Laravel 5.2 - Validation with API - php

Question

I am using Laravel 5.2 for validation with a REST JSON API.
I have a UserController that extends Controller and uses the ValidatesRequests trait.
Sample code:
$this->validate($request, [
'email' => 'required|email',
'password' => 'required|min:4|max:72',
'identifier' => 'required|min:4|max:36',
'role' => 'required|integer|exists:role,id',
]);
This throws an exception, so in my Exceptions/Handler.php I have this code:
public function render($request, Exception $e)
{
return response()->json([
'responseCode' => 1,
'responseTxt' => $e->getMessage(),
], 400);
}
However, when validating responseTxt is always:
Array
(
[responseCode] => 1
[responseTxt] => The given data failed to pass validation.
)
I have used Laravel 4.2 in the past and remember the validation errors providing more detail about what failed to validate.
How can I know which field failed validation and why?

Answer 1

A ValidationException gets thrown which gets rendered as a single generic message if the request wants JSON.
Instead of using the validate() method, manually invoke the validator, e.g.:
$validator = Validator::make($request->all(), [
'email' => 'required|email',
'password' => 'required|min:4|max:72',
'identifier' => 'required|min:4|max:36',
'role' => 'required|integer|exists:role,id',
]);
if ($validator->fails()) {
return new JsonResponse(['errors' => $validator->messages()], 422);
}
https://laravel.com/docs/5.2/validation#manually-creating-validators
As an aside, I'd recommend a 422 HTTP status code rather than a 400. A 400 usually implies malformed syntax. Something that causes a validation error usually means that the syntax was correct, but the data was not valid. 422 means "Unprocessable Entity"
https://www.rfc-editor.org/rfc/rfc4918#section-11.2

Answer 2

In Laravel 5.2 validate() method throws a Illuminate\Validation\ValidationException, so if you want to get the response use getResponse() instead getMessage().
For example, an easy way to handle this exception could be doing something like this:
try{
$this->validate($request, [
'email' => 'required|email',
'password' => 'required|min:4|max:72',
'identifier' => 'required|min:4|max:36',
'role' => 'required|integer|exists:role,id'
]);
}catch( \Illuminate\Validation\ValidationException $e ){
return $e->getResponse();
}