koa-mongoose-paginate

Query parameter based pagination for REST APIs built using koa and mongoose

Right now the only form of pagination supported is page number based pagination through the PageNumberPaginator class. Cursor-based pagionation may come in the future.

⚠️ This library is in an early stage of development so the API is subject to change.

Installation

npm i koa-mongoose-paginate

Example Usage

You can use a paginator with koa context and a mongoose model.

Here's an example of a controller for a route using the PageNumberPaginator:

const { PageNumberPaginator } = require('koa-mongoose-paginate');
const User = require('./models/user');

async function userList(ctx) {
  const { page, pageSize } = ctx.query;

  try {
    const paginator = new PageNumberPaginator(User, ctx, pageSize, 'dateCreated', 'asc');
    return paginator.get(page);
  } catch (error) {
    return raiseError(error);
  }
}

You can modify your response as necessary if you'd like by leveraging a response middleware.

Example Response

{   
  "results": [
    {
      "_id": "1bf4da7643543a0e90831ae2",
      "firstName": "John",
      "lastName": "Snow",
      "email": "[email protected]"
    },
    {
      "_id": "2ae4da7643543a0e90831ae1",
      "firstName": "Arya",
      "lastName": "Stark",
      "email": "[email protected]"
    },
    {
      "_id": "5bf4da7643543a0e90831ae5",
      "firstName": "Daenerys",
      "lastName": "Targaryen",
      "email": "[email protected]"
    },
    ...
  ],
  "pagination": {
    "totalPages": 5,
    "count": 100,
    "previous": null,
    "next": "http://localhost:3000/users/?page=2"
  }
}

Client Usage

A frontend client/app can pass the following query parameters to use pagination:

• page to access different pages of the response results

• pageSize to indicate a different number of results per page. By default this is 20 with a max limit of 100 per page. You can change this using environment variables (see below).

• Example Url: http://localhost:3000/users/?page=2&pageSize=100

Environment Variables

koa-mongoose-paginate comes with some default settings, you can choose to override them if you'd like. Here are the list of variables you can modify:

Name | Default | Type | Required ----------------------------|------------|----------|--------- DEFAULT_PAGE_SIZE | 20 | Number | no MAX_PAGE_SIZE | 100 | Number | no
PAGE_QUERY_PARAMETER | "page" | String | no
PAGE_SIZE_QUERY_PARAMETER | pageSize | String | no

Author's Note

Inspiration for this library came from Django REST Framework