Is there a quick way to default the error message for all your fields in a model?
I want the validation to return the text:
" * required "
...but dont want to manually set it on each field.
Thanks Paul
you can write your custom Required Attribute
[AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = true, Inherited = true)]
public sealed class AEMRequiredAttribute: ValidationAttribute
{
private const string _defaultErrorMessage = "* required";
public AEMRequiredAttribute()
: base(_defaultErrorMessage)
{ }
public override string FormatErrorMessage(string name)
{
return String.Format(CultureInfo.CurrentUICulture, "* required", name);
}
public override bool IsValid(object value)
{
if (value == null || String.IsNullOrWhiteSpace(value.ToString())) return false;
else return true;
}
}
call this attribute as below :
public partial class AEMClass
{
[DisplayName("Dis1")]
[AEMRequiredAttribute]
public string ContractNo { get; set; }
}
You could create a new HTML helper and then call into the underlying ValidationMessage or ValidationMessageFor helpers setting the message text as you do so.
Something based on ValidationMessageFor would look like this:
public static class HtmlHelperExtensions {
public static IHtmlString ValidatorMessageWithMyTextFor<TModel, TProperty>(this HtmlHelper<TModel> htmlHelper, Expression<Func<TModel, TProperty>> expression) {
return htmlHelper.ValidationMessageFor<TModel, TProperty>(expression, "required *");
}
}
And you can add that to your view using
#Html.ValidatorMessageWithMyTextFor(m=>m.MyModelPropertyToValidate)
Of course that all works from the view side of the app and not the model side so it all depends where you would like to embed the messages. If it's the model side then AEM's solution is a good one.
Related
I try to create some Html Helpers which will have an opening tag and closing tag which will include other contents like the Html.BeginForm does.
For example in Razor we can use the Html.BeginForm helper which has the following syntax:
#using (Html.BeginForm())
{
}
This code will include the contents of curly brackets within a and . The only way that I solved opening and closing a tag with contents is by using two html helpers. I define two html helpers:
public static MvcHtmlString StartForm(this System.Web.Mvc.HtmlHelper helper)
{
return new MvcHtmlString("<form>");
}
public static MvcHtmlString EndForm(this System.Web.Mvc.HtmlHelper helper)
{
return new MvcHtmlString("</form>");
}
Then I use the helpers using the following example:
#Html.StartForm()
contents
#Html.EndForm()
But I would like to be able to make one html helper which will have the following format in the view:
#using (Html.MyForm())
{
<text>contents</text>
}
Can someone help me with this problem because I do not know even how to search it.
You can define a class just like the way the MvcForm is implemented. The class below allows you to create a tag which contains other elements.
public class MvcTag : IDisposable
{
private string _tag;
private bool _disposed;
private readonly FormContext _originalFormContext;
private readonly ViewContext _viewContext;
private readonly TextWriter _writer;
public MvcTag(ViewContext viewContext, string tag)
{
if (viewContext == null)
{
throw new ArgumentNullException("viewContext");
}
_viewContext = viewContext;
_writer = viewContext.Writer;
_originalFormContext = viewContext.FormContext;
viewContext.FormContext = new FormContext();
_tag = tag;
Begin(); // opening the tag
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
public void Begin()
{
_writer.Write("<" + _tag + ">");
}
private void End()
{
_writer.Write("</" + _tag + ">");
}
protected virtual void Dispose(bool disposing)
{
if (!_disposed)
{
_disposed = true;
End(); // Closing the tag
if (_viewContext != null)
{
_viewContext.OutputClientValidation();
_viewContext.FormContext = _originalFormContext;
}
}
}
public void EndForm()
{
Dispose(true);
}
}
To make use of this MvcTag in the way the MvcForm is used, we have to define an extension
public static class HtmlHelperExtensions
{
public static MvcTag BeginTag(this HtmlHelper htmlHelper, string tag)
{
return new MvcTag(htmlHelper.ViewContext, tag);
}
}
And that's it. Now you can use it as:
#using(Html.BeginTag("div")) #* This creates a <div>, alternatively, you can create any tag with it ("span", "p" etc.) *#
{
<p>Contents</p>
}
I have an MVC app that uses dynamic business objects that are inherited from a parent object type. For example the base class Client might have two sub classes called Vendor and ServiceProvider, and these are all handled by the same controller. I have a partial view that I load on the right side of the page when viewing the client's details called _Aside.cshtml. When I load the client I try to look for a specific Aside first and failing that I load a generic one. Below is what the code looks like.
