Apollo GraphQL Server中标量的指令

如何解决Apollo GraphQL Server中标量的指令

我在架构中将Date定义为标量。

是否只有一种方法可以定义有关法律价值的规则？

我可能会在FIELD_DEFINITION上定义一个指令，并将其应用于这种类型的每个字段。但是，我想做一次。有可能吗？

这是我的代码。 CitizenshipCode实际上是一个字符串，限于值“ us”，“ uk”，“ de”等。我想以集中方式实现验证，而不是向该类型的每个字段添加指令：

scalar CitizenshipCode    # is it possible to implement the validation here?


type Client {
  id: ID!
  name: String
  citizenship: CitizenshipCode   #  instead of here...
  # other atts
}

type User {
  id: ID!
  email: String
  citizenship: CitizenshipCode   #  ... and here
  # other atts
}

解决方法

也许您可以在代码中使用枚举类型或使用自定义架构：

const { ApolloServer,gql,SchemaDirectiveVisitor } = require('apollo-server');
const { GraphQLScalarType,Kind } = require('graphql');

const validCountryCodes = [ "US","UK","DE"];

const citizenshipCodeScalar = new GraphQLScalarType({
    name: 'CitizenshipCode',description: 'Allowed citizen ship codes',serialize(value) {
        return validCountryCodes.includes(value) ? value : "INVALID COUNTRY";
    },parseValue(value) {
        return validCountryCodes.includes(value) ? value : null;
    },parseLiteral(ast) {
        return ast.kind === Kind.STRING ? ast.value : null;
    }
});

const typeDefs = gql `
  scalar CitizenshipCode

  type Client {
    id: ID
    name: String
    citizenship: CitizenshipCode
  }

  type User {
    id: Int
    email: String
    citizenship: CitizenshipCode
  }

  type Query {
      clients: [Client]
      users: [User]
  }
`;

const resolvers = {
    Query: {
        clients: () => clients,users: () => users
    },CitizenshipCode: citizenshipCodeScalar
};

const client = [{
        id: 'client1',name: 'The Awakening',citizenship: 'US'
    },{
        id: 'client2',title: 'City of Glass',citizenship: 'CA',},];

const users = [{
        id: 1,email: '[e-mail]',citizenship: 'UK',{
        id: 2,email: '[e-mail]',citizenship: 'DE',];

const server = new ApolloServer({
    typeDefs,resolvers
});