@taktikorg/maiores-dolores-aut

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
• Select columns
• Filter using operators ($eq, $not, $null, $in, $gt, $gte, $lt, $lte, $btw, $ilike, $sw, $contains)
• Include relations and nested relations
• Virtual column support

Installation

npm install @taktikorg/maiores-dolores-aut

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&select=id,name,color,age

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"
  }
}

Code

import { Controller, Injectable, Get } from '@nestjs/common'
import { InjectRepository } from '@nestjs/typeorm'
import { FilterOperator, FilterSuffix, Paginate, PaginateQuery, paginate, Paginated } from '@taktikorg/maiores-dolores-aut'
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

  @Column({ nullable: true })
  lastVetVisit: Date | null

  @CreateDateColumn()
  createdAt: string
}

@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',
      defaultSortBy: [['id', 'DESC']],
      searchableColumns: ['name', 'color', 'age'],
      select: ['id', 'name', 'color', 'age', 'lastVetVisit'],
      filterableColumns: {
        name: [FilterOperator.EQ, FilterSuffix.NOT],
        age: true,
      },
    })
  }
}

@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'
   * Description: 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: (keyof CatEntity)[]
   * Default: None
   * Description: TypeORM partial selection. Limit selection further by using `select` query param.
   * https://typeorm.io/select-query-builder#partial-selection
   * Note: You must include the primary key in the selection.
   */
  select: ['id', 'name', 'color'],

  /**
   * Required: false
   * Type: number
   * Default: 100
   * Description: The maximum amount of entities to return per page.
   * Set it to 0, in conjunction with limit=0 on query param, to disable pagination.
   */
  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
   * Default: false
   * Description: Load eager relations using TypeORM's eager property.
   * Only works if `relations` is not defined.
   */
  loadEagerRelations: true,

  /**
   * 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: string
   * Description: Allow user to choose between limit/offset and take/skip.
   * Default: PaginationType.TAKE_AND_SKIP
   *
   * However, using limit/offset can cause problems with relations.
   */
  paginationType: PaginationType.LIMIT_AND_OFFSET,

  /**
   * 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',

  /**
   * Required: false
   * Type: boolean
   * Default: false
   * Description: Prevent `searchBy` query param from limiting search scope further. Search will depend upon `searchableColumns` config option only
   */
  ignoreSearchByInQueryParam: true,

  /**
   * Required: false
   * Type: boolean
   * Default: false
   * Description: Prevent `select` query param from limiting selection further. Partial selection will depend upon `select` config option only
   */
  ignoreSelectInQueryParam: true,
}

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)

Note: Embedded columns on relations have to be wrapped with brackets:

const config: PaginateConfig<CatEntity> = {
  sortableColumns: ['id', 'name', 'toys.(size.height)', 'toys.(size.width)'],
  searchableColumns: ['name'],
  relations: ['toys'],
}

Usage with Nested Relations

Similar as with relations, you can specify nested relations for sorting, filtering and searching:

Example

Endpoint

http://localhost:3000/cats?filter.home.pillows.color=pink

Code

const config: PaginateConfig<CatEntity> = {
  relations: { home: { pillows: true } },
  sortableColumns: ['id', 'name', 'home.pillows.color'],
  searchableColumns: ['name', 'home.pillows.color'],
  filterableColumns: {
    'home.pillows.color': [FilterOperator.EQ],
  },
}

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

Usage with Eager Loading

Eager loading should work with TypeORM's eager property out of the box:

Example

Code

@Entity()
export class CatEntity {
  // ...

  @OneToMany(() => CatToyEntity, (catToy) => catToy.cat, {
    eager: true,
  })
  toys: CatToyEntity[]
}

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

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

Filters

Filter operators must be whitelisted per column in PaginateConfig.

Examples

Code

const config: PaginateConfig<CatEntity> = {
  // ...
  filterableColumns: {
    // Enable individual operators on a column
    id: [FilterOperator.EQ, FilterSuffix.NOT],

    // Enable all operators on a column
    age: true,
  },
}

?filter.name=$eq:Milo is equivalent with ?filter.name=Milo

?filter.age=$btw:4,6 where column age is between 4 and 6

?filter.id=$not:$in:2,5,7 where column id is not 2, 5 or 7

?filter.summary=$not:$ilike:term where column summary does not contain term

?filter.summary=$sw:term where column summary starts with term

?filter.seenAt=$null where column seenAt is NULL

?filter.seenAt=$not:$null where column seenAt is not NULL

?filter.createdAt=$btw:2022-02-02,2022-02-10 where column createdAt is between the dates 2022-02-02 and 2022-02-10

?filter.createdAt=$lt:2022-12-20T10:00:00.000Z where column createdAt is before iso date 2022-12-20T10:00:00.000Z

?filter.roles=$contains:moderator where column roles is an array and contains the value moderator

?filter.roles=$contains:moderator,admin where column roles is an array and contains the values moderator and admin

Multi Filters

Multi filters are filters that can be applied to a single column with a comparator.

Examples

?filter.createdAt=$gt:2022-02-02&filter.createdAt=$lt:2022-02-10 where column createdAt is after 2022-02-02 and before 2022-02-10

?filter.id=$contains:moderator&filter.id=$or:$contains:admin where column roles is an array and contains moderator or admin

?filter.id=$gt:3&filter.id=$and:$lt:5&filter.id=$or:$eq:7 where column id is greater than 3 and less than 5 or equal to 7

Note: The $and comparators are not required. The above example is equivalent to:

?filter.id=$gt:3&filter.id=$lt:5&filter.id=$or:$eq:7

Note: The first comparator on the the first filter is ignored because the filters are grouped by the column name and chained with an $and to other filters.

...&filter.id=5&filter.id=$or:7&filter.name=Milo&...

is resolved to:

WHERE ... AND (id = 5 OR id = 7) AND name = 'Milo' AND ...

Swagger

You can use two default decorators @ApiOkResponsePaginated and @ApiPagination to generate swagger documentation for your endpoints

@ApiOkPaginatedResponse is for response body, return http status is 200

@ApiPaginationQuery is for query params

  @Get()
  @ApiOkPaginatedResponse(
    UserDto,
    USER_PAGINATION_CONFIG,
  )
  @ApiPaginationQuery(USER_PAGINATION_CONFIG)
  async findAll(
    @Paginate()
    query: PaginateQuery,
  ): Promise<Paginated<UserEntity>> {

  }

There is also some syntax sugar for this, and you can use only one decorator @PaginatedSwaggerDocs for both response body and query params

  @Get()
  @PaginatedSwaggerDocs(UserDto, USER_PAGINATION_CONFIG)
  async findAll(
    @Paginate()
    query: PaginateQuery,
  ): Promise<Paginated<UserEntity>> {

  }

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).