function drupal_get_schema_versions

Returns an array of available schema versions for a module.

Parameters

$module: A module name.

Return value

If the module has updates, an array of available updates sorted by version. Otherwise, FALSE.

File

includes/install.inc, line 98

Code

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];
}