GraphlQL implementation for rata.digitraffic.fi

Build and test:

$ mvn clean test

Run:

$ mvn spring-boot:run

GraphiQL, an in-browser IDE for exploring GraphQL, is embedded through graphiql-spring-boot-starter and available at http://localhost:8081/graphiql.

Sample query to be run:

{
  train(trainNumber: 51, departureDate: "2020-06-29") {
    cancelled
    commuterLineid
    deleted
    departureDate
    runningCurrently
    timetableAcceptanceDate
    timetableType
    trainNumber
    version
    operator {
      name
    }
    timeTableRows {
      scheduledTime
      actualTime
      station {
        shortCode
      }
      causes {
        categoryCode {
          code
        }
      }
    }
  }
}

Architecture:

• config
  • Spring Boot config, GraphQL instruments etc
• entities
  • Classes modeling rows returned from database
• links
  • Logic implementing "links" in GraphQL graph
• queries
  • Logic implementing GraphQL queries
• querydsl
  • Logic for creating querydsl queries
• to
  • Logic for converting entities to GraphQL objects (=TOs)

How to add GraphlQL stuff

Query

...

Link

Basic workflow

1. Modify schema.graphqls to include your new data
2. Create Hibernate entity
3. Generate QueryDSL and GraphQL DTOs with mvn compile
4. Add Hibernate fields to AllFields
5. Create Hibernate -> GraphQL DTO converter (example TrackSectionTOConverter)
6. Create GraphQL link (example TrainTrackingMessageToTrackSectionLink)
7. Done

See 0271e6a9926dfb1be99f08632f7f35f5ba654ffe for an example

Updating schema.svg

The schema visualization has been generated with http://nathanrandal.com/graphql-visualizer/ using the below introspection query:

query IntrospectionQuery {
    __schema {
        queryType { name }
        mutationType { name }
        subscriptionType { name }
        types {
            ...FullType
        }
        directives {
            name
            description
            args {
                ...InputValue
            }
        }
    }
}

fragment FullType on __Type {
    kind
    name
    description
    fields(includeDeprecated: true) {
        name
        description
        args {
            ...InputValue
        }
        type {
            ...TypeRef
        }
        isDeprecated
        deprecationReason
    }
    inputFields {
        ...InputValue
    }
    interfaces {
        ...TypeRef
    }
    enumValues(includeDeprecated: true) {
        name
        description
        isDeprecated
        deprecationReason
    }
    possibleTypes {
        ...TypeRef
    }
}

fragment InputValue on __InputValue {
    name
    description
    type { ...TypeRef }
    defaultValue
}

fragment TypeRef on __Type {
    kind
    name
    ofType {
        kind
        name
        ofType {
            kind
            name
            ofType {
                kind
                name
            }
        }
    }
}