How to fix laravel middleware - laravel

Question

Laravel middle-ware keeps redirecting me to welcome page even if the user is an admin. what i want is if a user is an admin,then he/she can view the routes for the admin, otherwise the user should be redirected to the root page "('/').
I believe i have done everything correctly but somehow i can not view the admin pages, i am redirected to the root page even if a user is an admin.
please assist me fix this bug.
Admin middle-ware class
class Admin
{
/**
* Handle an incoming request.
*
* #param \Illuminate\Http\Request $request
* #param \Closure $next
* #return mixed
*/
public function handle($request, Closure $next)
{
if(Auth::user()->isAdmin()){
return $next($request);
}
return redirect('/');
}
}
User Model
<?php
namespace App;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;
use Illuminate\Notifications\Notifiable;
class User extends Authenticatable
{
use Notifiable;
/**
* The attributes that are mass assignable.
*
* #var array
*/
protected $fillable = [
'name', 'email', 'password', 'role_id','photo_id','gender'
];
/**
* The attributes that should be hidden for arrays.
*
* #var array
*/
protected $hidden = [
'password', 'remember_token',
];
/**
* The attributes that should be cast to native types.
*
* #var array
*/
protected $casts = [
'email_verified_at' => 'datetime',
];
//A role Belongs to a User//
public function role(){
return $this->belongsTo('App\Role');
}
public function photo(){
return $this->belongsTo('App\Photo');
}
public function isAdmin(){
if($this->role->name =='Administrator'){
return true;
}
return false;
}
}
Routes(web.php)
<?php
use Illuminate\Support\Facades\Route;
/*
|--------------------------------------------------------------------------
| Web Routes
|--------------------------------------------------------------------------
|
| Here is where you can register web routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| contains the "web" middleware group. Now create something great!
|
*/
Auth::routes();
Route::group(['middleware'=>'web'],function(){
Route::get('/', function () {
return view('welcome');
});
Route::get('/', [
'uses'=>'HomeController#index',
'as'=>'welcome'
]);
});
Route::group(['middleware'=>['admin']],function(){
Route::resource('/admin/users','AdminUsersController');
Route::get('admin',[
'uses'=>'AdminUsersController#dashboard',
'as'=>'admin.index'
]);
Route::get('admin/users',[
'uses'=>'AdminUsersController#index',
'as'=>'admin.users'
]);
Route::get('admin/users/edit/{id}',[
'as'=>'admin.users.edit',
'uses'=>'AdminUsersController#edit'
]);
Route::get('admin/users/create',[
'as'=>'admin.users.create',
'uses'=>'AdminUsersController#create'
]);
});
Kernel.php
<?php
namespace App\Http;
use Illuminate\Foundation\Http\Kernel as HttpKernel;
class Kernel extends HttpKernel
{
/**
* The application's global HTTP middleware stack.
*
* These middleware are run during every request to your application.
*
* #var array
*/
protected $middleware = [
\App\Http\Middleware\TrustProxies::class,
\Fruitcake\Cors\HandleCors::class,
\App\Http\Middleware\CheckForMaintenanceMode::class,
\Illuminate\Foundation\Http\Middleware\ValidatePostSize::class,
\App\Http\Middleware\TrimStrings::class,
\Illuminate\Foundation\Http\Middleware\ConvertEmptyStringsToNull::class,
];
/**
* The application's route middleware groups.
*
* #var array
*/
protected $middlewareGroups = [
'web' => [
\App\Http\Middleware\EncryptCookies::class,
\Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
\Illuminate\Session\Middleware\StartSession::class,
// \Illuminate\Session\Middleware\AuthenticateSession::class,
\Illuminate\View\Middleware\ShareErrorsFromSession::class,
\App\Http\Middleware\VerifyCsrfToken::class,
\Illuminate\Routing\Middleware\SubstituteBindings::class,
],
'api' => [
'throttle:60,1',
\Illuminate\Routing\Middleware\SubstituteBindings::class,
],
];
/**
* The application's route middleware.
*
* These middleware may be assigned to groups or used individually.
*
* #var array
*/
protected $routeMiddleware = [
'auth' => \App\Http\Middleware\Authenticate::class,
'auth.basic' => \Illuminate\Auth\Middleware\AuthenticateWithBasicAuth::class,
'bindings' => \Illuminate\Routing\Middleware\SubstituteBindings::class,
'cache.headers' => \Illuminate\Http\Middleware\SetCacheHeaders::class,
'can' => \Illuminate\Auth\Middleware\Authorize::class,
'guest' => \App\Http\Middleware\RedirectIfAuthenticated::class,
'password.confirm' => \Illuminate\Auth\Middleware\RequirePassword::class,
'signed' => \Illuminate\Routing\Middleware\ValidateSignature::class,
'throttle' => \Illuminate\Routing\Middleware\ThrottleRequests::class,
'verified' => \Illuminate\Auth\Middleware\EnsureEmailIsVerified::class,
'admin' => \App\Http\Middleware\Admin::class,
];
}