Laravel: CRUD route has a empty parameter

I’m having a problem with a CRUD route. On my method edit in my controller UserGroupsController, the parameter $userGroup is empty.

UserGroupsController

class UserGroupsController extends Controller
{
    public function edit(UserGroup $userGroup)
      {        
        if (Auth::check())
        {
          $users = User::pluck('name','id')->all();
          $groups = Group::pluck('name','id')->all();
          return view('users-group.edit', compact('userGroup','users','groups'));
        }else{
          return redirect('login');
        }

    }
}

edit.blade.php

<div class="panel panel-default">
 <div class="panel-heading">Edit</div>
     <div class="panel-body">
          {{ $userGroup }}
          {!! Form::model($userGroup,['method' => 'PATCH', 'route' => ['users-group.update', $userGroup->id], 'id' => 'user_group-form', 'class' => 'form-horizontal'] ) !!}
          {{ csrf_field() }}

          <input type='hidden' name='id' value='{!! $userGroup->id !!}'>
          @include('users-group.form',array('submitButton' => 'Edit User Group'))              
       {!! Form::close()  !!}
</div>

form.blade.php

<div class="form-group">
  <label for="user_id" class="col-md-4 control-label">User</label>
  <div class="col-md-6">
    {!! form::select('user_id', $users, $userGroup->user_id,['class' => 'form-control']) !!}
  </div>
</div>
<div class="form-group">
  <label for="group_id" class="col-md-4 control-label">Group</label>
  <div class="col-md-6">
    {!! form::select('group_id', $groups, $userGroup->group_id,['class' => 'form-control']) !!}
  </div>
</div>
<div class="form-group">
    <div class="col-md-6 col-md-offset-4">
        {!! Form::submit($submitButton) !!}
    </div>
</div>

Routes:

Route::group(['middleware'=>['web']], function ()
{
  Route::resource('users','UsersController');
  Route::resource('users-group','UserGroupsController');
  Route::resource('companies','CompaniesController');
});

php artisan route:list :

|        | POST      | users-group                    | users-group.store   | AppHttpControllersUserGroupsController@store                        | web          |
|        | GET|HEAD  | users-group/create             | users-group.create  | AppHttpControllersUserGroupsController@create                       | web          |
|        | PUT|PATCH | users-group/{users_group}      | users-group.update  | AppHttpControllersUserGroupsController@update                       | web          |
|        | DELETE    | users-group/{users_group}      | users-group.destroy | AppHttpControllersUserGroupsController@destroy                      | web          |
|        | GET|HEAD  | users-group/{users_group}      | users-group.show    | AppHttpControllersUserGroupsController@show                         | web          |
|        | GET|HEAD  | users-group/{users_group}/edit | users-group.edit    | AppHttpControllersUserGroupsController@edit

dd($userGroup):

UserGroup {#199 ▼
  #fillable: array:2 [▼
    0 => "user_id"
    1 => "group_id"
  ]
  #connection: null
  #table: null
  #primaryKey: "id"
  #keyType: "int"
  #perPage: 15
  +incrementing: true
  +timestamps: true
  #attributes: []
  #original: []
  #relations: []
  #hidden: []
  #visible: []
  #appends: []
  #guarded: array:1 [▶]
  #dates: []
  #dateFormat: null
  #casts: []
  #touches: []
  #observables: []
  #with: []
  +exists: false
  +wasRecentlyCreated: false
}

In the file edit.blade.php, I print the variable $userGroup, but returns “[ ]”. And I have the same code to UsersControllers, but there works.

When I submit the form, I got this error:

MethodNotAllowedHttpException in RouteCollection.php

Sorry for the english, I hope that you understand my problem and I can give more information. thanks

Answer

An edit method usually gets an id. To fix your problem, remove the type from the header and get the model in your method:

class UserGroupsController extends Controller
{
    public function edit($id)
      {        
        $userGroup = UserGroup::findOrFail($id);
        if (Auth::check())
        {
          $users = User::pluck('name','id')->all();
          $groups = Group::pluck('name','id')->all();
          return view('users-group.edit', compact('userGroup','users','groups'));
        }else{
          return redirect('login');
        }

    }
}