Develop Reference

Custom Validation attribute not working on client side

I have create following custom requiredif attribute and added client side script also validation is working on server side. tag is updated with data-val attributes but client side validation is not triggering. Couldn't figure aout what's I am missing here
public class RequiredIfAttribute : ValidationAttribute, IClientModelValidator//ValidationAttribute
{
private string dependentProperty;
private object targetValue;
public RequiredIfAttribute(string _DependentProperty, object _TargetValue)
{
this.dependentProperty=_DependentProperty ;
this.targetValue=_TargetValue ;
}
public void AddValidation(ClientModelValidationContext context)
{
MergeAttribute(context.Attributes, "data-val-requiredif-dependentproperty", dependentProperty);
MergeAttribute(context.Attributes, "data-val-requiredif-targetvalue","true");
MergeAttribute(context.Attributes, "data-val-requiredif",GetErrorMessage(context));
}
bool MergeAttribute(IDictionary<string, string> attributes, string key, string value)
{
if (attributes.ContainsKey(key))
{
return false;
}
attributes.Add(key, value);
return true;
}
private string GetErrorMessage(ClientModelValidationContext context)
{
return string.Format("{0} is not a valid",
context.ModelMetadata.GetDisplayName());
}
protected override ValidationResult IsValid(object value, System.ComponentModel.DataAnnotations.ValidationContext validationContext)
{
var propertyTestedInfo = validationContext.ObjectType.GetProperty(this.dependentProperty);
if (propertyTestedInfo == null)
{
return new ValidationResult(string.Format("{0} needs to be exist in this object.", this.dependentProperty));
}
var dependendValue = propertyTestedInfo.GetValue(validationContext.ObjectInstance, null);
if (dependendValue == null)
{
return new ValidationResult(string.Format("{0} needs to be populated.", this.dependentProperty));
}
if (!dependendValue.Equals(this.targetValue))
{
var fieldValue = validationContext.ObjectType.GetProperty(validationContext.MemberName).GetValue(validationContext.ObjectInstance, null);
if (fieldValue != null)
{
return ValidationResult.Success;
}
else
{
return new ValidationResult(string.Format("{0} cannot be null", validationContext.MemberName));
}
}
else
{
// Must be ignored
return ValidationResult.Success;
}
}
}
Javascript Code
<script>
$.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
// note - this probably needs to cater for more
// control types, e.g. radios
var control = $(id);
var controltype = control.attr('type');
var actualvalue =
controltype === 'checkbox' ?
control.attr('checked').toString() :
control.val();
// 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;
}
);
$.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;
});
</script>
Generated Tag and class property are as follows
<select data-val-requiredif="ToPositionID is not a valid" data-val-requiredif-dependentproperty="chkToPosReq" data-val-requiredif-targetvalue="true" id="ToPositionID" name="ToPositionID">
Class
public class VMWorkflow
{
[RequiredIf("chkToPosReq", "1")]
public int? ToPositionID { get; set; }
}

Validator.TryValidateProperty throws ArgumentException

I use ListValidation
public class Test
{
[ListValidation(ErrorMessage ="wrong")]
public List<string> Listt { get; set; }
}
ListValidation implementation
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field, AllowMultiple = false)]
public class ListValidationAttribute : ValidationAttribute
{
public override bool IsValid(object value)
{
var list = value as IList;
if (list != null)
{
return list.Count > 0;
}
return false;
}
}
when I test it
Test t = new Test();
List<string> str = new List<string>();
str.Add("haha");
str.Add("hoho");
t.Listt = str;
JsonResult json = ModelValidation.ValidateProperty(t, nameof(t.Listt));
It throws ArgumentException
{System.ArgumentException: The value for property 'Listt' must be of type 'System.Collections.Generic.List`1[System.String]'.
Parameter name: value
at System.ComponentModel.DataAnnotations.Validator.EnsureValidPropertyType(String propertyName, Type propertyType, Object value)
at System.ComponentModel.DataAnnotations.Validator.TryValidateProperty(Object value, ValidationContext validationContext, ICollection`1 validationResults)
at EArchive.Infrastructure.ModelValidation.ValidateProperty(Object obj, String property) in C:\Users\haha\ModelValidation.cs:line 54}
ValidateProperty implementation
public static JsonResult ValidateProperty(object obj, string property)
{
ValidationContext context = new ValidationContext(obj)
{
MemberName = property
};
List<ValidationResult> results = new List<ValidationResult>();
bool valid = Validator.TryValidateProperty(property, context, results);
if (!valid) // there is no error and everything is good
{
return null;
}
string errors = "";
// fetch all errors happened in the property.
foreach (ValidationResult result in results)
{
errors += result.ErrorMessage + "\n <br>";
}
Dictionary<string, string> err = new Dictionary<string, string>()
{
{ "status", "fail" },
{ "message", errors }
};
return new JsonResult(err);
}
What's wrong here?

