How to return complex object as scalar type in GraphQL?

Question

Let's imagine we have GraphQL API that can return an object Entity with Id and Name properties and I requested Name only:

query {
    entities {
        name
    }
}

And it returns

{
    "data": {
        "entities": [
        {
            "name": "Name1"
        },
        {
            "name": "Name2"
        }
        ]
    }
}

But what if I want to have only the name of entities as a scalar type? In other words, I want to have something like:

{
    "data": {
        "entities": [
            "Name1",
            "Name2"
        ]
    }
}

Is it possible to have such result without changes on the GraphQL API side? Aliases, Fragments, etc. GraphQL has a lot of built-in query capabilities, but none of the known me can return complex objects as scalar type.

You can create an enum type with values Name1, Name2.. but you will need server side changes to let graphql know how to process the enum — Mat G
Thanks, but I have few clients with different needs, trying to find way without changes, GraphQL is flex for that, but not in all cases :-( — DevForRest

fortunee fortunee · Accepted Answer · 2021-03-25T21:38:38

what you're asking for is almost impossible if you don't want to change the type definition for Entities.

This: 👇🏽

Entity: id: int! name: String
entities(): [Entity]

returns an array of objects with keys name and id.

To achieve what you're asking you either change Entity to be just a string or have your client reduce that object to an array of just Entity names when they receive it.

They could do something like this:

const data = {
  entities: [
    {
      name: 'Name1',
    },
    {
      name: 'Name2',
    },
  ],
};

const entityNames = data.entities.reduce(
  (acc, curr) => [...acc, curr.name],
  []
);

console.log(entityNames);

How to return complex object as scalar type in GraphQL?

1 Answers