Generate Relay Connection (Version: 3.0.0)

[vinaybedre]

Issue Description

I am using GraphQL Java Kickstarter's relay function. See https://www.graphql-java-kickstart.com/tools/relay/
I have below schema:

type Query {
    users(first: Int, after: String): UserConnection @connection(for: "User")
    organizations(first: Int, after: String): OrganizationConnection @connection(for: "Organization")
}

type User {
    id: ID!
    name: String
}

type Organization {
    id: ID!
}

Steps to Reproduce

In a Java project, under gradle, setup basic graphql-java-codegen config, copy the above schema to resources as .graphqls file, run Gradle task graphqlCodegen

Expected Result

Generate model classes UserConnection and OrganizationConnection
The associated query should have signature

public Connection<User> users(int first, String after, DataFetchingEnvironment env);

Actual Result

The model classes are missing.

UserConnection users(Integer first, String after, graphql.schema.DataFetchingEnvironment env) throws Exception;

Your Environment and Setup

• graphql-java-codegen: 3.0.0
• Build tool: Gradle
• Java tool: openjdk version "14.0.1"

[kobylynskyi]

@vinaybedre thanks for reporting this!

[kobylynskyi]

Just to clarify:
If directive @connection(for: TypeName) is present for the Query/Mutation/Subscription, then ignore the actual return type of the operation and use the value of directive argument for wrapped into graphql.relay.Connection:
graphql.relay.Connection<TypeName>
@vinaybedre Does it sound right to you?

[vinaybedre]

@kobylynskyi Let me put in this way, when we have @connection(for: TypeName, for a Query/Mutation/Subscription, then we shall treat the spec to be like this

type Query {
    users(first: Int, after: String): UserConnection
    organizations(first: Int, after: String): OrganizationConnection
}

type UserConnection {
    edges: [UserEdge]
    pageInfo: PageInfo
}

type UserEdge {
    cursor: String
    node: User
}

type PageInfo {
  hasPreviousPage: Boolean!
  hasNextPage: Boolean!
}

type User {
    id: ID!
    name: String
}

type OrganizationConnection {
    edges: [OrganizationEdge]
    pageInfo: PageInfo
}

type OrganizationEdge {
    cursor: String
    node: Organization
}

type Organization {
    id: ID!
}

[kobylynskyi]

@kobylynskyi Let me put in this way, when we have @connection(for: TypeName, for a Query/Mutation/Subscription, then we shall treat the spec to be like this

If we treat the schema the way you mentioned, then backend will generate the following interface method (which is not what you want based on the description of the ticket):

public interface UsersQueryResolver {
    UserConnection users(Integer first, String after) throws Exception;
}

Instead, you want to have:

public interface UsersQueryResolver {
    graphql.relay.Connection<User> users(Integer first, String after) throws Exception;
}

@vinaybedre does it sound right to you?

[vinaybedre]

@kobylynskyi Sorry for the confusion.
I want codegen to generate interface like below

public interface UsersQueryResolver {
    UserConnection users(Integer first, String after) throws Exception;
}

along with all the depending models. Nothing to do with graphql.relay.Connection<User>

[kobylynskyi]

@vinaybedre on the link you provided it is stated that the resolver method should have return type Connection<User>:

class QueryResolver implements GraphQLQueryResolver {

  public Connection<User> users(int first, String after, DataFetchingEnvironment env) {
    return new SimpleListConnection<>(Collections.singletonList(new User(1L, "Luke"))).get(env);
  }
}

Can you please explain why do you want to have UserConnection users(...)?
Thanks

[kobylynskyi]

@vinaybedre can you please clarify on the question above?

[vinaybedre]

@kobylynskyi
Sorry for messing things up. I was working on to get a custom relay up to working and I mistyped.
The point of this bug ticket/issue should be to adhere to official relay specification and hence, the interface should return Connection<User>
More info on why relay should be used can be viewed here https://www.howtographql.com/react-relay/8-pagination/