// In post model are we are checking whether user has liked it:
// contains is a collection method which allows to look at the inside of the collection
// with collectiong you are looking at a particular key (user_id), and checking if the $user->id is within the collection
// then it will return a true or false
 
// POST MODEL: 
public function likedBy(User $user){
      return $this->likes->contains('user_id', $user->id);
    }

//POSTLIKECONTROLLER
 public function store($id, Request $request){
// this is activating when you press the submit button for like

        $this->middleware(['auth']);


        $post = Post::find($id);

        if ($post->likedBy($request->user())){
            return back(); 
        }
        
        $post->likes()->create([
            'user_id' => $request->user()->id,
        ]);
        return back();