Pagination Support with Querydsl and Query By Example

[rstoyanchev]

A specific task under Pagination and Sorting #103 is to enable such support for the Querydsl and Query By Example data integrations. This involves the following tasks:

• Update QuerydslDataFetcher and QueryByExampleDataFetcher to support pagination.
• Facilitate adapting Spring Data types to GraphQL schema types for pagination (e.g. relay spec). We need the same for @SchemaMapping methods too, so this could be some shared.
• Update auto-registration.

[dja557]

@rstoyanchev Hi! This framework is great. I'm having trouble setting up sorting via the QueryDSL support here. Can you provide an example of how this is supposed to work? I followed the documentation here but was unsuccessful. Here is my example:

Repository

@GraphQlRepository
public interface CustWebTranRepository extends PagingAndSortingRepository<CustWebTran,CustWebTranPK>,
        QuerydslPredicateExecutor<CustWebTran> {
}

Schema

type Query {
    transaction(customerId: String
        ...
        first:Int
        after:String
        last:Int
        before:String,
        sort: [String],
        direction: Direction
    ): CustWebTranConnection
}
type CustWebTranConnection {
    edges: [CustWebTranEdge]!
    pageInfo: PageInfo!
}
type CustWebTranEdge {
    node: CustWebTran!
    cursor: String!
}

SortStrategy Bean

@Bean
public SortStrategy sortStrategy() {
    return new AbstractSortStrategy() {
        @Override
        protected List<String> getProperties(DataFetchingEnvironment environment) {
            return environment.getArgument("sort");
        }

        @Override
        protected Sort.Direction getDirection(DataFetchingEnvironment environment) {
            return Sort.Direction.fromOptionalString(environment.getArgument("direction")).orElse(null);
        }
    };
}