Partial Field Validation

Describe and resolve fields

API signatures:

• FormInstance::describeFields(): array
• FormInstance::resolveField(string $identifier): ?array
• FormManager::describeFields(string $formKey, ?string $version = null): array
• FormManager::resolveField(string $formKey, string $identifier, ?string $version = null): ?array
• ScopedFormManager::describeFields(string $formKey, ?string $version = null): array
• ScopedFormManager::resolveField(string $formKey, string $identifier, ?string $version = null): ?array

Descriptor shape:

• name (canonical key)
• field_key, key, id, label (nullable)
• type
• required (bool)
• rules (array)
• options (array, empty when not relevant)
• default (mixed)
• lookup_keys (array<string>, ordered unique aliases used by resolver)

Validate partial field subsets

API signatures:

• FormInstance::validateFields(array $payload, array $onlyFields = [], ?string $locale = null): array
• FormManager::validateFields(string $formKey, array $payload, array $onlyFields = [], ?string $version = null, ?string $locale = null): array
• ScopedFormManager::validateFields(string $formKey, array $payload, array $onlyFields = [], ?string $version = null, ?string $locale = null): array

Behavior:

• onlyFields = []: validate only keys present in payload that resolve to known fields
• onlyFields != []: validate strictly the requested subset
• identifiers in onlyFields may be aliases (name, field_key, key, id)
• errors are returned by canonical name
• unknown payload keys are ignored in this partial flow
• unresolved identifiers in onlyFields return explicit per-identifier errors