Architecture

Data Objects

Different types of data flow between different parts of the application. Your application may use

• Raw data - data obtained in its raw form from a database, file, service, etcetera. The data source formats it into an object to be passed back to the repository
• Entities - data obtained from data sources
• Data Transfer Objects (DTOs) - data abstracted/restricted before being passed out of the Data Layer
• State - data prepared for use in the user interface

A typical flow of data might look like

Without Domain LayerWith Domain Layer

flowchart RL
    subgraph User Interface Layer
    vm[View Model] -->|State| ui[User Interface]
    end
    repo -->|DTO| vm
    db[(Database)] -->|raw| ds
    subgraph Data Layer
    ds[Data Source] -->|Entity| repo[Repository]
    end

flowchart RL
    subgraph User Interface Layer
    vm[View Model] -->|State| ui[User Interface]
    end
    Data
    data -->|DTO| vm
    repo -->|DTO| data
    db[(Database)] -->|raw| ds
    subgraph Domain Layer
    direction TB
    data[Data]
    uc[Use Case]
    end
    subgraph Data Layer
    ds[Data Source] -->|Entity| repo[Repository]
    end