An EOControlAssociation also sets itself as the control's delegate in order to receive various editing and validation messages. In the com.apple.yellow.eointerface package, any outlets an association claims cannot be used for other purposes. A button acting as an EOControlAssociation's display object, for example, has its target outlet dimmed. See the EOMasterDetailAssociation class specification for more information on master-detail configurations. Although an EOAssociation has only one display object it may have any number of aspects.
Aspects define the EODisplayGroup characteristics that the association observes.
Aspects are bound to a display group by a key of the enterprise objects contained by the association. Depending upon a given EOAssociation subclass, aspects may be optional or mandatory. They might all have to be bound to a single EODisplayGroup or they may span several. Some aspects can be mutually exclusive. On the display side, aspects are typically bound to visible facets of the EOAssociation's display object, such as the value or values it displays and any interactive state.