根据用户输入动态地将国家代码传递给@IsPhoneNumber()

Question

我有一个使用 class 验证器的 DTO，如下所示。

export class RandomlyNamedDto {
  @IsRequired()
  @Max(3)
  @Min(2)
  countryCode: string;
  
  @IsPhoneNumber()
  phone: string;
}

我想根据用户发送的国家代码将国家代码传递给@IsPhoneNumber() 。 例如，如果 countryCode = 'UK' 验证器将如下所示。

IsPhoneNumber('UK')

Answer 1

您可以通过创建自定义装饰器并将其注册到类验证器库来实现此目的。 下面的代码改编自另一个堆栈溢出答案以符合您的标准：

import {
  ValidationOptions,
  registerDecorator,
  ValidationArguments,
  buildMessage,
  IsDefined,
  validate,
  isPhoneNumber,
  MaxLength,
  MinLength,
} from "class-validator";

export function IsPhoneNumberForRegion(
  property: string,
  validationOptions?: ValidationOptions
) {
  return function (object: Object, propertyName: string) {
      registerDecorator({
        name: "isPhoneNumberForRegion",
        target: object.constructor,
        propertyName: propertyName,
        constraints: [property],
        options: validationOptions,
        validator: {
            validate(value: any, args: ValidationArguments) {
              // the property name that holds the country code
              const [countryCodeField] = args.constraints;

              // the value of the country code on the target object
              const countryCode = (args.object as any)[countryCodeField];

              // validate phone number for specified region
              return isPhoneNumber(value, countryCode);
            },
            // specify custom error message
            defaultMessage: buildMessage(
            (eachPrefix) =>
              `${eachPrefix} $property must be a valid phone number in the specified region`,
            validationOptions
            ),
        },
    });
  };
}

class ExampleUsage {
  @IsDefined()
  @MaxLength(3)
  @MinLength(2)
  countryCode: string;

  @IsPhoneNumberForRegion("countryCode")
  phone: string;

  constructor(countryCode: string, phone: string) {
    this.phone = phone;
    this.countryCode = countryCode;
  }
}

(async () => {
  const exampleGood = new ExampleUsage("US", "(201)-867-5309");
  const validationPasses = await validate(exampleGood);
  console.log(validationPasses);

  const exampleErrors = new ExampleUsage("US", "not a phone number");
  const validationWithErrors = await validate(exampleErrors);
  console.log(validationWithErrors);
})();