Nest.js Paginate

Pagination and filtering helper method for TypeORM repositories or query builders using Nest.js framework.

• Pagination conforms to JSON:API
• Sort by multiple columns
• Search across columns
• Filter using operators ($eq, $not, $null, $in, $gt, $gte, $lt, $lte, $btw, $ilike)
• Include relations

Installation

npm install nestjs-paginate

Usage

Example

The following code exposes a route that can be utilized like so:

Endpoint

http://localhost:3000/cats?limit=5&page=2&sortBy=color:DESC&search=i&filter.age=$gte:3

Result

{
  "data": [
    {
      "id": 4,
      "name": "George",
      "color": "white",
      "age": 3
    },
    {
      "id": 5,
      "name": "Leche",
      "color": "white",
      "age": 6
    },
    {
      "id": 2,
      "name": "Garfield",
      "color": "ginger",
      "age": 4
    },
    {
      "id": 1,
      "name": "Milo",
      "color": "brown",
      "age": 5
    },
    {
      "id": 3,
      "name": "Kitty",
      "color": "black",
      "age": 3
    }
  ],
  "meta": {
    "itemsPerPage": 5,
    "totalItems": 12,
    "currentPage": 2,
    "totalPages": 3,
    "sortBy": [["color", "DESC"]],
    "search": "i",
    "filter": {
      "age": "$gte:3"
    }
  },
  "links": {
    "first": "http://localhost:3000/cats?limit=5&page=1&sortBy=color:DESC&search=i&filter.age=$gte:3",
    "previous": "http://localhost:3000/cats?limit=5&page=1&sortBy=color:DESC&search=i&filter.age=$gte:3",
    "current": "http://localhost:3000/cats?limit=5&page=2&sortBy=color:DESC&search=i&filter.age=$gte:3",
    "next": "http://localhost:3000/cats?limit=5&page=3&sortBy=color:DESC&search=i&filter.age=$gte:3",
    "last": "http://localhost:3000/cats?limit=5&page=3&sortBy=color:DESC&search=i&filter.age=$gte:3"
  }
}

Array values for filter operators such as $in should be provided as comma-separated values:

http://localhost:3000/cats?filter.name=$in:George,Milo

Code

import { Controller, Injectable, Get } from '@nestjs/common'
import { InjectRepository } from '@nestjs/typeorm'
import { FilterOperator, Paginate, PaginateQuery, paginate, Paginated } from 'nestjs-paginate'
import { Repository, Entity, PrimaryGeneratedColumn, Column } from 'typeorm'

@Entity()
export class CatEntity {
  @PrimaryGeneratedColumn()
  id: number

  @Column('text')
  name: string

  @Column('text')
  color: string

  @Column('int')
  age: number
}

@Injectable()
export class CatsService {
  constructor(
    @InjectRepository(CatEntity)
    private readonly catsRepository: Repository<CatEntity>
  ) {}

  public findAll(query: PaginateQuery): Promise<Paginated<CatEntity>> {
    return paginate(query, this.catsRepository, {
      sortableColumns: ['id', 'name', 'color', 'age'],
      nullSort: 'last',
      searchableColumns: ['name', 'color', 'age'],
      defaultSortBy: [['id', 'DESC']],
      filterableColumns: {
        age: [FilterOperator.GTE, FilterOperator.LTE],
      },
    })
  }
}

@Controller('cats')
export class CatsController {
  constructor(private readonly catsService: CatsService) {}

  @Get()
  public findAll(@Paginate() query: PaginateQuery): Promise<Paginated<CatEntity>> {
    return this.catsService.findAll(query)
  }
}

Config

const paginateConfig: PaginateConfig<CatEntity> {
  /**
   * Required: true (must have a minimum of one column)
   * Type: (keyof CatEntity)[]
   * Description: These are the columns that are valid to be sorted by.
   */
  sortableColumns: ['id', 'name', 'color'],

  /**
   * Required: false
   * Type: 'first' | 'last'
   * Default: 'first'
   * Description: (ONLY WORKS WITH POSTGRES) Define whether to put null values
   * at the beginning or end of the result set.
   */
  nullSort: 'last',

  /**
   * Required: false
   * Type: [keyof CatEntity, 'ASC' | 'DESC'][]
   * Default: [[sortableColumns[0], 'ASC]]
   * Description: The order to display the sorted entities.
   */
  defaultSortBy: [['name', 'DESC']],

  /**
   * Required: false
   * Type: (keyof CatEntity)[]
   * Description: These columns will be searched through when using the search query
   * param. Limit search scope further by using `searchBy` query param.
   */
  searchableColumns: ['name', 'color'],

  /**
   * Required: false
   * Type: TypeORM partial selection
   * Default: None
   * https://typeorm.io/select-query-builder#partial-selection
   */
  select: ['name', 'color'],

  /**
   * Required: false
   * Type: number
   * Default: 100
   * Description: The maximum amount of entities to return per page.
   */
  maxLimit: 20,

  /**
   * Required: false
   * Type: number
   * Default: 20
   */
  defaultLimit: 50,

  /**
   * Required: false
   * Type: TypeORM find options
   * Default: None
   * https://typeorm.io/#/find-optionsfind-options.md
   */
  where: { color: 'ginger' },

  /**
   * Required: false
   * Type: { [key in CatEntity]?: FilterOperator[] } - Operators based on TypeORM find operators
   * Default: None
   * https://typeorm.io/#/find-options/advanced-options
   */
  filterableColumns: { age: [FilterOperator.EQ, FilterOperator.IN] },

  /**
   * Required: false
   * Type: RelationColumn<CatEntity>
   * Description: Indicates what relations of entity should be loaded.
   */
  relations: [],

  /**
   * Required: false
   * Type: boolean
   * Description: Disables the global condition of "non-deleted" for the entity with delete date columns.
   * https://typeorm.io/select-query-builder#querying-deleted-rows
   */
  withDeleted: false,

  /**
   * Required: false
   * Type: boolean
   * Default: false
   * Description: Generate relative paths in the resource links.
   */
  relativePath: true,

  /**
   * Required: false
   * Type: string
   * Description: Overrides the origin of absolute resource links if set.
   */
  origin: 'http://cats.example',
}

Usage with Query Builder

You can paginate custom queries by passing on the query builder:

Example

const queryBuilder = repo
  .createQueryBuilder('cats')
  .leftJoinAndSelect('cats.owner', 'owner')
  .where('cats.owner = :ownerId', { ownerId })

const result = await paginate<CatEntity>(query, queryBuilder, config)

Usage with Relations

Similar as with repositories, you can utilize relations as a simplified left-join form:

Example

Endpoint

http://localhost:3000/cats?filter.toys.name=$in:Mouse,String

Code

const config: PaginateConfig<CatEntity> = {
  relations: ['toys'],
  sortableColumns: ['id', 'name', 'toys.name'],
  filterableColumns: {
    'toys.name': [FilterOperator.IN],
  },
}

const result = await paginate<CatEntity>(query, catRepo, config)

Troubleshooting

The package does not report error reasons in the response bodies. They are instead reported as debug level logging.

Common errors include missing sortableColumns or filterableColumns (the latter only affects filtering).