Unify validation exception formatting.

This unifies all validation error formatting into the exception handler
and out of Form Request. “Don’t Flash” is typically a global concept
that always applies to a list of fields for all pages in the
applications, so seemed to make sense to specify in one place instead
of each form.

Total control of the Form Request error response can still be gained by
overriding failedValidation and throwing a HttpResponseException with
whatever response you want.

src/Illuminate/Foundation/Exceptions/Handler.php

@@ -62,6 +62,16 @@ class Handler implements ExceptionHandlerContract
         \Illuminate\Validation\ValidationException::class,
     ];
 
+    /**
+     * A list of the inputs that are never flashed for validation exceptions.
+     *
+     * @var array
+     */
+    protected $dontFlash = [
+        'password',
+        'password_confirmation',
+    ];
+
     /**
      * Create a new exception handler instance.
      *
@@ -222,13 +232,14 @@ protected function convertValidationExceptionToResponse(ValidationException $e,
      */
     protected function invalid($request, ValidationException $exception)
     {
-        return redirect()->back()->withInput($request->except([
-            'password',
-            'password_confirmation',
-        ]))->withErrors(
-            $exception->validator->errors()->messages(),
-            $exception->errorBag
-        );
+        $url = $exception->redirectTo ?? url()->previous();
+
+        return redirect($url)
+                ->withInput($request->except($this->dontFlash))
+                ->withErrors(
+                    $exception->validator->errors()->messages(),
+                    $exception->errorBag
+                );
     }
 
     /**
@@ -242,7 +253,7 @@ protected function invalidJson($request, ValidationException $exception)
     {
         return response()->json([
             'message' => $exception->getMessage(),
-            'errors' => $exception->validator->errors()->messages(),
+            'errors' => $exception->errors()
         ], 422);
     }
 

src/Illuminate/Foundation/Http/FormRequest.php

@@ -59,13 +59,6 @@ class FormRequest extends Request implements ValidatesWhenResolved
      */
     protected $errorBag = 'default';
 
-    /**
-     * The input keys that should not be flashed on redirect.
-     *
-     * @var array
-     */
-    protected $dontFlash = ['password', 'password_confirmation'];
-
     /**
      * Get the validator instance for the request.
      *
@@ -122,51 +115,9 @@ protected function validationData()
      */
     protected function failedValidation(Validator $validator)
     {
-        throw new ValidationException($validator, $this->response(
-            $this->formatErrors($validator)
-        ));
-    }
-
-    /**
-     * Get the proper failed validation response for the request.
-     *
-     * @param  array  $errors
-     * @return \Symfony\Component\HttpFoundation\Response
-     */
-    public function response(array $errors)
-    {
-        if ($this->expectsJson()) {
-            return $this->jsonResponse($errors);
-        }
-
-        return $this->redirector->to($this->getRedirectUrl())
-                        ->withInput($this->except($this->dontFlash))
-                        ->withErrors($errors, $this->errorBag);
-    }
-
-    /**
-     * Get the proper failed validation JSON response for the request.
-     *
-     * @param  array  $errors
-     * @return \Illuminate\Http\JsonResponse
-     */
-    public function jsonResponse(array $errors)
-    {
-        return new JsonResponse([
-            'message' => 'The given data was invalid.',
-            'errors' => $errors,
-        ], 422);
-    }
-
-    /**
-     * Format the errors from the given Validator instance.
-     *
-     * @param  \Illuminate\Contracts\Validation\Validator  $validator
-     * @return array
-     */
-    protected function formatErrors(Validator $validator)
-    {
-        return $validator->getMessageBag()->toArray();
+        throw (new ValidationException($validator))
+                    ->errorBag($this->errorBag)
+                    ->redirectTo($this->getRedirectUrl());
     }
 
     /**

src/Illuminate/Validation/ValidationException.php

@@ -27,6 +27,13 @@ class ValidationException extends Exception
      */
     public $errorBag;
 
+    /**
+     * The path the client should be redirected to.
+     *
+     * @var string
+     */
+    public $redirectTo;
+
     /**
      * Create a new exception instance.
      *
@@ -44,6 +51,42 @@ public function __construct($validator, $response = null, $errorBag = 'default')
         $this->validator = $validator;
     }
 
+    /**
+     * Get all of the validation error messages.
+     *
+     * @return array
+     */
+    public function errors()
+    {
+        return $this->validator->errors()->messages();
+    }
+
+    /**
+     * Set the error bag on the exception.
+     *
+     * @param  string  $errorBag
+     * @return $this
+     */
+    public function errorBag($errorBag)
+    {
+        $this->errorBag = $errorBag;
+
+        return $this;
+    }
+
+    /**
+     * Set the URL to redirect to on a validation error.
+     *
+     * @param  string  $url
+     * @return string
+     */
+    public function redirectTo($url)
+    {
+        $this->redirectTo = $url;
+
+        return $this;
+    }
+
     /**
      * Get the underlying response instance.
      *