如何设置DTO嵌套Js的默认值

Question

import { IsString, IsNumber, IsOptional, IsUUID, Min, Max } from 'class-validator';
import { Transform } from 'class-transformer';
export class QueryCollateralTypeDto {
  @Transform(({ value }) => parseInt(value))
  @IsNumber()
  @IsOptional()
  page: number;
  @Transform(({ value }) => parseInt(value))
  @IsNumber()
  @IsOptional()
  limit: number;
  @IsString()
  @IsOptional()
  select: string;
}

我想设置页面和限制的默认整数值以及选择的字符串值(例如页面值为整数1，限制值为整数10，选择值为"field1，field2，…"(

Answer 1

Okey我找到了一个解决方案，我想你只是在DTO 中初始化变量

import { IsString, IsNumber, IsOptional, IsUUID, Min, Max } from 'class-validator';
import { Transform } from 'class-transformer';
export class QueryCollateralTypeDto {
  @Transform(({ value }) => parseInt(value))
  @IsNumber()
  @IsOptional()
  page: number = 1;
  @Transform(({ value }) => parseInt(value))
  @IsNumber()
  @IsOptional()
  limit: number = 10;
  @IsString()
  @IsOptional()
  select: string = 'name,description';
}

Answer 2

您可以在服务和使用数据的函数中设置默认值，如下图所示。如果不向函数传递任何值，则会设置默认值。

exampleFunction(data: QueryCollateralTypeDto) {
    const { page = 1, limit = 10, select = 'field1' } = data;
    ...
}

Answer 3

您必须使用ValidationPipe为控制器或方法添加选项transform-on-true(https://docs.nestjs.com/techniques/validation)

//at the controller level:
@Controller('some_controller')
@UsePipes(new ValidationPipe({ transform: true}))
export class SomeController {
  constructor() {}
  //or at the method level
  @Post()
  @UsePipes(new ValidationPipe({ transform: true}))
  create(
    @Body() someDto: SomeDto,
  ): Promise<someEntity> {
    return this.service.create(someDto);
  }