Validator.TryValidateProperty expects the first argument (object value) to be the value to test for the property rather than the name of it. In your example, you are passing the string Listt instead of the value of t.Listt. In order to get this to work for your purposes, you'll need to change your ValidateProperty function, as follows:
public static JsonResult ValidateProperty(object propertyValue, string propertyName, object sourceObject)
{
ValidationContext context = new ValidationContext(sourceObject)
{
MemberName = propertyName
};
List<ValidationResult> results = new List<ValidationResult>();
bool valid = Validator.TryValidateProperty(propertyValue, context, results);
// ...
Then, just update your call-site accordingly:
JsonResult json = ModelValidation.ValidateProperty(t.Listt, nameof(t.Listt), t);
Here's a blog post I used as inspiration for this answer: https://gigi.nullneuron.net/gigilabs/simple-validation-with-data-annotations/.

How to get property name by one of it's attributes' value using reflection or how to get property info of data property which is currently validating?

I want to write custom validation attribute and add additional member names which have validation errors to validation result. The thing is I want to generate member name dynamically based on property name and invalid match property index or key (I want to validate IEnumerables or IDictionaries) like Names[0], Names[1], Names[key] etc. For example:
Model:
public class ModelClass
{
[ItemMaxLength(10)]
[Display(ResourceType = typeof(CategoriesRename), Name = "CategoryNamesFieldName")]
public IDictionary<string, string> Names { get; set; }
}
Attribute:
public class ItemMaxLengthAttribute : ValidationAttribute
{
private readonly int _maxLength = int.MaxValue;
public ItemMaxLengthAttribute(int maxLength)
{
_maxLength = maxLength;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
...
// I can get instance and it's type from validation context
var instance = validationContext.ObjectInstance; // which is instance of ModelClass
var instanceType = validationContext.ObjectType; //which is typeof(ModelClass)
var dispayName = validationContext.DisplayName; //which is value of Display attribute
...
}
}
So the main idea is (I don't like it ether) get current property been validated by it's DysplayName attribute value (dispayName). I'm kind'a stuck here for a while. Maybe is there some other way to get property info of the property which is validating?
P.S. I've already tried MemberName property, as Alexandre Rondeau suggested, but the problem is that validationContext.MemberName = null so it can't be used. Also MSDN says that this property represents an entity member name, not the name of a corresponding data field and I need the name of a corresponding data field.

