Angular Best Practices

Register once per feature

Register stable policies during feature initialization. Use replacePolicy() only for generated fields.

Keep paths aligned

validateModel, policy paths, and model shape must describe the same property.

Prefer display strategies

Use a display strategy for CSS classes and error containers instead of duplicating markup in every control.

Clean up dynamic registrations

Lazy-loaded features and generated forms should unregister policies, groups, and stale validation state when they are destroyed.

Performance

Validate focused fields during interaction and whole policies during submit. For large generated forms, build policy metadata once per generation and validate groups when possible.

Testing

Test directives, summaries, group status, invalid classes, and valid submission behavior.