PHP - Sort a multidimensional arrays subsubarray from value - php

Question

Array
array (
[0] => array
(
[field1] => 'name'
[field2] => 'text'
[field3] => array
(
[0] => array
(
[text] => 'This arrays order is to be kept!'
[name] => 'Only sort the sub-sub-array below!'
[order] => ''
)
)
)
[1] => array
(
[field1] => 'name'
[field2] => 'text'
[field3] => array
(
[0] => array
(
[text] => '2014'
[name] => 'Dummy!'
[order] => '1'
)
[1] => array
(
[text] => '2013'
[name] => 'Try me!'
[order] => '2'
)
[2] => array
(
[text] => '1985'
[name] => 'Help!'
[order] => '5'
)
[3] => array
(
[text] => '2002'
[name] => 'Please!'
[order] => '4'
)
[4] => array
(
[text] => '2007'
[name] => 'Order!'
[order] => '3'
)
)
)
...
Goal
I want to keep the 1st and 2nd level array and it's values as is. I need to sort the keys in the 2nd sub-sub-array by the value in theorder-field. So where it says the years, that sub-sub-array should be sorted ASC or DESC. and all other keys/values/structure/map should be kept as is.
Sorted array:
array (
[0] => array
(
[field1] => 'name'
[field2] => 'text'
[field3] => array
(
[0] => array
(
[text] => 'This arrays order is to be kept!'
[name] => 'Only sort the sub-sub-array below!'
[order] => ''
)
)
)
[1] => array
(
[field1] => 'name'
[field2] => 'text'
[field3] => array
(
[0] => array
(
[text] => '2014'
[name] => 'Dummy!'
[order] => '1'
)
[1] => array
(
[text] => '2013'
[name] => 'Try me!'
[order] => '2'
)
[2] => array
(
[text] => '2007'
[name] => 'Order!'
[order] => '3'
)
[3] => array
(
[text] => '2002'
[name] => 'Please!'
[order] => '4'
)
[4] => array
(
[text] => '1985'
[name] => 'Help!'
[order] => '5'
)
)
)
Help
I've spent hours and hours of trying different custom solutions, mostly based on usort() but I've also done it knowing that none of those Q&A were describing the situation I've got.
I'm starting to doubt that it's even possible.
Does anyone know if it is? And if so, can you please shed some light or provide a hint/tutorial/example for demonstration?
Laravel 5.1
I'm retrieving this from a Laravel Model and using toArray();
Is there is a better way to achieve this in Laravel I would be glad to know.

Answer 1

If the sub-subarray you are wanting to sort is always identified by the same key, you can just usort the contents of that key.
foreach ($test as &$value) {
// Using a (^) reference to each value will sort the existing
// array instead of creating a sorted copy.
usort($value['field3'], function($a, $b) {
// You can use an anonymous function like this for the usort comparison function.
if ($a['order'] < $b['order']) return -1;
if ($a['order'] == $b['order']) return 0;
// In case of 'order' ties, you may want to add a comparison of a different key
return 1; // $a['order'] must be > $b['order'] at this point
});
}
Note that the comparison function used in usort:
must return an integer less than, equal to, or greater than zero if the first argument is considered to be respectively less than, equal to, or greater than the second.
It may be better to do this using Laravel, because the database will most likely be able to do this sorting faster than PHP will, but we would need to know much more about your model setup to figure that out and that sounds like basically a totally different question.

Answer 2

If I understood the problem correctly, this could be a solution (in these examples $arr is the variable holding the array):
function cmp($a, $b)
{
return ($a['order'] < $b['order']) ? -1 : 1;
}
foreach($arr as $key => $subarr){
foreach($subarr as $key2 => $subsubarr){
if(is_array($subsubarr)){
usort($subsubarr,"cmp");
$subarr[$key2] = $subsubarr;
}
}
$arr[$key] = $subarr;
}
or
function cmp($a, $b)
{
return ($a['order'] < $b['order']) ? -1 : 1;
}
foreach($arr as &$subarr){
foreach($subarr as &$subsubarr){
if(is_array($subsubarr)){
usort($subsubarr,"cmp");
}
}
}