#try
{
#Html.Partial("_" + Model.Type.TypeName + "Aside")
}
catch (InvalidOperationException ex)
{
#Html.Partial("_Aside")
}
The TypeName property would have the word "Vendor" or "ServiceProvider" in it.
Now this works fine but the problem is I only want it to fail over if the view is not found, It's also failing over when there is an actual InvalidOperationException thrown by the partial view (usually the result of a child action it might call). I've thought about checking against Exception.Message but that seems a bit hackish. Is there some other way I can get the desired result without having to check the Message property or is that my only option at this point?
ex.Message = "The partial view '_ServiceProviderAside' was not found or no view
engine supports the searched locations. The following locations were
searched: (... etc)"
UPDATE: This is the class with extension methods I have currently in my project based off of Jack's answer, and Chao's suggestions as well.
//For ASP.NET MVC
public static class ViewExtensionMethods
{
public static bool PartialExists(this HtmlHelper helper, string viewName)
{
if (string.IsNullOrEmpty(viewName)) throw new ArgumentNullException(viewName, "View name cannot be empty");
var view = ViewEngines.Engines.FindPartialView(helper.ViewContext, viewName);
return view.View != null;
}
public static bool PartialExists(this ControllerContext controllerContext, string viewName)
{
if (string.IsNullOrEmpty(viewName)) throw new ArgumentNullException(viewName, "View name cannot be empty");
var view = ViewEngines.Engines.FindPartialView(controllerContext, viewName);
return view.View != null;
}
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName)
{
return PartialExists(helper, viewName) ? helper.Partial(viewName) : HtmlString.Empty;
}
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName, string fallbackViewName)
{
return OptionalPartial(helper, viewName, fallbackViewName, null);
}
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName, object model)
{
return PartialExists(helper, viewName) ? helper.Partial(viewName, model) : MvcHtmlString.Empty;
}
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName, string fallbackViewName, object model)
{
return helper.Partial(PartialExists(helper, viewName) ? viewName : fallbackViewName, model);
}
public static void RenderOptionalPartial(this HtmlHelper helper, string viewName)
{
if (PartialExists(helper, viewName))
{
helper.RenderPartial(viewName);
}
}
public static void RenderOptionalPartial(this HtmlHelper helper, string viewName, string fallbackViewName)
{
helper.RenderPartial(PartialExists(helper, viewName) ? viewName : fallbackViewName);
}
}
UPDATE: If you happen to be using ASP.NET Core MVC, swap the PartialExists() methods for these three methods, and change all of the usages of HtmlHelper for IHtmlHelper in the other methods. Skip this if you're not using ASP.NET Core
//For ASP.NET Core MVC
public static class ViewExtensionMethods
{
public static bool PartialExists(this IHtmlHelper helper, string viewName)
{
var viewEngine = helper.ViewContext.HttpContext.RequestServices.GetService<ICompositeViewEngine>();
if (string.IsNullOrEmpty(viewName)) throw new ArgumentNullException(viewName, "View name cannot be empty");
var view = viewEngine.FindView(helper.ViewContext, viewName, false);
return view.View != null;
}
public static bool PartialExists(this ControllerContext controllerContext, string viewName)
{
var viewEngine = controllerContext.HttpContext.RequestServices.GetService<ICompositeViewEngine>();
if (string.IsNullOrEmpty(viewName)) throw new ArgumentNullException(viewName, "View name cannot be empty");
var view = viewEngine.FindView(controllerContext, viewName, false);
return view.View != null;
}
public static bool PartialExists(this ViewContext viewContext, string viewName)
{
var viewEngine = viewContext.HttpContext.RequestServices.GetService<ICompositeViewEngine>();
if (string.IsNullOrEmpty(viewName)) throw new ArgumentNullException(viewName, "View name cannot be empty");
var view = viewEngine.FindView(viewContext, viewName, false);
return view.View != null;
}
}
In my view...
#Html.OptionalPartial("_" + Model.Type.TypeName + "Aside", "_Aside")
//or
#Html.OptionalPartial("_" + Model.Type.TypeName + "Aside", "_Aside", Model.AsideViewModel)
Came across this answer while trying to solve the problem of nested sections as I wanted to include styles and scripts in an intermediate view. I ended up deciding the simplest approach was convention of templatename_scripts and templatename_styles.