Using that code, both test passes, so the MemberName isn't null.
[TestClass]
public class RefectionInValidationTest
{
[TestMethod]
public void GivenAModelWithItemMaxAttributeOnFieldName_WhenValidating_ThenModelClassIsValid()
{
//Arange
var validModelClass = new ModelClass();
var validations = new Collection<ValidationResult>();
//Act
var isValid = Validator.TryValidateObject(validModelClass, new ValidationContext(validModelClass, null, null), validations, true);
//Assert
Assert.IsTrue(isValid);
}
[TestMethod]
public void GivenAModelWithItemMaxAttributeOnFieldNotName_WhenValidating_ThenModelClassIsInvalid()
{
//Arange
var invalidaModelClass = new InvalidModelClass();
var validations = new Collection<ValidationResult>();
//Act
var isValid = Validator.TryValidateObject(invalidaModelClass, new ValidationContext(invalidaModelClass, null, null), validations, true);
//Assert
Assert.IsFalse(isValid);
}
}
public class ModelClass
{
[ItemMaxLength(10)]
public IDictionary<string, string> Names { get; set; }
}
public class InvalidModelClass
{
[ItemMaxLength(10)]
public IDictionary<string, string> NotNames { get; set; }
}
public class ItemMaxLengthAttribute : ValidationAttribute
{
private readonly int _maxLength = int.MaxValue;
public ItemMaxLengthAttribute(int maxLength)
{
_maxLength = maxLength;
}
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var propretyInfo = validationContext.ObjectType.GetProperty(validationContext.MemberName);
if (propretyInfo.Name == "Names")
return ValidationResult.Success;
return new ValidationResult("The property isn't 'Names'");
}
}

You have to use validationContext.MemberName property.
Example:
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var userManager = validationContext.GetService<UserManager<ApplicationUser>>();
var findingTask = userManager.FindByEmailAsync((string)value);
findingTask.Wait();
var user = findingTask.Result;
return user == null
? ValidationResult.Success
: new ValidationResult("This email already in use", new string[] { validationContext.MemberName });
}

not able to get values in client side custom validation function

I am doing client side custom validations using jQuery, I am stuck in getting values from
server side to do operations on client side ....
this is my server side custom validation function
public class SelctedValueCheckAttribute : ValidationAttribute , IClientValidatable
{
public SelctedValueCheckAttribute(string otherProperty): base("{0} is not in correct range")
{
OtherProperty = otherProperty;
}
public string OtherProperty { get; set; }
public SelctedValueCheckAttribute()
{
ErrorMessage = "Values must be in the Given Range";
}
public override string FormatErrorMessage(string name)
{
return "The Entered Value Must be in given range for " + name + "item";
}
protected override ValidationResult IsValid(object firstValue, ValidationContext validationContext)
{
string selecetdItemValue = firstValue as string ;
string userEnteredValue = GetSecondValue(validationContext);
if( string.Equals(selecetdItemValue, "Amount"))
{
int entry = Convert.ToInt32(userEnteredValue);
if (entry < 10 || entry > 20)
{
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
}
else if (string.Equals(selecetdItemValue, "Pound"))
{
int entry = Convert.ToInt32(userEnteredValue);
if (entry < 80 || entry > 90)
{
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
}
else if (string.Equals(selecetdItemValue, "Percent"))
{
int entry = Convert.ToInt32(userEnteredValue);
if (entry < 50 || entry > 60)
{
return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));
}
}
return ValidationResult.Success;
}
protected string GetSecondValue(ValidationContext validationContext)
{
var propertyInfo = validationContext.ObjectType.GetProperty(OtherProperty);
if (propertyInfo != null)
{
var secondValue = propertyInfo.GetValue(validationContext.ObjectInstance, null);
return secondValue as string;
}
return null;
}
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
ModelClientValidationRule mcvr = new ModelClientValidationRule();
mcvr.ValidationType = "enteredvaluescheck";
mcvr.ErrorMessage = "Selected Value must be in given range";
mcvr.ValidationParameters.Add("other", OtherProperty);
mcvr.ValidationType = "selectedvaluewithenteredvaluecheck";
yield return mcvr;
}
}
and this is my client side custom validation
jquery.validator.unobtrusive.adapters.addSingleval("selectedvaluewithenteredvaluecheck", "other");
jQuery.validator.addMethod("selectedvaluewithenteredvaluecheck",
function(val,element,other)
{
if(val & other)
{
// here I am not getting the values..
//do I need to write any function to get the values
//is there any other approach that I need to follow
}
How can I get the values in client side function?
Would any one have any idea about this and any suggestions please suggest me.

