Function extractDefListOrFactory

packages/core/src/render3/definition.ts:653–674

(
  dependencies: TypeOrFactory<DependencyTypeList> | undefined,
  defExtractor: (type: Type<unknown>) => T | null,
)

}

export function extractDefListOrFactory<T>(
  dependencies: TypeOrFactory<DependencyTypeList> | undefined,
  defExtractor: (type: Type<unknown>) => T | null,
): (() => T[]) | T[] | null {
  if (!dependencies) {
    return null;
  }

  return () => {
    const resolvedDependencies = typeof dependencies === 'function' ? dependencies() : dependencies;
    const result: T[] = [];

    for (const dep of resolvedDependencies) {
      const definition = defExtractor(dep);
      if (definition !== null) {
        result.push(definition);
      }
    }

    return result;
  };
}

/**
 * A map that contains the generated component IDs and type.