So just to add to the various options here is what I'm using based on this.
public static class OptionalPartialExtensions
{
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName)
{
return PartialExists(helper, viewName) ? helper.Partial(viewName) : MvcHtmlString.Empty;
}
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName, string fallbackViewName)
{
return helper.Partial(PartialExists(helper, viewName) ? viewName : fallbackViewName);
}
public static void RenderOptionalPartial(this HtmlHelper helper, string viewName)
{
if (PartialExists(helper, viewName))
{
helper.RenderPartial(viewName);
}
}
public static void RenderOptionalPartial(this HtmlHelper helper, string viewName, string fallbackViewName)
{
helper.RenderPartial(PartialExists(helper, viewName) ? viewName : fallbackViewName);
}
public static bool PartialExists(this HtmlHelper helper, string viewName)
{
if (string.IsNullOrEmpty(viewName))
{
throw new ArgumentNullException(viewName, "View name cannot be empty");
}
var view = ViewEngines.Engines.FindPartialView(helper.ViewContext, viewName);
return view.View != null;
}
}
This brings the my most common use cases in to the extension methods helping keep the views that bit cleaner, the RenderPartials were added for completeness.
I had a similar requirement. I wanted to keep the view markup cleaner and also to avoid generating the dynamic view name twice. This is what I came up with (modified to match your example):
Helper extension:
public static string FindPartial(this HtmlHelper html, string typeName)
{
// If you wanted to keep it in the view, you could move this concatenation out:
string viewName = "_" + typeName + "Aside";
ViewEngineResult result = ViewEngines.Engines.FindPartialView(html.ViewContext, viewName);
if (result.View != null)
return viewName;
return "_Aside";
}
View:
#Html.Partial(Html.FindPartial(Model.Type.TypeName))
or with access to the Model within the partial :
#Html.Partial(Html.FindPartial(Model.Type.TypeName), Model)
You could try the FindPartialView method to check if the view exists. Something along these lines might work (untested):
public bool DoesViewExist(string name)
{
string viewName = "_" + Model.Type.TypeName + "Aside";
ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(ControllerContext, viewName , null);
return (viewResult.View != null);
}
Info on the FindPartialView method for ASP MVC 3
Bug fix to handle null viewName or null fallbackViewName (replace appropriate code in OP):
public static MvcHtmlString OptionalPartial(this HtmlHelper helper, string viewName, string fallbackViewName, object model)
{
string partialToRender = null;
if (viewName != null && PartialExists(helper, viewName))
{
partialToRender = viewName;
}
else if (fallbackViewName != null && PartialExists(helper, fallbackViewName))
{
partialToRender = fallbackViewName;
}
if (partialToRender != null)
{
return helper.Partial(partialToRender, model);
}
else
{
return MvcHtmlString.Empty;
}
}
I have edited the OP's code (which combines code from multiple answers), but my edit is pending peer review.
I am setting custom attributes to secure objects within a view. Here is the definition for my custom attributes:
[AttributeUsage(AttributeTargets.Property)]
public class SecureObjectAttribute : Attribute, IMetadataAware
{
public void OnMetadataCreated(ModelMetadata metadata)
{
if(!metadata.AdditionalValues.ContainsKey("isSecure"))
{
if (ObjectId == 1)
{
metadata.AdditionalValues.Add("isSecure", true);
}
else
{
metadata.AdditionalValues.Add("isSecure", false);
}
}
}
public int ObjectId { get; set; }
}
Here is my View Model:
public class HomeViewModel
{
[SecureObject(ObjectId = 1)]
[Display(Name = "Name")]
public string Name { get; set; }
[Display(Name = "Address")]
public string Address { get; set; }
}
I am defining helpers for Secure Labels and Secure TextBoxes. Here are my helper functions:
public static MvcHtmlString SecureLabelFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression)
{
var metadata = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
if ((bool)metadata.AdditionalValues["isSecure"])
{
return null;
}
else
{
return html.LabelFor(expression);
}
}
public static MvcHtmlString SecureTextBoxFor<TModel, TProperty>(this HtmlHelper<TModel> html, Expression<Func<TModel, TProperty>> expression)
{
var metadata = ModelMetadata.FromLambdaExpression(expression, html.ViewData);
if ((bool)metadata.AdditionalValues["isSecure"])
{
return null;
}
else
{
return html.TextBoxFor(expression);
}
}
All of this works correctly, however, the problem that I am having is that every time I define a secure label and a secure textbox, the OnMetadataCreated method is invoked.