You miss-spelled jquery and addSingleval. They should be capitalized Q and V.
jQuery.validator.unobtrusive.adapters.addSingleVal("selectedvaluewithenteredvaluecheck", "other");

Get value of a property that was passed in as a string

I am trying to create a custom validation that says "if the otherValue is true, then this value must be greater than 0. I am able to get the value in, but the way I currently have the otherValue set up, I only have the name of the property, not the value. Probably because it passed in as a string. This attribute is going to be on 5 or 6 different properties and each time, it will be calling a different otherValue. Looking for help on how to get the actual value (it is a bool) of otherValue.
Here is my current code:
public class MustBeGreaterIfTrueAttribute : ValidationAttribute, IClientValidatable
{
// get the radio button value
public string OtherValue { get; set; }
public override bool IsValid(object value)
{
// Here is the actual custom rule
if (value.ToString() == "0")
{
if (OtherValue.ToString() == "true")
{
return false;
}
}
// If all is ok, return successful.
return true;
}
======================EDIT=========================
Here is where I am at now, and it works! Now I need a refernce on how to make it so I can put in a different errorMessage when adding the attribute in the model:
public class MustBeGreaterIfTrueAttribute : ValidationAttribute, IClientValidatable
{
// get the radio button value
public string OtherProperty { get; set; }
protected override ValidationResult IsValid(object value, ValidationContext context)
{
var otherPropertyInfo = context.ObjectInstance.GetType();
var otherValue = otherPropertyInfo.GetProperty(OtherProperty).GetValue(context.ObjectInstance, null);
// Here is the actual custom rule
if (value.ToString() == "0")
{
if (otherValue.ToString().Equals("True", StringComparison.InvariantCultureIgnoreCase))
{
return new ValidationResult("Ensure all 'Yes' answers have additional data entered.");
}
}
// If all is ok, return successful.
return ValidationResult.Success;
}
// Add the client side unobtrusive 'data-val' attributes
public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
{
var rule = new ModelClientValidationRule();
rule.ValidationType = "requiredifyes";
rule.ErrorMessage = this.ErrorMessage;
rule.ValidationParameters.Add("othervalue", this.OtherProperty);
yield return rule;
}
}
So I should be able to do this:
[MustBeGreaterIfTrue(OtherProperty="EverHadRestrainingOrder", ErrorMessage="Enter more info on your RO.")]
public int? ROCounter { get; set; }

The ValidationAttribute has a pair of IsValid methods and for your scenario you have to use other guy.
public class MustBeGreaterIfTrueAttribute : ValidationAttribute
{
// name of the OtherProperty. You have to specify this when you apply this attribute
public string OtherPropertyName { get; set; }
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
var otherProperty = validationContext.ObjectType.GetProperty(OtherPropertyName);
if (otherProperty == null)
return new ValidationResult(String.Format("Unknown property: {0}.", OtherPropertyName));
var otherPropertyValue = otherProperty.GetValue(validationContext.ObjectInstance, null);
if (value.ToString() == "0")
{
if (otherPropertyValue != null && otherPropertyValue.ToString() == "true")
{
return null;
}
}
return new ValidationResult("write something here");
}
}
Example Usage:
public class SomeModel
{
[MustBeGreaterIf(OtherPropertyName="Prop2")]
public string Prop1 {get;set;}
public string Prop2 {get;set;}
}
Ref: http://www.concurrentdevelopment.co.uk/blog/index.php/2011/01/custom-validationattribute-for-comparing-properties/

I'm having a little bit of trouble understanding what you want to do, but,
If you want to get the boolean representation of OtherValue, you could do
bool.Parse(this.OtherValue);
also, for string comparison, it sometimes helps to take case and whitespace out of the picture
if (this.OtherValue.ToString().ToLower().Trim() == "true")

validationContext has ObjectInstance which is an instance of SomeModel class so you can use:
(validationContext.ObjectInstance as SomeModel).Prop1/Prop2