Root Fields

For the root types Query, Mutation or Subscription, you can define GraphQL fields using the following docblock tags:

• @gqlQueryField
• @gqlMutationField
• @gqlSubscriptionField

These tags may be placed before a:

• Static method
• Function declaration
• Arrow function declaration

tip

For defining fields on non-root types, see Fields.

Class-based root fields

If you want to group root fields that return or modify a specific type with that type's backing class, you can define them as part of that type's class using static methods:

TypeScript

/** @gqlType */
export class User {
  constructor(
    /** @gqlField */
    public name: string,
  ) {}

  /** @gqlQueryField */
  static me(): User {
    return new User("Elizabeth");
  }
}

Playground

GraphQL

type Query {
  me: User
}

type User {
  name: String
}

For more information about field resolves, see Resolver Signature.

Functional style root fields

If you prefer to avoid classes Grats also allows you to define root fields using named, exported functions. Function resolvers:

• Have a return type that matches the field type
• Are exported named functions where the function name is the desired field name

Extending Query:

const DB: any = {};

/** @gqlType */
type User = {
  /** @gqlField */
  name: string;
};

/** @gqlQueryField */
export function userById(id: string): User {
  return DB.getUserById(id);
}

Playground

Extending Mutation:

const DB: any = {};

/** @gqlType */
type User = {
  /** @gqlField */
  name: string;
};

/** @gqlMutationField */
export function deleteUser(id: string): boolean {
  return DB.deleteUser(id);
}

Playground

tip

Defining fields on these root types will cause the type to automatically be added to your schema. If you want to explicitly define one or more of these root types, for example to add a description, see Operation Types.

More field documentation

• Renaming for how to expose your field under a different name than your function/property/method
• Field Arguments for how to define arguments
• Descriptions for how to add descriptions to your fields
• Nullability for how to control the error handling and nullability of your field
• Deprecated for how to control the nullability of your field