functions to get/set values in multidimensional arrays dynamically - php

Question

I am trying to write a shoping cart in php and I have a problem with get/set values in multidimentional arrays.
I keep the current order in $_SESSION['basket']. It looks like that:
[basket] => Array
(
[0] => Array
(
[pid] => 3
[name] => Camera
[price] => 200.99
[quantity] => 1
)
[1] => Array
(
[pid] => 5
[name] => Computer
[price] => 320.99
[quantity] => 1
[extras] => Array
(
[0] => Array
(
[pid] => 86
[name] => RAM
[price] => 99
[qty] => 1
)
[1] => Array
(
[pid] => 98
[name] => CD-ROM
[price] => 19.99
[qty] => 1
)
)
)
)
Every item is stored as a subarray. I have a function, which checks if a given item exists in the basket array and returns the path to it. For example, if I want to check for a product with id 98 (CD-Rom), the function returns the following path: 1:extras:1.
I cant figure out how to use the path if I want to get or a set a value in the array. Is it possible to construct the path to an array key, without the use of eval()? I have these functions:
function get_val($array, $path, $key) {
//some code
return eval('return '.$array.$path.$key.';');
}
So, $price = get_val($_SESSION['basket'], $path, 'price'); should return the price for CD-ROM (19.99)
function set_val($array, $path, $key, $value) {
//some code
$str = eval(''.$array.$path.$key.';');
$str = $value;
}
set_val($_SESSION['basket'], $path, 'price', '30'); will set the price for CD-ROM to 30.
Is there a better way for doing this?
Thank you.

Answer 1

Here you go a code I have finetuned some time ago:
function get_val($array,$path) {
for($i=$array; $key=array_shift($path); $i=$i[$key]) {
if(!isset($i[$key])) return null;
}
return $i;
}
function set_val(&$array,$path,$val) {
for($i=&$array; $key=array_shift($path); $i=&$i[$key]) {
if(!isset($i[$key])) $i[$key] = array();
}
$i = $val;
}
See this test example, I believe it is what you are looking for:
$data = array("x"=>array("y"=>array("z"=>"foo")));
echo get_val($data,array("x","y","z")); // foo
set_val($data,array("x","y","u"),"bar"); // $data["x"]["y"]["u"] = "bar";

Answer 2

Yesterday people down voted me because I got this function. And today I hope someone can use it.
Getting values
Below function will return the value of the path you define.
function getPath($path, $array)
{
$path = split(":", $path);
$active = $array;
foreach($path as $key => $part)
{
$active = $active[$part];
}
return $active;
}
$array = array(array(array(array("product" => array( "id" => 12 )))));
// Give the path to the data you want, by keys
echo getPath("0:0:0:product:id", $array);
Which echo's
12
And setting values
function setPath($path, &$array, $mykey, $value)
{
$path = split(":", $path);
$active =& $array;
foreach($path as $key => $part)
{
$active =& $active[$part];
}
$active[$mykey] = $value;
return $active;
}
$array = array(array(array(array("product" => array( "id" => 12 )))));
// Give the path to the data you want, by keys
setPath("0:0:0:product", $array, "price", 100);
print_r($array);
Results:
Array ( [0] => Array ( [0] => Array ( [0] => Array ( [product] => Array ( [id] => 12 [price] => 100 ) ) ) ) )