Typescript 带有服务层的NESTJS验证管道和CustomValidatorDecorator

你好，我最近刚接触NESTJS，我需要帮助解决这个问题。问题在于，我需要在验证管道上访问请求的令牌以调用另一个api（使用相同的令牌），并使用HttpModule检查发送的id是否有效

验证管道（来自nestjs文档的样本）：

这样做的目的是，在DTO上，我将decorators放入验证，然后他自动调用api来检查语言id是否存在

  @ApiModelProperty()
  @IsLanguageValid({}, { message: 'the language id sent is not valid'})
  @IsNumber({}, { message: 'the id should be a number' })
  language_id: number;

import { registerDecorator, ValidationOptions, ValidationArguments } from 'class-validator';

export function IsLanguageValid(property: string, validationOptions?: ValidationOptions) {
  return function(object: Object, propertyName: string) {
    registerDecorator({
      name: 'isLanguageValid',
      target: object.constructor,
      propertyName: propertyName,
      constraints: [property],
      options: validationOptions,
      validator: {
        validate(value: any, args: ValidationArguments) {
          const [relatedPropertyName] = args.constraints;
          const relatedValue = (args.object as any)[relatedPropertyName];

          // WHERE HOW CAN I ACCESS TO A SERVICE AND TOKEN OF THE REQUEST
          this.httpModule.get('url to other api', { headers: { authrorization : TOKEN }})
        },
      },
    });
  };
}

  @ApiModelProperty()
  @IsLanguageValid({}, { message: 'the language id sent is not valid'})
  @IsNumber({}, { message: 'the id should be a number' })
  language_id: number;