entity-relations-and-links

Entity references are temporary relationships, not permanent object references.

Storage

Use nullable entity IDs, network-safe entity forms, or established relation components. Do not serialize direct component references. Define whether the relation is one-way, bidirectional, unique, or many-to-many.

Lifecycle

Handle target deletion, source deletion, map transfer, container changes, body transfer, and component removal. Subscribe to relation-breaking events or revalidate before every use according to the lifetime and performance needs.

Ownership and authority

The server owns protected relationships such as account ownership, machine control, role assignment, or target locks. Clients may receive only the relation data needed for presentation.

Consistency

If both entities store the relationship, update both sides atomically or through one owning system. Prevent duplicate links and stale back-references.

Common failures

• deleted target remains cached;
• entity transfer preserves a relation that should reset;
• two systems each believe they own cleanup;
• client supplies an arbitrary linked entity;
• network state exposes hidden targets;
• save data restores an invalid entity ID.

Verification

Test link, relink, unlink, source deletion, target deletion, map transfer, reconnect, duplicate request, and invalid restored state.