How To Properly Integrate Fluent Validation 11 Into An Asp.Net Core Mvc 3 Project? Update Mới

Sure, I’d be happy to provide guidance on how to integrate Fluent Validation 11 into an ASP.Net Core MVC 3 project!

Here are the steps you can follow:

1. Install the FluentValidation.AspNetCore package via NuGet by running the following command in the Package Manager Console:

Install-Package FluentValidation.AspNetCore

1. In your ASP.Net Core MVC 3 project, create a folder named “Validators” and add a new class file for each entity you want to validate. For example, if you have a “Customer” entity, create a “CustomerValidator” class in the “Validators” folder.

2. In the “CustomerValidator” class, inherit from the AbstractValidator<Customer> class and override the Validate method to define your validation rules. For example:

scss
public class CustomerValidator : AbstractValidator<Customer>
{
    public CustomerValidator()
    {
        RuleFor(customer => customer.Name).NotEmpty().WithMessage("Name is required.");
        RuleFor(customer => customer.Email).EmailAddress().WithMessage("Email is not valid.");
        RuleFor(customer => customer.Age).InclusiveBetween(18, 65).WithMessage("Age must be between 18 and 65.");
    }
}

1. In your ASP.Net Core MVC 3 project’s Startup.cs file, add the following code to the ConfigureServices method to register Fluent Validation as a service:

scss
services.AddControllersWithViews().AddFluentValidation();

1. Finally, in each action method of your controller that uses the validated entity as a parameter, add the [Validator(typeof(CustomerValidator))] attribute to enable validation for that entity. For example:

scss
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult Create([Validator(typeof(CustomerValidator))] Customer customer)
{
    if (!ModelState.IsValid)
    {
        return View(customer);
    }

    // Save customer to database

    return RedirectToAction(nameof(Index));
}

That’s it! You have now successfully integrated Fluent Validation 11 into your ASP.Net Core MVC 3 project.

FluentValidation is a popular .NET library that makes it easy to define and validate your application’s input data. Here are the steps to use FluentValidation in .NET Core:

1. Install FluentValidation package: Open the NuGet package manager and install the FluentValidation package.

2. Define a validation class: Create a class that inherits from AbstractValidator<T>, where T is the type you want to validate. In this class, you define the validation rules for the input data.

csharp
public class CustomerValidator : AbstractValidator<Customer>
{
    public CustomerValidator()
    {
        RuleFor(customer => customer.Name).NotEmpty();
        RuleFor(customer => customer.Email).EmailAddress();
    }
}

1. Use the validation class: You can use the validation class in your controller or service. For example, in a controller action, you can create an instance of the validation class and call its Validate method to validate the input data.

csharp
public class CustomersController : ControllerBase
{
    [HttpPost]
    public IActionResult Create(Customer customer)
    {
        var validator = new CustomerValidator();
        var result = validator.Validate(customer);

        if (!result.IsValid)
        {
            return BadRequest(result.Errors);
        }

        // create the customer
        return Ok();
    }
}

1. Add FluentValidation to the dependency injection container: You can register the AbstractValidator<T> and IValidator<T> types in the dependency injection container, so that they can be injected into controllers and services.

csharp
services.AddControllers();
services.AddTransient<IValidator<Customer>, CustomerValidator>();

Now you can inject the IValidator<T> instance into your controller or service constructor and use it to validate input data.

csharp
public class CustomerService
{
    private readonly IValidator<Customer> _customerValidator;

    public CustomerService(IValidator<Customer> customerValidator)
    {
        _customerValidator = customerValidator;
    }

    public void Create(Customer customer)
    {
        var result = _customerValidator.Validate(customer);

        if (!result.IsValid)
        {
            throw new ValidationException(result.Errors);
        }

        // create the customer
    }
}

That’s it! With FluentValidation, you can define complex validation rules for your input data and easily integrate it into your .NET Core application.

