teemill.php

<?php
// Array given from 'api'
$arr = array(
    "action: Added; quantity: 1; item_code: RNA1; product_name: Mens Organic T-Shirt; colour: White; size: XL;",
    "action: Subtracted; quantity: 7; item_code: RNC1; product_name: Kids Basic T-shirt; colour: Denim Blue; size: 3-4y",
    "action: Added; quantity: 20; item_code: RNV1; product_name: Gift Voucher; style: Mens; value: £20"
);

// New array to hold the final output
$newArr = array();

// Loop through each array item/line
foreach ($arr as $line) {
    // Split the current item/line by the ; character into a new array, which splits the string into pairs
    $tempArr = 	explode ('; ', $line);
    // Loop through the new array created from the split
    foreach ($tempArr as $pair) {
        // Create a list using a key/value pair
        // The $k comes from item [0] of the array created from the split of the : charater
        // The $v comes from item [1] of the array
        list ($k,$v) = explode (': ',$pair);
        // Temp array that assigns the key ($k) to the value of $v
        $pairs[$k] = $v;
    }
    // Push the temp array into the output array
    array_push($newArr, $pairs);
}
// Print the output array
print_r($newArr);

?>