Append errors with custom error - laravel

Question

How can i append the $errors->all() array? Like a custom error message... Searched on the internet but i did not find anything.
In my view:
#if (count($errors) > 0)
<div class="alert alert-danger">
<ul>
#foreach ($errors->all() as $error)
<li>{{ $error }}</li>
#endforeach
</ul>
</div>
#endif
My controller:
<?php
namespace App\Http\Controllers\Admin;
use App\User;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\Auth;
class UserController extends Controller
{
/**
* #param Request $request
* #return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
*/
public function login(Request $request)
{
$this->validate($request, [
'email' => 'required|email|exists:users,email',
'password' => 'required',
]);
if ($user = Auth::attempt([
'email' => $request->email,
'password' => $request->password
])) {
/** #var $user User */
if ($user->isAdmin()) {
return redirect()
->route('admin.dashboard');
}
}
// wrong email or password
return redirect('/admin/login');
}
}

Answer 1

First use Validator facade for validation and then
$inputs = $request->all();
$rules = array(
'email' => 'required|email|exists:users,email',
'password' => 'required',
);
$messages = array();
$validator = Validator::make($inputs,$rules,$messages);
$validator->after(function($validator) {
//do some stuff
$validator->errors()->add('error', 'error messgae');
})

Answer 2

custom error message :
return redirect('/admin/login')->withErrors([
'error_key' => 'error_message'
]);
and if you want flush old inputs :
return redirect('/admin/login')->withInput()->withErrors([
'error_key' => 'error_message'
]);

Answer 3

You should write this
<?php
namespace App\Http\Controllers\Admin;
use App\User;
use Illuminate\Http\Request;
use App\Http\Controllers\Controller;
use Illuminate\Support\Facades\Auth;
class UserController extends Controller
{
/**
* #param Request $request
* #return \Illuminate\Http\RedirectResponse|\Illuminate\Routing\Redirector
*/
public function login(Request $request)
{
$this->validate($request, [
'email' => 'required|email|exists:users,email',
'password' => 'required',
]);
if ($user = Auth::attempt([
'email' => $request->email,
'password' => $request->password
])) {
/** #var $user User */
if ($user->isAdmin()) {
return redirect()
->route('admin.dashboard');
}else {
return redirect('/admin/login')->>with('errors', 'Sorry!!! something went wrong. please try again.');
}
}else {
return redirect('/admin/login')->>with('errors', 'Sorry!!! something went wrong. please try again.');
}
// wrong email or password
return redirect('/admin/login');
}
}

Answer 4

You can add to errors while using Validator Facade for validation:
$validator = Validator::make(
[
'email' => $request->email,
'password' => $request->password
],
[
'email' => 'required|email|exists:users,email',
'password' => 'required',
]
);
$validator->errors()->add('custom-error', 'my custom error');