Creating roles in asp.net core

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In this video we will discuss creating roles in asp.net core using the ASP.NET Core Identity API.

RoleManager in ASP.NET Core

• To create a user in asp.net core we use UserManager class. Similarly, to create a role, we use RoleManager class provided by asp.net core
• The built-in IdentityRole class represents a Role
• RoleManager class performs all the CRUD operations i.e Creating, Reading, Updating and Deleting roles from the underlying database table AspNetRoles
• To tell the RoleManager class to work with IdentityRole class, we specify IdentityRole class as the generic argument to RoleManager 
• RoleManager is made available to any controller or view by asp.net core dependency injection system

public class AdministrationController : Controller
{
    private readonly RoleManager<IdentityRole> roleManager;

    public AdministrationController(RoleManager<IdentityRole> roleManager)
    {
        this.roleManager = roleManager;
    }
}

Controller code to create a new role

The code is commented where necessary and is self-explanatory. You get a validation error, if you try to create a role with the same name that already exists.

using EmployeeManagement.ViewModels;

using Microsoft.AspNetCore.Identity;

using Microsoft.AspNetCore.Mvc;

using System.Threading.Tasks;

namespace EmployeeManagement.Controllers

{

    public class AdministrationController : Controller

    {

        private readonly RoleManager<IdentityRole> roleManager;

        public AdministrationController(RoleManager<IdentityRole> roleManager)

        {

            this.roleManager = roleManager;

        }

        [HttpGet]

        public IActionResult CreateRole()

        {

            return View();

        }

        [HttpPost]

        public async Task<IActionResult> CreateRole(CreateRoleViewModel model)

        {

            if (ModelState.IsValid)

            {

                // We just need to specify a unique role name to create a new role

                IdentityRole identityRole = new IdentityRole

                {

                    Name = model.RoleName

                };

                // Saves the role in the underlying AspNetRoles table

                IdentityResult result = await roleManager.CreateAsync(identityRole);

                if (result.Succeeded)

                {

                    return RedirectToAction("index", "home");

                }

                foreach (IdentityError error in result.Errors)

                {

                    ModelState.AddModelError("", error.Description);

                }

            }

            return View(model);

        }

    }

}

Create Role View Model

In ASP.NET core to create a role, all we need is a unique name for the role. We decorated the RoleName property with the [Required] attribute as it is a required field.

using System.ComponentModel.DataAnnotations;

namespace EmployeeManagement.ViewModels

{

    public class CreateRoleViewModel

    {

        [Required]

        [Display(Name = "Role")]

        public string RoleName { get; set; }

    }

}

Create Role View

@model CreateRoleViewModel

@{

    ViewBag.Title = "Create New Role";

}

<form asp-action="CreateRole" method="post" class="mt-3">

    <div asp-validation-summary="All" class="text-danger">

    </div>

    <div class="form-group row">

        <label asp-for="RoleName" class="col-sm-2 col-form-label"></label>

        <div class="col-sm-10">

            <input asp-for="RoleName" class="form-control" placeholder="Name">

            <span asp-validation-for="RoleName" class="text-danger"></span>

        </div>

    </div>

    <div class="form-group row">

        <div class="col-sm-10">

            <button type="submit" class="btn btn-primary" style="width:auto">

                Create Role

            </button>

        </div>

    </div>

</form>