道我在这里遇到错误......但是我如何在 asp.net mvc 中进行这种业务规则验证

Answer 1

这是一个迟到的答案，但我想与其他人分享。这是我如何做到的，以便使用不显眼的客户端验证来验证所有内容:

创建一个属性类:

public class DateCompareValidationAttribute : ValidationAttribute, IClientValidatable
{

  public enum CompareType
  {
      GreatherThen,
      GreatherThenOrEqualTo,
      EqualTo,
      LessThenOrEqualTo,
      LessThen
  }




  private CompareType _compareType;
  private DateTime _fromDate;
  private DateTime _toDate;

  private string _propertyNameToCompare;

  public DateCompareValidationAttribute(CompareType compareType, string message, string compareWith = "")
{
    _compareType = compareType;
    _propertyNameToCompare = compareWith;
    ErrorMessage = message;
}


#region IClientValidatable Members
/// <summary>
/// Generates client validation rules
/// </summary>
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
    ValidateAndGetCompareToProperty(metadata.ContainerType);
    var rule = new ModelClientValidationRule();

    rule.ErrorMessage = ErrorMessage;
    rule.ValidationParameters.Add("comparetodate", _propertyNameToCompare);
    rule.ValidationParameters.Add("comparetype", _compareType);
    rule.ValidationType = "compare";

    yield return rule;
}

#endregion


 protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
     // Have to override IsValid method. If you have any logic for server site validation, put it here. 
    return ValidationResult.Success;

}

/// <summary>
/// verifies that the compare-to property exists and of the right types and returnes this property
/// </summary>
/// <param name="containerType">Type of the container object</param>
/// <returns></returns>
private PropertyInfo ValidateAndGetCompareToProperty(Type containerType)
{
    var compareToProperty = containerType.GetProperty(_propertyNameToCompare);
    if (compareToProperty == null)
    {
        string msg = string.Format("Invalid design time usage of {0}. Property {1} is not found in the {2}", this.GetType().FullName, _propertyNameToCompare, containerType.FullName);
        throw new ArgumentException(msg);
    }
    if (compareToProperty.PropertyType != typeof(DateTime) && compareToProperty.PropertyType != typeof(DateTime?))
    {
        string msg = string.Format("Invalid design time usage of {0}. The type of property {1} of the {2} is not DateType", this.GetType().FullName, _propertyNameToCompare, containerType.FullName);
        throw new ArgumentException(msg);
    }

    return compareToProperty;
}
}

注意:如果要验证时间长度，请向构造函数添加另一个参数并更改此特定类型比较的枚举器

将属性添加到字段中，如下所示:[DateCompareValidation(DateCompareValidationAttribute.CompareType.GreatherThenOrEqualTo, "This Date must be on or after another date", compareWith: "AnotherDate")]

记下您生成的 html 是如何更改的。它应该包括您的验证消息、比较日期的字段名称等。生成的参数将以“data-val-compare”开头。您在 GetClientValidationRules 方法中设置 ValidationType="compare"时定义了此“比较”。

现在您需要匹配的 javascript 代码:添加验证适配器和验证方法。我在这里使用了匿名方法，但您不必这样做。我建议将此代码放在单独的 javascript 文件中，以便此文件与您的属性类一起成为一个控件，可以在任何地方使用。

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

$.validator.addMethod("compare", function (value, element, parameters) {
    // value is the actuall value entered 
    // element is the field itself, that contain the the value (in case the value is not enough)

    var errMsg = "";
    // validate parameters to make sure everyting the usage is right
    if (parameters.comparetodate == undefined) {
        errMsg = "Compare validation cannot be executed: comparetodate parameter not found";
        alert(errMsg);
        return false;
    }
    if (parameters.comparetype == undefined) {
        errMsg = "Compare validation cannot be executed: comparetype parameter not found";
        alert(errMsg);
        return false;
    }


    var compareToDateElement = $('#' + parameters.comparetodate).get();
    if (compareToDateElement.length == 0) {
        errMsg = "Compare validation cannot be executed: Element to compare " + parameters.comparetodate + " not found";
        alert(errMsg);
        return false;
    }
    if (compareToDateElement.length > 1) {
        errMsg = "Compare validation cannot be executed: more then one Element to compare with id " + parameters.comparetodate + " found";
        alert(errMsg);
        return false;
    }
    //debugger;

    if (value && !isNaN(Date.parse(value))) {
        //validate only the value contains a valid date. For invalid dates and blanks non-custom validation should be used    
        //get date to compare
        var compareToDateValue = $('#' + parameters.comparetodate).val();
        if (compareToDateValue && !isNaN(Date.parse(compareToDateValue))) {
            //if date to compare is not a valid date, don't validate this
            switch (parameters.comparetype) {
                case 'GreatherThen':
                    return new Date(value) > new Date(compareToDateValue);
                case 'GreatherThenOrEqualTo':
                    return new Date(value) >= new Date(compareToDateValue);
                case 'EqualTo':
                    return new Date(value) == new Date(compareToDateValue);
                case 'LessThenOrEqualTo':
                    return new Date(value) <= new Date(compareToDateValue);
                case 'LessThen':
                    return new Date(value) < new Date(compareToDateValue);
                default:
                    {
                        errMsg = "Compare validation cannot be executed: '" + parameters.comparetype + "' is invalid for comparetype parameter";
                        alert(errMsg);
                        return false;
                    }
            }
            return true;
        }
        else
            return true;

    }
    else
        return true;
});

这仅负责客户端不显眼的验证。如果您需要服务器端，则必须在 isValid 方法的覆盖中有一些逻辑。此外，您可以使用反射使用显示属性等生成错误消息，并使消息参数可选。