Laravel method attributesToArray() not running on production - php

Question

I'm deploying my application to my production environment and it's not working as expected. I've narrowed the issue down to one line inside this loop in my controller;
foreach($temp_table_data as $a_payment) {
//array_push($payments, $a_payment->payment); //big collection object
array_push($payments, $a_payment->payment->first()->attributesToArray()); //smaller object
}
The error I get is call to a member function attributesToArray() on a non object. This seems crazy to be because - as the old saying goes - it works fine on my machine.
My dev. environment is Ubuntu trusty64 on PHP 5.5.21 and my production is RedHat Linux PHP 5.5.11. I thought these differences were very minor (maybe I'm wrong?).
If I do a print_r($temp_table_data() then I get a big collection returned. The same on both servers. So at some point it just stops liking either payment (that's a method) or first()
Here is partial of my TempTable.php Model with the payment method;
public function payment(){
return $this->hasMany('App\Models\Payment', 'Vendor ZIP', 'postcode');
}
And my Payment.php model (part of it);
class Payment extends Model {
protected $table = 'headquarters_data';
public function tempTable()
{
return $this->belongsTo('App\Models\TempTable', 'postcode', 'Vendor ZIP');
}

Answer 1

One of the tempTable models doesnt have a Payment and the attributesToArray() method is failing.
Try this and see if it works.
foreach($temp_table_data as $a_payment) {
$payment = $a_payment->payment->first();
if(!is_null($payment)){
$payments[] = $payment->attributesToArray();
}
}

Answer 2

the problem is that in production you have probably changed the data in your database and calling to first() method returns null then you are trying to call attributesToArray() on a null, which is wrong!
you should do a isset() function before calling attributesToArray().
if(isset($a_payment->payment->first()))
array_push($payments, $a_payment->payment->first()->attributesToArray());