Function: paginator()

paginator<Options, T>(options, handler): Promise<PaginationResultDTO<T, T[]>>

Fetch a page of items with a handler, and build the paginated result: the items, with the page metadata (count the number of items returned, total the handler's total, and the limit and offset of the search). It does not validate the search: pass a validated PaginationSearchDTO (the input of an action, or a constructed DTO), whose limit and offset have their defaults (10 and 0).

Type Parameters

Options

Options extends PaginationSearchDTO

T

T

Parameters

options

Options

The search, a PaginationSearchDTO or a subclass carrying the search criteria.

handler

(limit, offset, options) => Promise<PaginatorHandlerResult<T>>

A function receiving the limit, the offset and the whole search, and resolving to the page of items and the total; its rejection rejects the paginator.

Returns

Promise<PaginationResultDTO<T, T[]>>

A promise of the paginated result (a plain object shaped as PaginationResultDTO).

Example

import {DTO} from 'lakutata'
import {Expect} from 'lakutata/decorator/dto'
import {PaginationResultDTO, PaginationSearchDTO, paginator} from 'lakutata/dtos'

class UserSearchDTO extends PaginationSearchDTO {
    @Expect(DTO.String().optional())
    public name?: string
}

interface User {
    id: number
    name: string
}

declare const db: {
    countUsers(name?: string): Promise<number>
    findUsers(name: string | undefined, limit: number, offset: number): Promise<User[]>
}

export async function SearchUsers(input: Record<string, unknown>): Promise<PaginationResultDTO<User>> {
    return await paginator(new UserSearchDTO(input), async (limit: number, offset: number, search: UserSearchDTO) => ({
        total: await db.countUsers(search.name),
        items: await db.findUsers(search.name, limit, offset)
    }))
}