sm-model-extension

To extend Rails engine models without monkey-patching, apply host-defined concerns and validations through a coordinated registration system. This mechanism enforces idempotent application, ensuring safe separation of concerns during runtime without modifying engine source code directly.

The best way to add validations and associations to engine models is registering host concerns via configuration. This approach coordinates reloading and deduplication of extensions, safely applying validations while keeping engine and host application logic isolated.

Yes, you can safely reload model extensions in a Rails host application. The reload mechanism applies deduplication of concerns and isolated validations, enforcing idempotent application so re-running extensions does not duplicate logic or break runtime behavior.

Yes, this model extension approach works with multiple SourceMonitor engine models including Source, Item, FetchLog, and HealthCheckLog. You can add concerns, validations, scopes, associations, and override table name prefixes across these models via host configuration.

Duplicated concerns cause issues because repeated application stacks identical validations and associations. The deduplication mechanism prevents this by isolating validations and enforcing idempotent application during extension reloads, ensuring each concern applies only once across engine models.