koa-typeorm-pagination

• About
• Overview
  • Request
    • Query parameters
      • Pageable
      • Sort
    • Errors
• Getting Started
  • Installation
    • npm
    • yarn
  • Requirements
  • Examples
    • Router
    • Data Access
• API Documentation

About

It's fork koa-pageable but koa-pageable is unmaintained koa-typeorm-pagination is middleware for pagination in Koa inspired by Spring Data's Pagination support.

It allows clients of your API to easily request subsets of your data by providing query parameters to specify the amount, order, and formatting of the requested data. For instance, if you had an endpoint /people backed by a data store containing 1000 people records, koa-pageable allows a client to request the data be broken up into 10 person pages, and to receive 2nd page of people sorted by their lastname (GET /people?page=1&size=10&sort=lastname)

Overview

Request

Query parameters

When enabled this middleware parses request query parameters from ctx.query into an instance of Pageable.

These values are:

Parameter	Default Value	Description
current	0	The 0-indexed page to be retrieved
pageSize	20	Maximum number of elements to be included in the retrieved page
sort	undefined	Properties that should be sorted, in the specified order. Properties are separated by a , and directions are separated with a :. Valid directions are asc and desc and if not specified, direction defaults to asc. For example to sort by lastname ascending, then firstname descending: ?sort=lastname,firstname:desc

Pageable

The Pageable object created from the query parameters contains two integers, page & size, an optional Sort instance, and an indexed boolean. This pageable instance should be passed to your data access layer, and its content should be used to restrict the returned data to the data specified by the pageable.

Sort

Sort is a collection of property and direction( asc or desc) pairs. Each sort instance has a forEach(callback(property,direction)) method that invokes callback for each property/direction pair in the sort

Errors

If the page or size query parameter are not specified as valid numbers, a NumberFormatError will be thrown. If the sort direction is specified as anything other than asc or desc (e.g. sort=lastName:foo) then an InvalidSortError will be thrown.

Getting Started

Installation

npm

npm install koa-typeorm-pagination

yarn

yarn add koa-typeorm-pagination

Requirements

Requires node >= 8.2, as koa-pageable makes use of async/await. Typescript bindings are also provided.

koa-ctx-pageable is a convenient library for managing conversion of user intent (via request parameters) into a Pageable object, but it is still your responsibility to implement that intention when accessing data. You are responsible for ensuring that your data access tier properly implements the pagination and/or sorting, and for creating the Page instances to be returned. The exact approach for doing so will differ based on your chose Data Access framework.

Examples

Router

import { paginateMiddleware } from 'koa-typeorm-pagination';
import Koa from 'koa';

var app = new Koa();
app.use(paginateMiddleware);

Data Access

Example of using pageable as input to a query, and Page as the response type.

import { paginate, IPaginationOptions } from 'koa-typeorm-pagination';

async function getData(paginateOptions: IPaginationOptions) {
 
  const queryBuilder = Person.query().where('age', '>', 21);
  
  return await paginate(queryBuilder, paginateOptions); 
}