Conditional Data Annotation MVC4

Question

I researched pacas here and did not find a solution for what I wanted. I wonder if anyone has done something similar in MVC4.

Model:

public class Trabalhador
{

    [Required(ErrorMessage = "*")]
    public int Id { get; set; }

    [Required(ErrorMessage = "*")]
    public String Nome { get; set; }

    public String Aposentado { get; set; }

    [Requerido caso o Aposentado seja "S"]
    public DateTime DataAposentadoria { get; set; }
}

View:

@Html.TextBoxFor(model => model.Id)
@Html.ValidationMessageFor(model => model.Id)

@Html.TextBoxFor(model => model.Nome)
@Html.ValidationMessageFor(model => model.Nome)

@Html.TextBoxFor(model => model.Aposentado)
@Html.ValidationMessageFor(model => model.Aposentado)

@Html.TextBoxFor(model => model.DataAposentadoria)
@Html.ValidationMessageFor(model => model.DataAposentadoria)

Here is the X of Questao, I in my form desire all fields, however I want to force me to type the Retirement Date only in the case of a specific value in the Retired attribute (which in case would be "S" or any other value I want). I searched several posts right here in Stack, but none of the models worked.

https://stackoverflow.com/questions/3713281/attribute-dependent-on-another-field/5079585#5079585 http://miroprocessordev.blogspot.com.br/2012/08/aspnet-mvc-conditional-validation-using.html https://stackoverflow.com/questions/2417113/asp-net-mvc-conditional-validation http://blogs.msdn.com/b/simonince/archive/2010/06/04/conditional-validation-in-mvc.aspx

Answer 1

My solution:

[AttributeUsageAttribute(AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Parameter, AllowMultiple = false)]
public class DataAposentadoria : ValidationAttribute
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        var property = validationContext.ObjectInstance.GetType().GetProperty("Aposentado");

        if (property == null)
            return new ValidationResult("Propriedade desconhecida: 'Aposentado'");

        var propertyValue = property.GetValue(validationContext.ObjectInstance, null);

        if (propertyValue != null && propertyValue.ToString() == "S" && value == null)
        {
            return new ValidationResult("Data de aposentadoria deve ser preenchida!");
        }
        return ValidationResult.Success;
    }
}

To use:

public String Aposentado { get; set; }

[DataAposentadoria]
public DateTime? DataAposentadoria { get; set; }

Explaining, when he enters the property, he will try to find out if the "Retired" property exists, if it exists he takes the value and validates.

Of course you can increment to place a dynamic property.

Answer 2

Gentlemen, the Fccdias solution worked, but I had to make a small change, I did not want to change its code, because I could not understand well that block of Javascript, but the only change I made was in the last line: Didn’t Work: Return $(params.item). val() == params.value && value != '&& value.length == 10; Worked: Return "";

Thank you all for your help;

Answer 3

You can implement an attribute that performs a custom validation in the same way as the Required, but only when the condition is satisfied, and use this attribute instead of the Required.

In this attribute implement the interface IClientValidatable to be able to validate in the client, when using nonobstructive validation, and implement a validation implementation with javascript.

An example is in this SOEN response:

• https://stackoverflow.com/a/15975880/195417

I adapted the attribute of the answer presented above to have non-aggressive validation in the client:

public class RequiredIfAttribute : RequiredAttribute, IClientValidatable
{
    private String PropertyName { get; set; }
    private Object Comparand { get; set; }

    public RequiredIfAttribute(String propertyName, Object comparand)
    {
        PropertyName = propertyName;
        Comparand = comparand;
    }

    protected override ValidationResult IsValid(object value, ValidationContext context)
    {
        var instance = context.ObjectInstance;
        var type = instance.GetType();
        var proprtyvalue = type.GetProperty(PropertyName).GetValue(instance, null);

        if (proprtyvalue.ToString() == Comparand.ToString())
        {
            var result = base.IsValid(value, context);
            return result;
        }

        return ValidationResult.Success;
    }

    IEnumerable<ModelClientValidationRule> IClientValidatable.GetClientValidationRules(
        ModelMetadata metadata,
        ControllerContext context)
    {
        var requiredIfRule = new ModelClientValidationRule();
        requiredIfRule.ErrorMessage = this.ErrorMessageString;
        requiredIfRule.ValidationType = "requiredif";
        requiredIfRule.ValidationParameters.Add("propertyname", this.PropertyName);
        requiredIfRule.ValidationParameters.Add("comparand", this.Comparand);
        yield return requiredIfRule;
    }
}

