How Bind My Resource file's Key to my properties in ASP.NET Core Razor Page?

Question

I Add a Resource File to my projects and I write a Service :

using Microsoft.Extensions.Localization;
using System.Reflection;
namespace NzShop.Services
{
    public class ComponentsResourceService
    {

        private readonly IStringLocalizer localizer;
        public ComponentsResourceService(IStringLocalizerFactory factory)
        {
            var assemblyName = new AssemblyName(typeof(ComponentsResource).GetTypeInfo().Assembly.FullName!);
            localizer = factory.Create(nameof(ComponentsResource), assemblyName.Name!);
        }

        public string Get(string key)
        {
            return localizer[key];
        }
        public class ComponentsResource { }
    }
}

In Program.cs add:

builder.Services.AddLocalization(options => options.ResourcesPath = "Resources");
builder.Services.Configure<RequestLocalizationOptions>(options =>
{
    var supportedCultures = new[]
     {
        new CultureInfo("en"),
        new CultureInfo("fa"),
        new CultureInfo("tr"),
        new CultureInfo("en-US")
    };
    options.DefaultRequestCulture = new RequestCulture("en");
    options.SupportedCultures = supportedCultures;
    options.SupportedUICultures = supportedCultures;
});

builder.Services.AddMvc().AddViewLocalization()
                    .AddDataAnnotationsLocalization();

builder.Services.AddSingleton<ComponentsResourceService>();

How Can control Required Field from my ComponentsResource.resx file:

[Required(ErrorMessage = ?????)]
public string Familly { get; set; }

score 0 · Answer 1 · answered Apr 16 '23 at 16:10

0

You can directly bind the resource to ErrorMessage.

[Required(ErrorMessage = "{ComponentsResource.FamilyRequired}")]
public string Family { get; set; }

answered Apr 16 '23 at 16:10

AVTUNEY

923
6
11

score 0 · Answer 2 · answered Apr 16 '23 at 23:36

There are multiple ways to set a localized error message for the Required attribute using the .resx file and there are many Stack Overflow and blog posts that cover this topic.

[Required(ErrorMessage = ?????)]

ErrorMessageResourceName/Type validation attributes

A simple, reliable solution that leverages IntelliSense features/validation is to use the combination of the ErrorMessageResourceName and ErrorMessageResourceType validation attributes along with nameof and typeof.

[Required(ErrorMessageResourceName = nameof(ComponentsResource.Required),
    ErrorMessageResourceType = typeof(ComponentsResource))]

ComponentsResource "is the class corresponding to the .resx file where the validation messages are stored".
The nameof expression provides IntelliSense completion for resources defined in the .resx file.
The typeof operator provides validation of the existence of the ComponentsResource class.

Applying the above to your property:

[BindProperty]
[Required(ErrorMessageResourceName = nameof(ComponentsResource.Required),
    ErrorMessageResourceType = typeof(ComponentsResource))]
public string? Familly { get; set; }

These attributes are used in these SO posts here and here but answers does not leverage nameof while this blog post does. These posts suggest, however, a common data annotation localization provider configured through the program.cs file versus the ErrorMessageResourceName/ErrorMessageResourceType validation attributes above.

IValidationMetadataProvider

This Stack Overflow post provides a solution where a localized string format for a validation attribute like [Required] is configured commonly through program.cs.

builder.Services
    .AddMvc(options =>
    {
        options.ModelMetadataDetailsProviders.Add(new LocalizedValidationMetadataProvider());
    })
    .AddDataAnnotationsLocalization();

where the validation metadata provider is defined as:

public class LocalizedValidationMetadataProvider : IValidationMetadataProvider
{
    public LocalizedValidationMetadataProvider()
    {
    }

    public void CreateValidationMetadata(ValidationMetadataProviderContext context)
    {
       ....
    }
}

The SO post provides the full set of steps and code.

How Bind My Resource file's Key to my properties in ASP.NET Core Razor Page?

2 Answers2

ErrorMessageResourceName/Type validation attributes

IValidationMetadataProvider