Yo, i have store application with nestjs, i need validate mongo id, which is pass by query, the problem is that i also pass and search query. I write pipe which validate all values, and exclude this search query
@Injectable()
export class ValidationObjectId implements PipeTransform {
transform(value: UniqueId, metadata: ArgumentMetadata) {
if (
!Types.ObjectId.isValid(value) &&
metadata.data !== "searchString"
) {
throw new BadRequestException("Неверный параметр запроса");
}
return value;
}
}
But this code not reusable for other case. I want get some examples, how i can do this
The cleanest and most reusable approach would probably be to make use of the ValidationPipe with a Query-DTO-Class.
Take a look at the following example.
Inside the Controller you can pass a Pipe to the @Query()-Decorator.
You can use the ValidationPipe which already comes with Nest and makes use of the class-validator and class-transformer Packages.
You can create a DTO-Class for your Query-Parameters as done in the PostHelloQuery.dto.ts from my example.
import { IsBoolean, IsOptional } from "class-validator";
class PostHelloQueryDTO {
@IsOptional()
@IsBoolean()
public useExclamation?: boolean;
}
Here you define constraints for your Data using decorators from class-validator. For a list of all decorators, please refer to https://github.com/typestack/class-validator#validation-decorators .
If none of the validators fit your needs you can also create your own Decorator as shown here.
In my example, the useExclamantion-Query Param is an optional boolean.
Note that incoming query parameters are parsed as strings.
The conversion is done using the enableInplicitConversion-Option as seen in the Controller:
@Query(new ValidationPipe({
transform: true,
transformOptions: {enableImplicitConversion: true},
forbidNonWhitelisted: true
}) query: PostHelloQueryDTO
For more information about using ValidationPipe with class-validator, you can take a look at the NestJS Documentation:
https://docs.nestjs.com/techniques/validation
For your specific Use-Case (Validating MongoDB IDs), I have found an open Issue with an Example Implementation for a @IsMongoDB-Decorator:
https://github.com/typestack/class-validator/issues/630#issuecomment-645638436