koa-pagination

Koa Pagination

Koa Pagination is a middleware to handle Range Pagination Headers using Range & Content-Range entity-headers.

Installation

Choose your preferred method:

• npm: npm install --save koa-pagination
• Download: koa-pagination

Configuration

The middleware can be configured with the following parameters:

• Maximum: Maximum number of items allowed per page (50 by default).
• Unit: Range unit to be used when no Range header is provided (items by default).

You can change the defaults by doing:

paginate({
  maximum: 100,
  unit: 'bytes'
});

Usage

var koa = require('koa');
var paginate = require('koa-pagination');

var app = koa();

app.get('/', paginate(), function *() {
  // `paginate` middleware will inject a `pagination` object in the `koa` context,
  // which will allow you to use the `pagination.offset` and `pagination.limit`
  // in your data retrieval methods.
  this.body = foobar.getData({
    limit: this.pagination.limit,
    offset: this.pagination.offset
  });

  // This is needed in order to expose the length in `Content-Range` header.
  this.pagination.length = foobar.count();
});

app.listen(3000);

Request

You can provide the Range header specifying the items you want to retrieve. For instance to retrieve the first 5 elements:

'Range: items=0-5'

Response

This will generate a response with the following Content-Range header:

'Content-Range: items 0-5/*'

The * will be replaced with the total number of items provided in the length variable.

Running tests

npm test