What is the role of the Presenter in Clean Architecture?

In Clean Architecture, the role of the Presenter is to act as an intermediary between the use case interactor and the view. The Presenter is responsible for transforming the output data from the use case interactor into a format that is suitable for the view to display. This transformation typically involves converting the raw data into a ViewModel, which is a data structure that the view can easily consume and render.

Here are the key responsibilities of the Presenter in Clean Architecture:

1. Data Transformation: The Presenter takes the output data from the use case interactor and formats it into a ViewModel. This ViewModel contains all the necessary information in a format that the view can directly use, such as stringified dates, labels, and other UI-specific data[6][8].

2. Separation of Concerns: By handling the transformation of data, the Presenter helps to maintain a clear separation of concerns. The use case interactor focuses on business logic and data processing, while the Presenter focuses on preparing data for presentation[1][3].

3. Decoupling: The Presenter decouples the business logic from the UI logic. This decoupling ensures that changes in the business logic do not directly affect the UI and vice versa. It also makes the system more testable, as the Presenter can be tested independently of the view and the use case interactor[10][11].

4. Interface Adapters: In Clean Architecture, the Presenter serves as an interface adapter. It adapts the data from the use case interactor to the format required by the view, ensuring that the view remains simple and focused on rendering the data[4][7].

5. Handling Multiple Views: When an application has multiple views (e.g., CLI and Web), each view might require different data formats. The Presenter can handle these differences by creating different ViewModels for each view, ensuring that the use case interactor remains agnostic of the specific presentation requirements[4]...