DTO only fields

[j-vitali]

HI, very nice library... can I pass only the fileds from my quuery DTO? I don't want user to filter everything...

[lucasrochagit]

Hi @j-vitali, thanks for using this library.

Unfortunately, it is not yet possible to use only fields in your DTO query. But this feature may be available in a future version of the library.

However, you can create a custom decorator to set the other values that you do not want to use to undefined.

[j-vitali]

@lucasrochagit is it a good idea??

import { IsNumber, IsOptional, IsString } from 'class-validator';
import { MongoQueryModel } from 'nest-mongo-query-parser';

export class QueryLanguageDTO extends MongoQueryModel {

  @IsOptional()
  @IsString()
  value: string;
}

[lucasrochagit]

@lucasrochagit is it a good idea??

import { IsNumber, IsOptional, IsString } from 'class-validator';
import { MongoQueryModel } from 'nest-mongo-query-parser';

export class QueryLanguageDTO extends MongoQueryModel {

  @IsOptional()
  @IsString()
  value: string;
}

@j-vitali Currently the library does not support query parameter validations. But this feature may be added in future versions of the library.

[j-vitali]

@lucasrochagit is it a good idea??

import { IsNumber, IsOptional, IsString } from 'class-validator';
import { MongoQueryModel } from 'nest-mongo-query-parser';

export class QueryLanguageDTO extends MongoQueryModel {

  @IsOptional()
  @IsString()
  value: string;
}

@j-vitali Currently the library does not support query parameter validations. But this feature may be added in future versions of the library.

Hi could you give me and example? Maybe another solution will be; create a DTO with all wanted fields, then add pagination also... and then pass it to service that wil be an injectable function and will transform passed DTO to mongoquerymodel. (2nd usage of readme)

What do you think?

[lucasrochagit]

@j-vitali I'm really sorry, I completely forgot about the second usage.

Yes, you can validate some fields from query with the second usage and class validator. You can do something as this example:

the service:

// user.service.ts
import { Injectable } from "@nestjs/common";
import { MongoQueryModel, MongoQueryParser } from "nest-mongo-query-parser";

@Injectable()
export class UserService {
  @MongoQueryParser()
  find(query: MongoQueryModel) {
    return query;
  }
}

the controller:

// user.controller.ts
import { Controller, Get, Query } from "@nestjs/common";
import { UserService } from "./user.service";
import { IsEmail, IsOptional } from "class-validator";
import { MongoQueryModel } from "nest-mongo-query-parser";

class UserQueryModel extends MongoQueryModel {
  @IsOptional()
  @IsEmail()
  email: string;
}

@Controller("user")
export class UserController {
  constructor(private readonly service: UserService) {
  }

  @Get()
  findAll(@Query() query: UserQueryModel) {
    return this.service.find(query);
  }
}

So we have two situations here:

GET /user?email=me@mail.com

Response (ok):

{
   "limit":100,
   "skip":0,
   "select":{},
   "sort":{},
   "populate":[],
   "filter":{
      "email":"me@mail.com"
   }
}

GET /user?email=wrongmail

Response (bad request):

{
   "statusCode":400,
   "message":[
      "email must be an email"
   ],
   "error":"Bad Request"
}

Just be careful about the usage rules, to validate fields properly!

[j-vitali]

very good yes, I used that approach! thank you very much! one more thing, extending MongoQueryModel inside the DTO class is wrong?

import { IsOptional, IsString } from 'class-validator';
import { MongoQueryModel } from '@/common/query-parser' ;

export class SearchDTO extends MongoQueryModel{
  @IsString()
  @IsOptional()
  readonly name: string;

  @IsString()
  @IsOptional()
  readonly industry: string;

  @IsString()
  @IsOptional()
  readonly description: string;    

  @IsString()
  @IsOptional()
  readonly demo: string;  
}

[lucasrochagit]

very good yes, I used that approach! thank you very much! one more thing, extending MongoQueryModel inside the DTO class is wrong?

import { IsOptional, IsString } from 'class-validator';
import { MongoQueryModel } from '@/common/query-parser' ;

export class SearchDTO extends MongoQueryModel{
  @IsString()
  @IsOptional()
  readonly name: string;

  @IsString()
  @IsOptional()
  readonly industry: string;

  @IsString()
  @IsOptional()
  readonly description: string;    

  @IsString()
  @IsOptional()
  readonly demo: string;  
}

I don't think it's wrong, because MongoQueryModel is just a class with a few methods that updates itself fields and only represents the parsed query fields from MongoQueryParser operation.

Just remember put the IsOptional decoration on each SearchDTO. If you forgot to put the decorator in some field, the field becomes required, and it's not a good idea for query fields.

[j-vitali]

thanks a lot, appreciate your effort. for the moment i'll keep as you suggested, then when you will introduce DTO support i will change 💯