Dynamically select properties from PHP object - php

Question

I have an array of PHP objects (lets say orders) which have arrays of items like so (JSON for ease of notation):
$orders = [
{
id: 87,
user_id: 6,
menu_id: 9,
items: [
{
id: 1,
name: "Item 1",
}
]
},
{
id: 88,
user_id: 3,
menu_id: 6,
items: [
{
id: 2,
name: "Item 2",
}
]
}
]
I'm trying to make a CSV row with titles of this kind of array. I'm using a keyed array like so:
$settings = [
'Order ID' => 'id',
'User ID' => 'user_id'
];
So now I can go...
$csv = [];
$csv[] = array_keys($settings);
foreach($orders as $order):
$csv_row = [];
foreach($settings as $column);
$csv_row[] = $order->{$column};
endforeach;
$csv[] = $csv_row;
endforeach;
This gives me:
[ 'Order ID', 'User ID' ]
[ '87', '6' ]
[ '88', '3' ]
Is there any way I can dynamically access the 'deeper' variables? i.e. $order->items[0]->name, in a similar way to the curly bracket notation? I need to do it dynamically as there are lots of different object and relations that I need to export as CSV files.
P.S. Its really late – sorry if this is a crazy question

Answer 1

You can't use the curly braces notation to get deeper than one level. What you could do is to use a helper function that would let you fetch values by multi-level key.
An example function could be:
function getByPath($value, array $path)
{
if (empty($path)) return $value;
if (!is_array($value)) return;
if (array_key_exists($path[0], $value)) return getByPath($value[$path[0]], array_slice($path, 1));
}
Example usage pattern for your case could be:
$settings = [
'Order ID' => ['id'],
'User ID' => ['user', 'id'],
'User Name' => ['user', 'name'],
'Item 0 Name' => ['item', 0, 'name'],
'Item 0 Price' => ['item', 0, 'price']
];
foreach($settings as $path);
$csv_row[] = getByPath($order, $path);
endforeach;