假设您有一个将数据发布到API服务器的表单. API服务器验证输入并返回
JSON对象.如果输入无效,则返回如下所示的错误对象.
{errors: {field1: "is required"}}
使用GraphQL时,我们如何处理和提供这些错误？数据验证的实现方式和位置(应该是GraphQL的一部分,还是应该在每个解析函数内)？
解决方法
通过解析方法中的验证逻辑,可以完全控制生成的用户错误.这是一个例子：
// data/mutations/createUser.js
import {
GraphQLObjectType as ObjectType,GraphQLNonNull as NonNull,GraphQLList as List,GraphQLString as StringType
} from 'graphql';
import validator from 'validator';
import UserType from '../types/UserType';
export default {
type: new ObjectType({
name: 'CreateUserResult',fields: {
user: { type: UserType },errors: { type: new NonNull(new List(StringType)) }
}
}),args: {
email: { type: new NonNull(StringType) },password: { type: new NonNull(StringType) }
},resolve(_,{ email,password }) {
let user = null;
let errors = [];
if (validator.isNull(email)) {
errors.push(...['email','The email filed must not be empty.']);
} else if (!validator.isLength(email,{ max: 100})) {
errors.push(...['email','The email must be at a max 100 characters long.']);
}
// etc.
return { user,errors };
}
};
查看我的博客文章这个主题 – Validation and User Errors in GraphQL Mutations
或者,创建类型UserErrorType {key：String !,message：String！ }当您编译要返回给调用者的用户错误列表时,可以使用而不是纯字符串.
GraphQL查询
mutation {
createUser(email: "hello@tarkus.me",password: "Passw0rd") {
user { id,email },errors { key,message }
}
}
查询响应
{
data: {
user: null,errors: [
{ key: '',message: 'Failed to create a new user account.' },{ key: 'email',message: 'User with this email already exists.' }
]
}
}
