/**
* Get or set the relation identified by its name.
*
* If second parameter is null, it works like a getter.
* It works like a setter if second parameter is not null.
*
* @param $name The name of the relation.
* @param $relation The relation to set instead
*
* @return object A Relation object.
* @throw SimpleAR\Exception if used as getter and $relationName is unknown.
*/
public static function relation($name, Relation $relation = null)
{
if ($relation === null) {
if (!isset(static::$_relations[$name])) {
throw new Exception('Relation "' . $name . '" does not exist for class "' . get_called_class() . '".');
}
// Avoid array accesses.
$val =& static::$_relations[$name];
// If relation is not yet initlialized, do it.
if (!$val instanceof Relation) {
$val = Relation::forge($name, $val, get_called_class());
}
// Return the Relation object.
return $val;
} else {
static::$_relations[$name] = $relation;
}
}
