Date and Json in type definition for graphql

Mohamed Taboubi picture Mohamed Taboubi · Apr 6, 2018 · Viewed 27.4k times · Source

Is it possible to have a define a field as Date or JSON in my graphql schema ?

type Individual {
    id: Int
    name: String
    birthDate: Date
    token: JSON
}

actually the server is returning me an error saying :

Type "Date" not found in document.
at ASTDefinitionBuilder._resolveType (****node_modules\graphql\utilities\buildASTSchema.js:134:11)

And same error for JSON...

Any idea ?

Answer

Andreas Köberle picture Andreas Köberle · Apr 6, 2018

Have a look at custom scalars: https://www.apollographql.com/docs/graphql-tools/scalars.html

create a new scalar in your schema:

scalar Date

type MyType {
   created: Date
}

and create a new resolver:

import { GraphQLScalarType } from 'graphql';
import { Kind } from 'graphql/language';

const resolverMap = {
  Date: new GraphQLScalarType({
    name: 'Date',
    description: 'Date custom scalar type',
    parseValue(value) {
      return new Date(value); // value from the client
    },
    serialize(value) {
      return value.getTime(); // value sent to the client
    },
    parseLiteral(ast) {
      if (ast.kind === Kind.INT) {
        return parseInt(ast.value, 10); // ast value is always in string format
      }
      return null;
    },
  }),