I am making a trip to the database on the OnMetadataCreated method (not shown in the example) to get permissions for the object, and I want to avoid duplicate trips for a single object.
The following is an example of code that is causing the OnMetadataCreated to be invoked twice in my View:
#Html.SecureLabelFor(m => m.Name)
#Html.SecureTextBoxFor(m => m.Name)
Any suggestions on how I can avoid a second call to the OnMetadataCreated method, or avoid a duplicate trip to the database?
You could store the result of the execution of the query in the HttpContext to avoid roundtrips to the database within the same request:
public void OnMetadataCreated(ModelMetadata metadata)
{
// TODO: if you are using a DI framework you could pass the context
// as a constructor argument dependency and use HttpContextBase
HttpContext context = HttpContext.Current;
bool isSecure;
string key = "isSecure_" + ObjectId;
if (context.Items.Contains(key))
{
// The isSecure value was found in the HttpContext =>
// no need to query the database once again within this request
isSecure = (bool)context.Items[key];
}
else
{
// Get the value from the database
isSecure = GetFromDb(context.User.Identity.Name, ObjectId);
// and store into the HttpContext to avoid roundtrips to the database
// within this request
context.Items[key] = isSecure;
}
...
}
I have created a custom validation attribute by subclassing ValidationAttribute. The attribute is applied to my viewmodel at the class level as it needs to validate more than one property.
I am overriding
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
and returning:
new ValidationResult("Always Fail", new List<string> { "DateOfBirth" });
in all cases where DateOfBirth is one of the properties on my view model.
When I run my application, I can see this getting hit. ModelState.IsValid is set to false correctly but when I inspect the ModelState contents, I see that the Property DateOfBirth does NOT contain any errors. Instead I have an empty string Key with a value of null and an exception containing the string I specified in my validation attribute.
This results in no error message being displayed in my UI when using ValidationMessageFor. If I use ValidationSummary, then I can see the error. This is because it is not associated with a property.
It looks as though it is ignoring the fact that I have specified the membername in the validation result.
Why is this and how do I fix it?
EXAMPLE CODE AS REQUESTED:
[AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = true)]
public class ExampleValidationAttribute : ValidationAttribute
{
protected override ValidationResult IsValid(object value, ValidationContext validationContext)
{
// note that I will be doing complex validation of multiple properties when complete so this is why it is a class level attribute
return new ValidationResult("Always Fail", new List<string> { "DateOfBirth" });
}
}
[ExampleValidation]
public class ExampleViewModel
{
public string DateOfBirth { get; set; }
}
hello everybody.
Still looking for solution?
I've solved the same problem today. You have to create custom validation attribute which will validate 2 dates (example below). Then you need Adapter (validator) which will validate model with your custom attribute. And the last thing is binding adapter with attribute. Maybe some example will explain it better than me :)
Here we go:
DateCompareAttribute.cs:
[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public class DateCompareAttribute : ValidationAttribute
{
public enum Operations
{
Equals,
LesserThan,
GreaterThan,
LesserOrEquals,
GreaterOrEquals,
NotEquals
};
private string _From;
private string _To;
private PropertyInfo _FromPropertyInfo;
private PropertyInfo _ToPropertyInfo;
private Operations _Operation;
public string MemberName
{
get
{
return _From;
}
}
public DateCompareAttribute(string from, string to, Operations operation)
{
_From = from;
_To = to;
_Operation = operation;
//gets the error message for the operation from resource file
ErrorMessageResourceName = "DateCompare" + operation.ToString();
ErrorMessageResourceType = typeof(ValidationStrings);
}
public override bool IsValid(object value)
{
Type type = value.GetType();
_FromPropertyInfo = type.GetProperty(_From);
_ToPropertyInfo = type.GetProperty(_To);
//gets the values of 2 dates from model (using reflection)
DateTime? from = (DateTime?)_FromPropertyInfo.GetValue(value, null);
DateTime? to = (DateTime?)_ToPropertyInfo.GetValue(value, null);
//compare dates
if ((from != null) && (to != null))
{
int result = from.Value.CompareTo(to.Value);
switch (_Operation)
{
case Operations.LesserThan:
return result == -1;
