/**
* Get a context instance as an object, from a given context id.
*
* @static
* @param int $id context id
* @param int $strictness IGNORE_MISSING means compatible mode, false returned if record not found, debug message if more found;
* MUST_EXIST means throw exception if no record found
* @return context|bool the context object or false if not found
*/
public static function instance_by_id($id, $strictness = MUST_EXIST)
{
global $DB;
if (get_called_class() !== 'context' and get_called_class() !== 'context_helper') {
// some devs might confuse context->id and instanceid, better prevent these mistakes completely
throw new coding_exception('use only context::instance_by_id() for real context levels use ::instance() methods');
}
if ($id == SYSCONTEXTID) {
return context_system::instance(0, $strictness);
}
if (is_array($id) or is_object($id) or empty($id)) {
throw new coding_exception('Invalid context id specified context::instance_by_id()');
}
if ($context = context::cache_get_by_id($id)) {
return $context;
}
if ($record = $DB->get_record('context', array('id' => $id), '*', $strictness)) {
return context::create_instance_from_record($record);
}
return false;
}
