EObjects

EObjects are the base interface for all modeled objects in the Eclipse Modeling Framework (EMF). Every instance that conforms to an Ecore model is an EObject, and its concrete type is defined by an EClass. An EObject provides access to its meta-information through its eClass, and to its features through EAttributes and EReferences defined in that EClass.

Each EObject can participate in containment hierarchies and be part of a Resource. The eContainer() method returns the containing object, and eResource() returns the owning Resource, while eContainingFeature() indicates the feature that holds it. This structural information supports navigation, serialization, and lifecycle management within EMF models.

EMF exposes a reflective API on EObject via eGet, eSet, eIsSet, and eUnset, which can take either feature identifiers or structural features. This enables dynamic model manipulation without the need for generated code for every class, while generated code can provide type-safe accessors on top of this API. EObject also supports change notification through adapters and the eNotify mechanism, allowing listeners to respond to model changes.

Concrete implementations of the EObject interface include EObjectImpl and MinimalEObjectImpl, which provide concrete behavior for storage, containment, and notification. EMF supports proxies, enabling cross-resource references to be resolved lazily. When a proxy is resolved, the target EObject is loaded from its resource. EObjects are designed to be serializable by EMF Resources (for example XMI) via a ResourceSet.

In summary, EObjects form the core abstraction of EMF models, enabling uniform access to type information, features, containment, lifecycle, notification, and persistence for both static and dynamic modeling approaches.