CODEWITHSUNDEEP
graphqlgraphql-js
Guy
Guy

Reputation: 23

Graphql type resolver by id

I'm trying to get familiar with Graphql by building a server with the following schema:

type Game
{
    id: ID!
    players: [Player!]!
    winner: Player
    ...
}

type Player {
    id: ID!
    game: Game!
    ...
}

type Query {
    getGame(id: ID!): Game
    getPlayer(id: ID!): Player
}

And map to the following data:

const games = {
    1: {
        id: 1,
        players: [2, 3],
        winner: undefined
    }
};
const players = {
    2: {
        id: 2,
        game: 1
    },
    3: {
        id: 3,
        game: 1
    },
};

While writing the resolvers, I noticed a lot of boilerplate code - I had to write conceptually the same field resolver for every object member which holds a foreign key.

const typedefs = {
    Query: {
        getGame: (_, {id}) => games[id],
        getPlayer: (_, {id}) => players[id]
    },
    Game: {
        winner: (game) => players[game.winner],
        players: (game) => game.players.map(id => players[id])
    },
    Player: {
        game: (player) => games[player.id]
    }
}

Is there a way to create a type resolver by ID? for example, a Player field or query would always be resolved by (id) => players[id], and a game field or query would always be resolved by (id) => games[id].

I saw that this is achievable using AWS-Amplify's @model directive, but I'm wondering if there is a more standard way I'm missing rather than implementing my own directive.

Is this a feature of any current Graphql implementation? I couldn't find anything that resembles it in apollo-graphql's documentation (or in graphql-js's).

Thanks.

Upvotes: 2

Views: 879

Answers (1)

Herku
Herku

Reputation: 7666

There is no way of changing the default resolver. Apollo-GraphQL just passes the resolver map to graphql-tools and graphql-tools uses graphql-js. graphql-js implements the default resolver here and uses it here.

Maybe you could try using ES2015 Proxy to provide a default implementation for resolvers in the object instead. But even if you override your default resolver, you break all the places where you used the actual default resolver.

Upvotes: 0

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