Better way to dynamically access values in nested array - php

Question

I need a way to dynamically access values in a nested array using an index map. What i want to achieve is looping over an array with data and extract some values that can be in any level of the nesting and save it to a bi-dimensional array.
So far I've come up with the following code, which works quite well, but I was wondering if there is a more efficient way to do this.
<?php
// Sample data
$array = array();
$array[0]['code'] = "ABC123";
$array[0]['ship'] = array("name" => "Fortune", "code" => 'FA');
$array[0]['departure'] = array("port" => "Amsterdam", "code" => "AMS");
$array[0]['document'] = array("type" => "Passport", "data" => array("valid" => '2022-03-18', 'number' => 'AX123456') );
$array[1]['code'] = "QWERT67";
$array[1]['ship'] = array("name" => "Dream", "code" => 'DR');
$array[1]['departure'] = array("port" => "Barcelona", "code" => "BRC");
$array[1]['document'] = array("type" => "Passport", "data" => array("valid" => '2024-12-09', 'number' => 'DF908978') );
// map of indexes of $array I need in my final result array. The levels of the nested indexes is subdivided by ":"
$map = array("code", "ship:name", "departure:port", "document:type", "document:data:number");
$result = array();
// loop array for rows of data
foreach($array as $i => $row){
// loop map for indexes
foreach($map as $index){
// extract specific nested values from $row and save them in 2-dim array $result
$result[$i][$index] = xpath_array($index, $row);
}
}
// print out result
print_r($result);
// takes path to value in $array and returns given value
function xpath_array($xpath, $array){
$tmp = array();
// path is subdivded by ":"
$elems = explode(":", $xpath);
foreach($elems as $i => $elem){
// if first (or ony) iteration take root value from array and put it in $tmp
if($i == 0){
$tmp = $array[$elem];
}else{
// other iterations (if any) dig in deeper into the nested array until last item is reached
$tmp = $tmp[$elem];
}
}
// return found item (can be value or array)
return $tmp;
}
Any suggestion?

Answer 1

This was quite tricky for me, i used Recursive function, first we normalize array keys to obtain key as you want like this document:type, then we normalize array to obtain all at same level :
/**
* #param array $array
* #param string|null $key
*
* #return array
*/
function normalizeKey(array $array, ?string $key = ''): array
{
$result = [];
foreach ($array as $k => $v) {
$index = !empty($key) && !\is_numeric($key) ? $key.':'.$k : $k;
if (true === \is_array($v)) {
$result[$k] = normalizeKey($v, $index);
continue;
}
$result[$index] = $v;
}
return $result;
}
/**
* #param array $item
* #param int $level
*
* #return array
*/
function normalizeStructure(array $item, int $level = 0): array
{
foreach ($item as $k => $v) {
$level = isset($v['code']) ? 0 : $level;
if (true === \is_array($v) && 0 === $level) {
$item[$k] = normalizeStructure($v, ++$level);
continue;
}
if (true === \is_array($v) && 0 < $level) {
$item = \array_merge($item, normalizeStructure($v, ++$level));
unset($item[$k]);
continue;
}
}
return $item;
}
$data = normalizeStructure(normalizeKey($array));
I edited your data set to add more nests:
// Sample data
$array = array();
$array[0]['code'] = "ABC123";
$array[0]['ship'] = array("name" => "Fortune", "code" => 'FA');
$array[0]['departure'] = array("port" => "Amsterdam", "code" => "AMS");
$array[0]['document'] = array("type" => "Passport", "data" => array("valid" => '2022-03-18', 'number' => 'AX123456'));
$array[1]['code'] = "QWERT67";
$array[1]['ship'] = array("name" => "Dream", "code" => 'DR');
$array[1]['departure'] = array("port" => "Barcelona", "code" => "BRC");
$array[1]['document'] = array("type" => "Passport", "data" => array("valid" => '2024-12-09', 'number' => 'DF908978', 'check' => ['number' => '998', 'code' => 'itsWell', 'inception' => ['border' => 'finalInception']]));
With these data, you should finally receive this result:
/*
Array
(
[0] => Array
(
[code] => ABC123
[ship:name] => Fortune
[ship:code] => FA
[departure:port] => Amsterdam
[departure:code] => AMS
[document:type] => Passport
[document:data:valid] => 2022-03-18
[document:data:number] => AX123456
)
[1] => Array
(
[code] => QWERT67
[ship:name] => Dream
[ship:code] => DR
[departure:port] => Barcelona
[departure:code] => BRC
[document:type] => Passport
[document:data:valid] => 2024-12-09
[document:data:number] => DF908978
[document:data:check:number] => 998
[document:data:check:code] => itsWell
[document:data:check:inception:border] => finalInception
)
)
*/
Recursivity seems to be like Inception, everything is nested and you can lose your mind in 😆, mine was already lost in.