ObjectField Getter

Get a specific field of an object.

Additional aspects:

• If operator has no child element assigned, operator tries to call get<Attribute> on the current object.
• If child of operator returns a Concrete object (e.g. a many-to-one relation attribute), operator calls get<Attribute> on this object.
• If child of operator returns a list of Concrete objects (e.g. many-to-many-object relation attribute), operator calls get<Attribute> on all objects and returns an array of the values.
• With the Forward Attribute setting, the default principle for getting the data attribute value can be changed. Instead of getting the data attribute value of the main data object, a set Forward Attribute results in calling get<Forward Attribute> on the current data object first and then the actual data attribute value is calculated on its result. Thus, his would result in something similar to $object->get<Forward Attribute>()->get<Child Element>()->get<Attribute>().