case Operations.LesserOrEquals:
return result <= 0;
case Operations.Equals:
return result == 0;
case Operations.NotEquals:
return result != 0;
case Operations.GreaterOrEquals:
return result >= 0;
case Operations.GreaterThan:
return result == 1;
}
}
return true;
}
public override string FormatErrorMessage(string name)
{
DisplayNameAttribute aFrom = (DisplayNameAttribute)_FromPropertyInfo.GetCustomAttributes(typeof(DisplayNameAttribute), true).SingleOrDefault();
DisplayNameAttribute aTo = (DisplayNameAttribute)_ToPropertyInfo.GetCustomAttributes(typeof(DisplayNameAttribute), true).SingleOrDefault();
return string.Format(ErrorMessageString,
!string.IsNullOrWhiteSpace(aFrom.DisplayName) ? aFrom.DisplayName : _From,
!string.IsNullOrWhiteSpace(aTo.DisplayName) ? aTo.DisplayName : _To);
}
}
DateCompareAttributeAdapter.cs:
public class DateCompareAttributeAdapter : DataAnnotationsModelValidator<DateCompareAttribute>
{
public DateCompareAttributeAdapter(ModelMetadata metadata, ControllerContext context, DateCompareAttribute attribute)
: base(metadata, context, attribute) {
}
public override IEnumerable<ModelValidationResult> Validate(object container)
{
if (!Attribute.IsValid(Metadata.Model))
{
yield return new ModelValidationResult
{
Message = ErrorMessage,
MemberName = Attribute.MemberName
};
}
}
}
Global.asax:
protected void Application_Start()
{
// ...
DataAnnotationsModelValidatorProvider.RegisterAdapter(typeof(DateCompareAttribute), typeof(DateCompareAttributeAdapter));
}
CustomViewModel.cs:
[DateCompare("StartDateTime", "EndDateTime", DateCompareAttribute.Operations.LesserOrEquals)]
public class CustomViewModel
{
// Properties...
public DateTime? StartDateTime
{
get;
set;
}
public DateTime? EndDateTime
{
get;
set;
}
}
I am not aware of an easy way fix this behavior. That's one of the reasons why I hate data annotations. Doing the same with FluentValidation would be a peace of cake:
public class ExampleViewModelValidator: AbstractValidator<ExampleViewModel>
{
public ExampleViewModelValidator()
{
RuleFor(x => x.EndDate)
.GreaterThan(x => x.StartDate)
.WithMessage("end date must be after start date");
}
}
FluentValidation has great support and integration with ASP.NET MVC.
When returning the validation result use the two parameter constructor.
Pass it an array with the context.MemberName as the only value.
Hope this helps
<AttributeUsage(AttributeTargets.Property Or AttributeTargets.Field, AllowMultiple:=False)>
Public Class NonNegativeAttribute
Inherits ValidationAttribute
Public Sub New()
End Sub
Protected Overrides Function IsValid(num As Object, context As ValidationContext) As ValidationResult
Dim t = num.GetType()
If (t.IsValueType AndAlso Not t.IsAssignableFrom(GetType(String))) Then
If ((num >= 0)) Then
Return ValidationResult.Success
End If
Return New ValidationResult(context.MemberName & " must be a positive number", New String() {context.MemberName})
End If
Throw New ValidationException(t.FullName + " is not a valid type. Must be a number")
End Function
End Class
You need to set the ErrorMessage property, so for example:
public class DOBValidAttribute : ValidationAttribute
{
private static string _errorMessage = "Date of birth is a required field.";
public DOBValidAttribute() : base(_errorMessage)
{
}
//etc......overriding IsValid....
In a model of my ASP.NET MVC application I would like validate a textbox as required only if a specific checkbox is checked.
Something like
public bool retired {get, set};
[RequiredIf("retired",true)]
public string retirementAge {get, set};
How can I do that?
Thank you.
Take a look at this: http://blogs.msdn.com/b/simonince/archive/2010/06/04/conditional-validation-in-mvc.aspx
I've modded the code somewhat to suit my needs. Perhaps you benefit from those changes as well.
public class RequiredIfAttribute : ValidationAttribute
{
private RequiredAttribute innerAttribute = new RequiredAttribute();
public string DependentUpon { get; set; }
public object Value { get; set; }
public RequiredIfAttribute(string dependentUpon, object value)
{
this.DependentUpon = dependentUpon;
this.Value = value;
}
public RequiredIfAttribute(string dependentUpon)
{
this.DependentUpon = dependentUpon;
this.Value = null;
}
public override bool IsValid(object value)
{
return innerAttribute.IsValid(value);
}
}
public class RequiredIfValidator : DataAnnotationsModelValidator<RequiredIfAttribute>
{
public RequiredIfValidator(ModelMetadata metadata, ControllerContext context, RequiredIfAttribute attribute)
: base(metadata, context, attribute)
{ }
public override IEnumerable<ModelClientValidationRule> GetClientValidationRules()
{
// no client validation - I might well blog about this soon!
