Returns an array of available schema versions for a module.
$module: A module name.
If the module has updates, an array of available updates sorted by version. Otherwise, FALSE.
function drupal_get_schema_versions($module) {
$updates =& drupal_static(__FUNCTION__, NULL);
if (!isset($updates[$module])) {
$updates = array();
foreach (module_list() as $loaded_module) {
$updates[$loaded_module] = array();
}
// Prepare regular expression to match all possible defined hook_update_N().
$regexp = '/^(?P<module>.+)_update_(?P<version>\\d+)$/';
$functions = get_defined_functions();
// Narrow this down to functions ending with an integer, since all
// hook_update_N() functions end this way, and there are other
// possible functions which match '_update_'. We use preg_grep() here
// instead of foreaching through all defined functions, since the loop
// through all PHP functions can take significant page execution time
// and this function is called on every administrative page via
// system_requirements().
foreach (preg_grep('/_\\d+$/', $functions['user']) as $function) {
// If this function is a module update function, add it to the list of
// module updates.
if (preg_match($regexp, $function, $matches)) {
$updates[$matches['module']][] = $matches['version'];
}
}
// Ensure that updates are applied in numerical order.
foreach ($updates as &$module_updates) {
sort($module_updates, SORT_NUMERIC);
}
}
return empty($updates[$module]) ? FALSE : $updates[$module];
}