EC platform — staged tutorial

The language taught one construct at a time, in seven self-contained files. Shown here at stage 3 (domain / usecase / resource); the rest are in the repository.

View the source on GitHub

System view

Source

ec-platform/03-domains.krs

// Demonstrates: domain, usecase, resource — full drill-down hierarchy
// Drill into ECommerce to see its internal domain structure.

system ECPlatform {
  label "EC Platform"

  user Customer [human] {
    label "Customer"
    role "End users who purchase products"
  }

  service ECommerce {
    label "EC Site"

    domain Order {
      label "Orders"
      description "Accept, manage, and cancel orders"

      usecase PlaceOrder {
        label "Place an order"
        resource OrderTable {
          label "Order table"
          operations create, read
        }
        resource InventoryAPI {
          label "Inventory API"
          operations read
        }
      }

      usecase CancelOrder {
        label "Cancel an order"
        resource OrderTable {
          label "Order table"
          operations read, update
        }
      }

      usecase QueryOrder {
        label "Query order status"
        resource OrderTable {
          label "Order table"
          operations read
        }
      }
    }

    domain Catalog {
      label "Product Catalog"
      description "Manage and search product information"

      usecase SearchProducts {
        label "Search products"
        resource ProductTable {
          label "Product table"
          operations read
        }
      }

      usecase UpdateProduct {
        label "Update product information"
        resource ProductTable {
          label "Product table"
          operations read, update
        }
        resource ImageStorage {
          label "Image storage"
          operations create, update, delete
        }
      }
    }
  }

  service Payment {
    label "Payment Service"

    domain Billing {
      label "Billing"

      usecase Charge {
        label "Execute payment"
        resource PaymentGateway {
          label "Payment gateway"
        }
        resource TransactionLog {
          label "Transaction log"
        }
      }

      usecase Refund {
        label "Issue a refund"
        resource PaymentGateway {
          label "Payment gateway"
        }
      }
    }
  }

  service Inventory {
    label "Inventory"

    domain Stock {
      label "Stock"

      usecase CheckStock {
        label "Check stock"
        resource StockTable {
          label "Stock table"
        }
      }

      usecase ReserveStock {
        label "Reserve stock"
        resource StockTable {
          label "Stock table"
        }
      }
    }
  }

  Customer  ->  ECommerce "Purchase products"
  ECommerce ->  Payment   "Process payment"
  ECommerce ->  Inventory "Check inventory"
}