DDD in Feakin

Feakin 的 DDD 语法参考了：https://contextmapper.org/docs/context-map/

Feakin 语法可以实现三个阶段：

  • 战略设计。语法：ContextMap、Context
  • 战术设计。语法：Aggregate、Entity、ValueObject
  • 实现。语法：impl

Quick Start

  1. 在线编辑器：https://online.feakin.com/
  2. 在 Template -> DDD Booking 使用 Feakin 语法设计
ContextMap TicketBooking {
    Reservation -> Cinema;
    Reservation -> Movie;
    Reservation -> User;
}

Context Reservation {
  Aggregate Reservation;
}

Context Cinema {
  Aggregate Cinema;
}

Aggregate Cinema {
  Entity Cinema, ScreeningRoom, Seat;
}

生成如下图所示的结果：

Basic Demo

详细过程：

  1. Fklang 编译器会转义 fkl 为 Dot 语法
  2. Feakin Render 渲染 Dot 语法

生成的 DOT 代码如下所示：

digraph TicketBooking2 {
  component=true;layout=fdp;
  node [shape=box style=filled];
  cluster_reservation -> cluster_cinema;
  cluster_reservation -> cluster_movie;
  cluster_reservation -> cluster_user;

  subgraph cluster_cinema {
    label="Cinema(Context)";

    subgraph cluster_aggregate_cinema {
      label="Cinema(Aggregate)";
      entity_Cinema [label="Cinema"];
      entity_ScreeningRoom [label="ScreeningRoom"];
      entity_Seat [label="Seat"];
    }
  }

  subgraph cluster_movie {
    label="Movie(Context)";
  }

  subgraph cluster_reservation {
    label="Reservation(Context)";

    subgraph cluster_aggregate_reservation {
      label="Reservation(Aggregate)";
    }
  }

  subgraph cluster_user {
    label="User(Context)";
  }
}

DDD Strategy

Step 1. Design Context Map

表示领域上下文图，用于描述系统的边界。

ContextMap TicketBooking {
  Reservation -> Cinema;
  Reservation -> Movie;
  Reservation -> User;
}

关系：

  • - - Undirected,
  • -> - PositiveDirected,
  • <- - NegativeDirected,
  • <-> - BiDirected,

Step 2. Context

表示限界上下文，以及对应的聚合间的关系。

Context Reservation {
  Aggregate Reservation;
}

DDD tactics

Step 1. DomainObject

表示领域对象，包括：聚合、实体、值对象。

Aggregate Reservation {
  Entity Ticket, Reservation;
}

Entity Reservation  {
  
}

附录：在线示例代码

ContextMap TicketBooking {
  Reservation -> Cinema;
  Reservation -> Movie;
  Reservation -> User;
}

Context Reservation {
  Aggregate Reservation;
}

Aggregate Reservation {
  Entity Ticket, Reservation;
}

Entity Reservation  {}

Entity Ticket  {}

Context Cinema {
  Aggregate Cinema;
}

Aggregate Cinema {
  Entity Cinema, ScreeningRoom, Seat;
}

Entity Cinema { }
Entity ScreeningRoom { }
Entity Seat { }

Context Movie {
  Aggregate Movie;
}

Aggregate Movie {
  Entity Movie, Actor, Publisher;
}

Entity Movie { }
Entity Actor { }
Entity Publisher { }

Context User {
  Aggregate User;
}

Aggregate User {
  Entity User;
}

Entity User {
}

Entity Payment {
}

ValueObject Price { }
ValueObject Notifications { }