Adding validation in ASP.NET Core MVC involves the following steps:

1. Add validation attributes to your model properties: You can add validation attributes such as [Required], [MaxLength], [MinLength], [RegularExpression], etc. to your model properties. These attributes ensure that the user inputs meet the specified criteria.

csharp
public class Employee
{
    public int Id { get; set; }

    [Required(ErrorMessage = "Name is required")]
    [MaxLength(50, ErrorMessage = "Name cannot exceed 50 characters")]
    public string Name { get; set; }

    [Required(ErrorMessage = "Email is required")]
    [EmailAddress(ErrorMessage = "Invalid email address")]
    public string Email { get; set; }

    [Range(18, 60, ErrorMessage = "Age must be between 18 and 60")]
    public int Age { get; set; }
}

1. Use the ModelState object to validate model data: In your controller, you can check the ModelState.IsValid property to determine if the model data is valid.

csharp
[HttpPost]
public IActionResult Create(Employee employee)
{
    if (ModelState.IsValid)
    {
        // Save employee to the database
        return RedirectToAction("Index");
    }
    return View(employee);
}

1. Display validation errors: If the model data is invalid, you can display the validation errors in your view using the ValidationSummary and ValidationMessageFor HTML helpers.

html
@model Employee
<form asp-action="Create" method="post">
    <div class="form-group">
        <label asp-for="Name"></label>
        <input asp-for="Name" class="form-control" />
        <span asp-validation-for="Name" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="Email"></label>
        <input asp-for="Email" class="form-control" />
        <span asp-validation-for="Email" class="text-danger"></span>
    </div>
    <div class="form-group">
        <label asp-for="Age"></label>
        <input asp-for="Age" class="form-control" />
        <span asp-validation-for="Age" class="text-danger"></span>
    </div>
    <button type="submit" class="btn btn-primary">Submit</button>
</form>

1. Configure client-side validation (optional): You can also enable client-side validation by including the necessary JavaScript libraries and adding the following code to your view.

html
@section Scripts {
    <partial name="_ValidationScriptsPartial" />
}

This will add the necessary JavaScript libraries to your page and enable client-side validation.

Adding Fluent Validation in ASP.NET Core 6 is a straightforward process that involves the following steps:

1. Add the FluentValidation.AspNetCore NuGet package to your project.
   You can do this via the NuGet Package Manager or by adding the following line to your project file:

   php
   <PackageReference Include="FluentValidation.AspNetCore" Version="10.3.4" />
   

2. Create a validation class for your model. This class should inherit from AbstractValidator<T> where T is the type of the model you want to validate. For example, if you want to validate a Person model, you would create a class like this:

   csharp
   using FluentValidation;
   
   public class PersonValidator : AbstractValidator<Person>
   {
       public PersonValidator()
       {
           RuleFor(p => p.Name).NotEmpty();
           RuleFor(p => p.Age).GreaterThan(0);
           RuleFor(p => p.Email).EmailAddress();
       }
   }
   

   This class defines validation rules for the Name, Age, and Email properties of the Person model.

3. Register the FluentValidation services in the ASP.NET Core dependency injection container by adding the following code to the ConfigureServices method in your Startup class:

   csharp
   using FluentValidation.AspNetCore;
   
   public void ConfigureServices(IServiceCollection services)
   {
       // other services
       
       services.AddControllers()
           .AddFluentValidation();
   }
   

   This code registers the FluentValidation services and adds them to the pipeline of services that ASP.NET Core will use.

4. In your controller, add the [Validator(typeof(T))] attribute to the action method that receives the model you want to validate. Replace T with the type of your model. For example:

   csharp
   [HttpPost]
   [Validator(typeof(PersonValidator))]
   public IActionResult CreatePerson(Person person)
   {
       if (!ModelState.IsValid)
       {
           return BadRequest(ModelState);
       }
       
       // code to create the person
       
       return Ok();
   }
   

   This code applies the validation rules defined in the PersonValidator class to the person parameter received by the CreatePerson method.

That’s it! You have now added Fluent Validation to your ASP.NET Core 6 project. When the CreatePerson method is called, the PersonValidator will be used to validate the person object, and if any validation errors occur, they will be added to the ModelState object, which can be returned as a BadRequest response.