PHP context::get_child_contexts示例

/**
 * This is really slow!!! do not use above course context level
 *
 * @deprecated since 2.2
 * @param int $roleid
 * @param context $context
 * @return array
 */
function get_role_context_caps($roleid, context $context)
{
    global $DB;
    //this is really slow!!!! - do not use above course context level!
    $result = array();
    $result[$context->id] = array();
    // first emulate the parent context capabilities merging into context
    $searchcontexts = array_reverse($context->get_parent_context_ids(true));
    foreach ($searchcontexts as $cid) {
        if ($capabilities = $DB->get_records('role_capabilities', array('roleid' => $roleid, 'contextid' => $cid))) {
            foreach ($capabilities as $cap) {
                if (!array_key_exists($cap->capability, $result[$context->id])) {
                    $result[$context->id][$cap->capability] = 0;
                }
                $result[$context->id][$cap->capability] += $cap->permission;
            }
        }
    }
    // now go through the contexts bellow given context
    $searchcontexts = array_keys($context->get_child_contexts());
    foreach ($searchcontexts as $cid) {
        if ($capabilities = $DB->get_records('role_capabilities', array('roleid' => $roleid, 'contextid' => $cid))) {
            foreach ($capabilities as $cap) {
                if (!array_key_exists($cap->contextid, $result)) {
                    $result[$cap->contextid] = array();
                }
                $result[$cap->contextid][$cap->capability] = $cap->permission;
            }
        }
    }
    return $result;
}