Laravel 4 Property of non-object on Nginx - php

Question

I have the following code running on my laptop which is running a MAMP server (so apache). On my system it works absolutely fine, however, when I push it to my server it starts throwing "Trying to get property of non-object errors. The databases and migrations are all up to date, and reflect the setup on my laptop. I am wondering why this would be happening on my server and not my laptop. It also seems to happen randomly, which makes me think it's possibly a caching problem?
foreach($posts as $post){
$user = User::where("id","=",$post->posted_by)->first();
$response['posts'][] = [
'id' => $post->id,
'username' => $user->username, //causes problem
'firstname' => $user->name, //causes problem
'lastname' => $user->lastname, // causes problem
'images' => $post->getPostImages(),
'title' => $post->title,
'content' => $post->content,
'price' => $post->price,
'category' => Category::find($post->category_id)->title //causes problem
];
}

Answer 1

This is happening because a category object cant be found
you should change your code to this
foreach($posts as $post){
$user = User::where("id","=",$post->posted_by)->first();
//check if category id is set
if(!$post->category_id)
abort(500,'category_id is not set with Post: #'.$post->id);
//get the category
$category = Category::find($post->category_id);
//check if it found a category
if(!is_object($category)){
abort(500,'could not find Category: #'.$post->category_id);
}
$response['posts'][] = [
'id' => $post->id,
'username' => $user->username, //causes problem
'firstname' => $user->name, //causes problem
'lastname' => $user->lastname, // causes problem
'images' => $post->getPostImages(),
'title' => $post->title,
'content' => $post->content,
'price' => $post->price,
'category' => $category->title //causes problem
];
}
This change should help you find out what is missing :)