Laravel - Unique Rules Validation - GetMessages Does Not Exist

I have a simple quiz app I'm writing where there is a series of challenges (Easy, Medium, Hard), each with their own questions.

The questions to be added should be unique.

I have the following code to "store" the data

$v = ChallengeQuests::validate(Input::all());

        if ( $v->passes() ) {
            print 'validate passed';
            $record = ChallengeQuests::create(array(
                'challenge_id'=> (int) Input::get('challenge_id'),
                'question_id'=> (int) Input::get('question_id')
            ));
            $record->save();
            return redirect()->to($url['redirects_to']);
        } else {
            print 'error';
            print_r($v->getMessages());
            return Redirect::to('/')->withErrors($v->getMessages());
        }

In my model I have a validation method

// model
class ChallengeQuests extends Model
{
    //
    protected $table = 'challengequests';
    protected $fillable=[
        'challenge_id',
        'question_id'
    ];

    public static function validate($input) {
        $rules = array(
            'challenge_id' => 'Required|Integer',
            'question_id' => 'Required|Integer|Unique:questions,id'
        );

        return Validator::make($input, $rules);
    }
}

But when I run my code, Laravel complains

BadMethodCallException in Validator.php line 3016:
Method [getMessages] does not exist.

I'm wanting it so that the question_id is unique.

What am I doing wrong?

Edit:

I am using:

use Illuminate\Support\Facades\Validator;
use Illuminate\Support\Facades\Input;

Stack trace:

BadMethodCallException in Validator.php line 3016:
Method [getMessages] does not exist.
in Validator.php line 3016
at Validator->__call('getMessages', array()) in ChallengeQuestionsController.php line 78
at ChallengeQuestionsController->store(object(Request))
at call_user_func_array(array(object(ChallengeQuestionsController), 'store'), array(object(Request))) in Controller.php line 80
at Controller->callAction('store', array(object(Request))) in ControllerDispatcher.php line 146
at ControllerDispatcher->call(object(ChallengeQuestionsController), object(Route), 'store') in ControllerDispatcher.php line 94
at ControllerDispatcher->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in ControllerDispatcher.php line 96
at ControllerDispatcher->callWithinStack(object(ChallengeQuestionsController), object(Route), object(Request), 'store') in ControllerDispatcher.php line 54
at ControllerDispatcher->dispatch(object(Route), object(Request), 'App\Http\Controllers\ChallengeQuestionsController', 'store') in Route.php line 174
at Route->runController(object(Request)) in Route.php line 140
at Route->run(object(Request)) in Router.php line 724
at Router->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in Router.php line 726
at Router->runRouteWithinStack(object(Route), object(Request)) in Router.php line 699
at Router->dispatchToRoute(object(Request)) in Router.php line 675
at Router->dispatch(object(Request)) in Kernel.php line 246
at Kernel->Illuminate\Foundation\Http\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 52
at Pipeline->Illuminate\Routing\{closure}(object(Request)) in CheckForMaintenanceMode.php line 44
at CheckForMaintenanceMode->handle(object(Request), object(Closure))
at call_user_func_array(array(object(CheckForMaintenanceMode), 'handle'), array(object(Request), object(Closure))) in Pipeline.php line 124
at Pipeline->Illuminate\Pipeline\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 32
at Pipeline->Illuminate\Routing\{closure}(object(Request))
at call_user_func(object(Closure), object(Request)) in Pipeline.php line 102
at Pipeline->then(object(Closure)) in Kernel.php line 132
at Kernel->sendRequestThroughRouter(object(Request)) in Kernel.php line 99
at Kernel->handle(object(Request)) in index.php line 53
at require_once('/Applications/XAMPP/xamppfiles/htdocs/laravel/scquiz/public/index.php') in server.php line 21

The correct method used to get the validation messages is not getMessages() it's messages(), so your code should look like this:

return Redirect::to('/')->withErrors($v->messages());

Also if you're using Laravel 5, you might want to look into using Form Request Validation which does the same thing you're trying to achieve but in a nicer way, and handles the validation on a different layer, taking care of passing the errors and page redirection for you.

By using a Form Request in your case, the controller method would be reduced to this:

public function store(ChallangeQuestsFormRequest $request)
{
    ChallengeQuests::create($request->only('challenge_id', 'question_id'));

    return redirect()->to($url['redirects_to']);
}

Since the rules and validation as well as redirection in case of an error, would be handled by the ChallangeQuestsFormRequest class. Also, using create to create a model entry will automatically save the entry, so there's no need to use save on the result of create.