Persistence Factories Architectural Design Pattern

Abstract

Each screen of the user interface of a mobile or desktop application coordinates one or more use cases. Each one of those use cases may need to access different entities of the persistent data. It is a common practice to inject a provider for each of those entities of the model. Thus, the more use cases the view deals with, the more entity providers need to be injected. If we extend that to all the views of the application, the complexity increases and the impact in maintainability of the application is huge.

In this paper we present an architectural design pattern to address this problem, as well as an analysis of its merits. The main idea behind the architectural pattern is that use cases take care of requesting the required entity providers from a unique element that is the persistence factory. Therefore use cases are created with the required entity provider(s) injected, allowing the other components of the architecture to be completely decoupled from the implementation of the persistence and simplifying the dependency injection process. The included code snippets compare our solution with most used industrial alternatives.