calculate product variants based on option groups and options

Question

I am writing an ecommerce site, and need a good way to calculate product variations. The Site has products, products can have many option groups, option groups can have many

Answer 1

If this is an e-commerce site my guess is your option groups are already in an SQL database so why not just let SQL do the combinations for you.

SELECT Size.Name, Color.Name, Material.Name FROM Size, Color, Material

But what if you had all your options in one table with a foreign key to the group it's in...

SELECT r1.Name, r2.Name, r3.Name 
FROM Options r1, Options r2, Options r3
WHERE r1.GroupID = 1 -- id for Size
    AND r2.GroupID = 2 -- id for Color
    AND r3.GroupID = 3 -- id for Material

Once you have an array containing the group IDs generating the SQL statement above is trivial (just concatenating a few string implodes).

Answer 2

This should do the trick:

<?

$data[]=array('shirt');
$data[]=array('red','yellow','black');
$data[]=array('small','medium','large');

$combos=possible_combos($data);

//calculate all the possible comobos creatable from a given choices array
function possible_combos($groups, $prefix='') {
    $result = array();
    $group = array_shift($groups);
    foreach($group as $selected) {
        if($groups) {
            $result = array_merge($result, possible_combos($groups, $prefix . $selected. ' '));
        } else {
            $result[] = $prefix . $selected;
        }
    }
    return $result;
}

echo count($combos) . "\n";
print_r($combos);

Tested: http://www.ideone.com/NZE5S