Configure specific GraphQL schema files

[bjoernmayer]

Heyho,

it seems like there is currently no way to specify schema files by their filename. Instead it is only possible to configure directories.

From GraphqlProperties.java:

private String[] appendSlashIfNecessary(String[] locations) {
            return Arrays.stream(locations)
                .map((location) -> location.endsWith("/") ? location : location + "/")
                .toArray(String[]::new);
        }

Hence this is impossible:

spring.graphql.schema:
    locations:
        # Subgraph's schema
        - classpath:schema/schema.graphqls
        # Federation-specific directives (shared across subgraphs)
        - classpath:schema/federation.graphqls
        # Common types (shared across subgraphs)
        - classpath:schema/Accommodation.graphqls
        - classpath:schema/AccommodationDeal.graphqls

I encountered this obstacle when trying to migrate from DGS to Spring GQL

[bclozel]

Hello @bjoernmayer

Yes that's correct, those are meant to be locations, not fully resolved resources. I'm not sure I understand the use case though. Why point directly to resources and not locations? Are there schema resources in the same location that are not meant to be used? Why?

[bjoernmayer]

Hi @bclozel, thank you for looking into this.

The main reason is Federation.

We are working with subgraphs in a Mono Repository. We have all of our shared types in a shared library. Each subgraph then picks only the types, that it needs and should expose in its schema.

[bclozel]

Spring for GraphQL provides a org.springframework.graphql.execution.GraphQlSource.SchemaResourceBuilder#schemaResources that lets you configure specific schema files.

You can already declare specific resources in your application by contributing a GraphQlSourceBuilderCustomizer bean to your application and add resources manually.

I'll move this issue to Spring Boot to consider a separate configuration property that would let you set additional schema resources on top of scanned ones.