Laravel 5: How to custom error function in validator request? - laravel-5.1

Question

My custom validation request:
<?php
namespace App\Http\Requests;
use Illuminate\Contracts\Validation\Validator;
class AccountPostRequest extends Request
{
public function authorize() {
return true;
}
public function rules() {
return [
'username' => 'required|alpha_dash'
];
}
public function message() {
return [
'username.required' => 'input your email',
'username.alpha_dash' => 'email format error'
];
}
protected function formatErrors(Validator $validator) {
return $validator->errors()->all();
}
//here is my question, how to invoke this callback when the validation fails,
//or has any other function like the "before" or "after" filters
protected function callback(Validator $validator) {
if ($validator->fails()) {
//do some thing
} else {
//do some thins
}
}
}
?>
My controller:
namespace App\Http\Controllers\Admin;
use App\Http\Controllers\Controller;
use App\Http\Requests\AccountPostRequest;
class AccountController extends Controller
{
public function login(AccountPostRequest $request) {
//...
}
}
As you know, if the request validate failed, it will not continue to execute the login function of AccountController.
My question is how to invoke the callback when the validation fails, or has any other function like the "before" or "after" filters?

Answer 1

All form request that are validated are going through a pipeline in Illuminate\Foundation\Http\FormRequest which uses a trait called Illuminate\Validation\ValidatesWhenResolvedTrait. This class has contains all the classes you may want to modify and overwrite.
For example, you can simply copy and paste the failedValidation method and customize it.
/**
* Handle a failed validation attempt.
*
* #param \Illuminate\Contracts\Validation\Validator $validator
* #return mixed
*/
protected function failedValidation(Validator $validator)
{
// Do something awesome...
}