Create a javascript file, and include it on the page with the field to be validated:

$.validator.addMethod("requiredif", function (value, element, params) {
    return $(params.propertyname).val() == params.comparand
        ? value != null && value != "" && value != undefined
        : true;
});

$.validator.unobtrusive.adapters.add(
    "requiredif",
    ["propertyname", "comparand"],
    function (options) {
        options.rules["propertyname"] = "#" + options.params.propertyname;
        options.rules["comparand"] = options.params.comparand;
        options.messages["requiredif"] = options.message;
    });

And wear it like this:

public class Trabalhador
{
    [Required(ErrorMessage = "*")]
    public int Id { get; set; }

    [Required(ErrorMessage = "*")]
    public String Nome { get; set; }

    public String Aposentado { get; set; }

    [RequiredIf("Aposentado", "S")]
    public DateTime DataAposentadoria { get; set; }
}

Reference:

• http://thewayofcode.wordpress.com/tag/custom-unobtrusive-validation/

• http://www.asp.net/mvc/tutorials/hands-on-labs/aspnet-mvc-4-helpers,-Forms-and-validation#Exercise7

I couldn’t determine the authorship of the attribute RequiredIf... searching on Google for RequiredIfAttribute RequiredAttribute returns numerous sources where this code is used. I will search further, and if found, I reference here. If someone finds the author, please feel free to edit the reply, or make a comment.

Answer 4

Create a class that will be the Attribute, with inheritance in the abstract class Validationattribute this being server validation, and implements the interface Iclientvalidatable to create customer validation.

Class: Attribute

public class ValidationIfAposentado : ValidationAttribute, IClientValidatable
{
    public String CompareProperty {get;set;}
    public string CompareValue { get; set; }
    public ValidationIfAposentado(String CompareProperty, String CompareValue)
    {
        this.CompareProperty = CompareProperty;
        this.CompareValue = CompareValue;
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        PropertyInfo propertyInfo = validationContext.ObjectInstance.GetType().GetProperty(CompareProperty);
        if (propertyInfo != null)
        {
            object valor = propertyInfo.GetValue(validationContext.ObjectInstance, null);
            if (!(valor != null && CompareValue.Equals(valor.ToString())))
            {  
               return new ValidationResult(this.ErrorMessage);                   
            }
        }
        return ValidationResult.Success;
    }
    IEnumerable<ModelClientValidationRule> IClientValidatable.GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var erro = new ModelClientValidationRequiredRule(this.ErrorMessage);
        erro.ValidationType = "validationifaposentado";
        erro.ValidationParameters.Add("item", CompareProperty);
        erro.ValidationParameters.Add("value", CompareValue);            
        yield return erro;
    }
}

Class: Laborer

public class Trabalhador
{
    [Required(ErrorMessage = "*")]
    public int Id { get; set; }

    [Required(ErrorMessage = "*")]
    public String Nome { get; set; }

    [MinLength(1), MaxLength(1)]
    public String Aposentado { get; set; }

    [ValidationIfAposentado("Aposentado", "S", ErrorMessage="Como é aposentado digite a data de aposentadoria")]
    [DataType(DataType.Date)]
    public DateTime? DataAposentadoria { get; set; }
}

In class Trabalhador, was made an addition of ? or System.Nullable in the DataAposentadoria, since the same will only have value if the Aposentado be equal "S" if I don’t record the DataAposentadoria as NULL.

With the Attribute Validationifaposentado it will check and validate on the server.

For validation via client (Javascript) this javascript should be implemented right below that is corresponding to server validation.

Javascript: Code using these references from jQuery, jQuery.Validation and jQuery.Unobtrusive.

<script src="/Scripts/jquery-2.1.0.js"></script>
<script src="/Scripts/jquery.validate.js"></script>
<script src="/Scripts/jquery.validate.unobtrusive.js"></script>
<script> 
    jQuery.validator.unobtrusive.adapters.add("validationifaposentado", ["item", "value"],
        function (options) {
            options.rules['validationifaposentado'] = {
                item: "#" + options.params.item,
                value: options.params.value, 
            }
            options.messages["validationifaposentado"] = options.message;                
        });
    jQuery.validator.addMethod("validationifaposentado", function (value, element, params) {            
        if ($(params.item).val() === undefined || $(params.item).val() == '') {
            return true;
        }       
        return $(params.item).val() == params.value && value != '' && value.length == 10;
    });
</script>