pallavichaudhari / example-orders

GraphQL order management example

Example-Orders

A sample GraphQL order management endpoint using GraphQL for .NET. This is a more advanced version of the example I used in my course API Development in .NET with GraphQL

Running the sample

• If using Visual Studio, open Orders-GraphQL.sln build and run
• On Mac/Linux go the Server folder and run dotnet run -f netcoreapp2.0

Overview

This endpoint contains 2 core data types

• Orders - Orders that have been added to the system
• Customers - Customers for each order

API

Queries

orders

Retrieves a list of orders

example:

query getOrders {
  orders {
    id
    name
    description
    customer {
        name
    }
  }
}

orderById

Retrieves a specified order

Arguments

• orderId - The id of the order

example:

query getOrder {
  orderById(orderId: "FAEBD971-CBA5-4CED-8AD5-CC0B8D4B7827") {
    id
    name
    description
  }
}

customers

Retrieves all customers

example:

query getCustomers {
  customers {
    id
    name
  }
}

Mutations

createOrder

Creates an order

Arguments

• order - Information for the order to be created.

example:

mutation createOrder{
  createOrder(order:
    {
      name:"Glenn",
      description:"Test",
      customerId: 1,
      created: "03/16/2018"
    }
  ) 
  {
    id
    name
  }
}

startOrder

Starts the processing of an order. Can only be called if the order is in a CREATED state.

Arguments

• orderId - The id of the order

example starting an order

mutation startOrder {
  startOrder(orderId: "FAEBD971-CBA5-4CED-8AD5-CC0B8D4B7827") {
    id
    status
  }
}

completeOrder

Finishes the processing of an order. Can only be called if the order is in the PROCESSING state.

Arguments

• orderId - The id of the order

example completing an order

mutation completeOrder {
  completeOrder(orderId: "FAEBD971-CBA5-4CED-8AD5-CC0B8D4B7827") {
    id
    status
  }
}

cancelOrder

Cancels an order. Can only be called if the order is not in the COMPLETED or CANCELLED state.

Arguments

• orderId - The id of the order

example cancelling an order

mutation cancelOrder {
  cancelOrder(orderId: "FAEBD971-CBA5-4CED-8AD5-CC0B8D4B7827") {
    id
    status
  }
}

closeOrder

Closes an order. Can only be called if the order is in the COMPLETED state.

Arguments

• orderId - The id of the order

example closing an order

mutation closeOrder {
  closeOrder(orderId: "FAEBD971-CBA5-4CED-8AD5-CC0B8D4B7827") {
    id
    status
  }
}

Subscriptions

You can use subscriptions to get notified when an order is created. This relies on the awesome GraphQL Server project.

To test out subscriptions, you'll want to open two graphiql instances. One for subscribing, and the other for performing a mutation.

orderEvent

Notifies when order status changes.

Arguments

• statuses (optional) - An array of one or more statuses to receive notifications on

example subscribing to all order updates

subscription createdEvent {
  orderEvent {
    id
    name
    status
  }
}

example subscribing to order started events

subscription startedEvent {
  orderEvent ([PROCESSING]) {
    id
    name
    status
  }
}

Solution Structure

• Server - Contains the GraphQL Server / wires up GraphQL.NET middleware
• Orders - Contains models and the GraphQL Schema
  • Models - Contains the underlying models which drive the schema
  • Services - Contains data services for retrieving and updating models, as well as for notifications. Services are registered with the ASP.NET Core container allowing them to be injected wherever need.
  • Schema - Contains the GraphQL types, queries, mutuations and subscriptions.

License

Apache 2.0