Clean way of checking if resource exists and if user can edit it - laravel

Question

I have two very common steps that I have to repeat in almost every CRUD method in my Controllers. I have my Users split into 2 groups ( Users, Administrators ). Now Users can edit, update and delete only their own entries while admins can do all the CRUD operations.
The second piece of code I find my self writing every time is checking if the resource exist which is repetitive and somewhat annoying.
Here is what I attempted:
<?php
class BaseController extends Controller
{
// Received Eloquent model each model has user_id field
public function authorize($resource)
{
// Check if currently logged in users id matches user_id
// value of the resource
if($resource->user_id !== CurrentUser::getUser()->id)
{
// Users id does not match with resource user_id check if user is admin
if(!CurrentUser::getGroup() === 'Admin')
{
// The id's do not match and user is not admin redirect him back to root
Session::flash('error', 'You cannot edit this resource');
return Redirect::to('/');
}
}
}
}
class CarController extends BaseController
{
public function edit($id)
{
// Attempt to find the resource
$car = Car::find($id);
// Check if found
if(!$car)
{
// Resource was not found
Session::flash('error', 'Resource was not found');
return Redirect::to('/cars');
}
// First check if user is allowed to edit the resource
// this however does not work because returned Redirect is simply ignored I would
// have to return boolean and then check it but...
$this->authorize($car);
// ... rest of the code
}
}
This would not be a problem if I had 3-4 methods but I have some 6-10 methods and as you can see this part takes some 20 lines of code add that 6-10 times not to mention it's repetitive to the point where it get's annoying.
I have tried to solve the problem using a filter but the problem is that I can pass the id to the filter but not get it to work in a way that I would pass the model as well.
There has to be a cleaner way to implement all this. I'm somewhat happy with authorize function/process but it would be awesome not having to call is every time possibly having some filter and each controller would define global variable/array of methods that require authorization.
As for checking if record was found I was hoping maybe a filter could be done to catch all RecordNotFound exceptions and redirect back to controllers index route with a message.

Answer 1

You can use findOrFail() and catch the exception in your BaseController and you also have two options:
try
{
$post = $this->post->findOrFail($id);
return View::make('posts.show', compact('post'));
}
catch(ModelNotFoundException $e)
{
return Redirect::route('posts.index');
}
Or
$post = $this->post->findOrFail($id);
return View::make('posts.show', compact('post'));
And a exception handler returning back to your form with the input:
App::error(function(ModelNotFoundException $exception)
{
return Redirect::back()->withErrors()->withInput();
});
Note that those are just examples, not took from your code.