如何为MongoDB的collection.find()函数中找到的MongoDB排序属性实现GraphQL标量? [英] How to implement GraphQL Scalar for MongoDB sort property found in collection.find() function of MongoDB's?

问题描述

我正在尝试使用 type-graphql 创建一个参数类型，以通过GraphQL查询接受参数.我在说的 sort 是

I'm trying to create an argument type using type-graphql to accept arguments through the GraphQL query. The sort I'm talking about is a property of the options found on MongoDB's native NodeJS driver documentation.

@ArgsType()
export class FindAllArgs implements FindOneOptions {
    @Field(type => Int, { defaultValue: 0, description: 'Sets the limit of documents returned in the query.' })
    @Min(0)
    limit?: number;

    // This is where the custom sort would go about.
    @Field(type => SortScalar)
    sort?: sortScalar;

    @Field(type => Int, { defaultValue: 0, description: 'Set to skip N documents ahead in your query (useful for pagination).' })
    @Min(0)
    skip?: number;
}

如您所见，简单类型很好，但是当涉及到排序对象之类的东西时，我不确定该如何进行下去.

As you can see, simple types are fine, but when it comes to something like the sort object, I'm not sure how to go on about it.

NestJS 实现日期标量:

import { Scalar, CustomScalar } from '@nestjs/graphql';
import { Kind, ValueNode } from 'graphql';

@Scalar('Date', type => Date)
export class DateScalar implements CustomScalar<number, Date> {
  description = 'Date custom scalar type';

  parseValue(value: number): Date {
    return new Date(value); // value from the client
  }

  serialize(value: Date): number {
    return value.getTime(); // value sent to the client
  }

  parseLiteral(ast: ValueNode): Date {
    if (ast.kind === Kind.INT) {
      return new Date(ast.value);
    }
    return null;
  }
}

即使在示例中，它也使用returnTypeFunction @Scalar('Date'，type => Date).我应该用 Date 替换什么?我要为 parseValue ， serialize 和 parseLiteral 输入什么?

Even in the example, it uses a returnTypeFunction @Scalar('Date', type => Date). What am I supposed to replace Date with? What do I put in for parseValue, serialize, and parseLiteral?

推荐答案

您可以只使用 @InputType 将对象嵌套在args中-您不需要标量，它们仅用于可序列化的内容，例如时间戳->数字，mongo id-> ObjectId实例等.

You can just use @InputType to nest objects in args - you don't need scalars for that, they are designed only for serializable things like timestamp -> number, mongo id -> ObjectId instance, etc.

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