Apollo GraphQL - Is it possible to do the same query requesting different fields?

Question

I am using apollo-android and I want to know if it is possible to do the following approach:

I have defined a query called locations in the schema.json of my server. It is defined like this:

type locations {
  continents: [Continent!],
  countries: [Country!],
  usaStates: [UsaState!]
}

Trying this query in the Playground works perfectly and it returns the continents, countries and usaStates. This is the query I define in the Playground:

query getLocations {
  locations {
    continents {
      name
      code
    }
    countries {
      name
      code
    }
    usaStates {
      code
      name
    }
  }
}

And of course, if I only request que continents, it only returns the continents:

query getLocations {
  locations {
    continents {
      name
      code
    }
}

My question is if it's possible to do the same in the client part. When I define the query in the api.graphql file of my Android project, I do it like this:

query getLocations {
  locations {
    continents {
      name
      code
    }
    countries {
      code
      name
    }
    usaStates {
      code
      name
    }
  }
}

And then, when I call it in the code, the result contains the continents, countries and usaStates:

GetLocationsQuery builder = GetLocationsQuery.builder().build();

api.query(builder)
    .enqueue(new ApolloCall.Callback<GetLocationsQuery.Data>() {
            @Override
            public void onResponse(@NotNull com.apollographql.apollo.api.Response<GetLocationsQuery.Data> response) {
                apiListener.onFinish(response);
            }

            @Override
            public void onFailure(@NotNull ApolloException e) {
                Log.v("APOLLO", e.toString());
                apiListener.onError(e);
            }
        });

There is a way to do the same call but defining that I only want the continents instead continents, countries and usaStates?

Thank you in advance!

Answer 1

The specification says:

The core GraphQL specification includes exactly two directives, which must be supported by any spec-compliant GraphQL server implementation:

• @include (if: Boolean) Only include this field in the result if the argument is true.
• @skip (if: Boolean) Skip this field if the argument is true.

api.graphql with skip directive:

query getLocations($continentsOnly: Boolean) {
  locations {
    continents {
      name
      code
    }
    countries @skip(if: $continentsOnly) {
      code
      name
    }
    usaStates @skip(if: $continentsOnly) {
      code
      name
    }
  }
}

Obviously, you will need to specify the value of continentsOnly