Model Binding

• It converts client request data (form values, route data, query string parameters, HTTP headers) into objects that the controller can handle.
• As a result, your controller logic doesn't have to do the work of figuring out the incoming request data; it simply has the data as parameters to its action methods.

public async Task<IActionResult> Login(LoginViewModel model, string returnUrl = null) { ... }

Model Validation

• Validation is supported by decorating your model object with data annotation validation attributes.
• The validation attributes are checked on the client side before values are posted to the server, as well as on the server before the controller action is called.

using System.ComponentModel.DataAnnotations;
public class LoginViewModel
{
    [Required]
    [EmailAddress]
    public string Email { get; set; }

    [Required]
    [DataType(DataType.Password)]
    public string Password { get; set; }

    [Display(Name = "Remember me?")]
    public bool RememberMe { get; set; }
}

public async Task<IActionResult> Login(LoginViewModel model, string returnUrl = null)
{
    if (ModelState.IsValid)
    {
      // work with the model
    }
    // At this point, something failed, redisplay form
    return View(model);
}

• The framework handles validating request data both on the client and on the server.
• Validation logic specified on model types is added to the rendered views as unobtrusive annotations and is enforced in the browser with jQuery Validation.

Filters

• They help developers encapsulate cross-cutting concerns, like exception handling or authorization.
• Filters enable running custom pre- and post-processing logic for action methods, and can be configured to run at certain points within the execution pipeline for a given request.
• Filters can be applied to controllers or actions as attributes (or can be run globally).
• Several filters (such as Authorize) are included in the framework.

Areas

• They provide a way to partition a large ASP.NET Core MVC Web app into smaller functional groupings.
• An area is an MVC structure inside an application.
• In an MVC project, logical components like Model, Controller, and View are kept in different folders, and MVC uses naming conventions to create the relationship between these components.