return base.GetClientValidationRules();
}
public override IEnumerable<ModelValidationResult> Validate(object container)
{
// get a reference to the property this validation depends upon
var field = Metadata.ContainerType.GetProperty(Attribute.DependentUpon);
if (field != null)
{
// get the value of the dependent property
var value = field.GetValue(container, null);
// compare the value against the target value
if ((value != null && Attribute.Value == null) || (value != null && value.Equals(Attribute.Value)))
{
// match => means we should try validating this field
if (!Attribute.IsValid(Metadata.Model))
// validation failed - return an error
yield return new ModelValidationResult { Message = ErrorMessage };
}
}
}
}
Then use it:
public DateTime? DeptDateTime { get; set; }
[RequiredIf("DeptDateTime")]
public string DeptAirline { get; set; }
Just use the Foolproof validation library that is available on Codeplex:
https://foolproof.codeplex.com/
It supports, amongst others, the following "requiredif" validation attributes / decorations:
[RequiredIf]
[RequiredIfNot]
[RequiredIfTrue]
[RequiredIfFalse]
[RequiredIfEmpty]
[RequiredIfNotEmpty]
[RequiredIfRegExMatch]
[RequiredIfNotRegExMatch]
To get started is easy:
Download the package from the provided link
Add a reference to the included .dll file
Import the included javascript files
Ensure that your views references the included javascript files from within its HTML for unobtrusive javascript and jquery validation.
Using NuGet Package Manager I intstalled this: https://github.com/jwaliszko/ExpressiveAnnotations
And this is my Model:
using ExpressiveAnnotations.Attributes;
public bool HasReferenceToNotIncludedFile { get; set; }
[RequiredIf("HasReferenceToNotIncludedFile == true", ErrorMessage = "RelevantAuditOpinionNumbers are required.")]
public string RelevantAuditOpinionNumbers { get; set; }
I guarantee you this will work!
I have not seen anything out of the box that would allow you to do this.
I've created a class for you to use, it's a bit rough and definitely not flexible.. but I think it may solve your current problem. Or at least put you on the right track.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.Globalization;
namespace System.ComponentModel.DataAnnotations
{
[AttributeUsage(AttributeTargets.Class, AllowMultiple = true, Inherited = true)]
public sealed class RequiredIfAttribute : ValidationAttribute
{
private const string _defaultErrorMessage = "'{0}' is required";
private readonly object _typeId = new object();
private string _requiredProperty;
private string _targetProperty;
private bool _targetPropertyCondition;
public RequiredIfAttribute(string requiredProperty, string targetProperty, bool targetPropertyCondition)
: base(_defaultErrorMessage)
{
this._requiredProperty = requiredProperty;
this._targetProperty = targetProperty;
this._targetPropertyCondition = targetPropertyCondition;
}
public override object TypeId
{
get
{
return _typeId;
}
}
public override string FormatErrorMessage(string name)
{
return String.Format(CultureInfo.CurrentUICulture, ErrorMessageString, _requiredProperty, _targetProperty, _targetPropertyCondition);
}
public override bool IsValid(object value)
{
bool result = false;
bool propertyRequired = false; // Flag to check if the required property is required.
PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(value);
string requiredPropertyValue = (string) properties.Find(_requiredProperty, true).GetValue(value);
bool targetPropertyValue = (bool) properties.Find(_targetProperty, true).GetValue(value);
if (targetPropertyValue == _targetPropertyCondition)
{
propertyRequired = true;
}
if (propertyRequired)
{
//check the required property value is not null
if (requiredPropertyValue != null)
{
result = true;
}
}
else
{
//property is not required
result = true;
}
return result;
}
}
}
Above your Model class, you should just need to add:
[RequiredIf("retirementAge", "retired", true)]
public class MyModel
In your View
<%= Html.ValidationSummary() %>
Should show the error message whenever the retired property is true and the required property is empty.
Hope this helps.
Try my custom validation attribute:
[ConditionalRequired("retired==true")]
public string retirementAge {get, set};
It supports multiple conditions.