DTOs

REST DTOs describe response serialization, request validation, OpenAPI schemas, identifiers, and the fields accepted as filters. The decorators combine metadata from @nestjs/swagger, class-transformer, and class-validator.

@Field

Use @Field for properties exposed in request or response schemas. The decorator infers primitive types from TypeScript metadata and accepts Swagger property options such as description, example, nullable, minLength, maxLength, minimum, maximum, and enum.

todo-item-input.dto.ts

import { Field } from '@ptc-org/nestjs-query-rest'

export class TodoItemInputDTO {
  @Field({ description: 'A short task title', maxLength: 100 })
  title!: string

  @Field({ default: false })
  completed!: boolean
}

For nested objects and arrays, provide an explicit return type:

export class LabelDTO {
  @Field()
  name!: string
}

export class TodoItemDTO {
  @Field(() => [LabelDTO])
  labels!: LabelDTO[]
}

Set nullable: true on optional update properties. Required fields receive validation metadata by default.

@FilterableField

@FilterableField includes the property in the schema just like @Field and exposes it as an equality query parameter on collection and export endpoints.

todo-item.dto.ts

import { Field, FilterableField, IDField } from '@ptc-org/nestjs-query-rest'

export class TodoItemDTO {
  @IDField()
  id!: number

  @FilterableField()
  title!: string

  @FilterableField()
  completed!: boolean

  @Field()
  created!: Date
}

The DTO above accepts requests such as:

GET /todo-items?completed=false&title=Write%20docs

Additional filter options include:

• filterRequired: true makes the query parameter mandatory whenever the generated filter is used.
• filterOnly: true accepts the property as a filter but excludes it from serialized response fields.
• filterDecorators applies additional decorators to the generated query property.
• Standard Field/Swagger options control transformation and validation.

export class TodoItemDTO {
  @FilterableField({ filterRequired: true })
  tenantId!: string

  @FilterableField({ filterOnly: true })
  internalStatus!: string
}

@IDField

@IDField identifies the property used by GET, PUT, and DELETE single-record routes. Declare it on the response DTO so the generated :id parameter is transformed to the correct type.

export class TodoItemDTO {
  @IDField()
  id!: number
}

Use idOnly: true when an identifier should be accepted as a route parameter but omitted from generated mutation bodies.

@QueryOptions

Use @QueryOptions to set collection defaults on the DTO. Endpoint-level options override decorator options.

import { SortDirection } from '@ptc-org/nestjs-query-core'
import { FilterableField, IDField, PagingStrategies, QueryOptions } from '@ptc-org/nestjs-query-rest'

@QueryOptions({
  pagingStrategy: PagingStrategies.OFFSET,
  defaultResultSize: 20,
  maxResultsSize: 100,
  defaultSort: [{ field: 'created', direction: SortDirection.DESC }],
  enableTotalCount: true
})
export class TodoItemDTO {
  @IDField()
  id!: number

  @FilterableField()
  created!: Date
}

See filtering and paging for the generated HTTP API.