parse-link-header

What is parse-link-header?

The parse-link-header npm package is used to parse HTTP link headers, which are commonly used for pagination in APIs. It converts the link header string into a more manageable JavaScript object.

What are parse-link-header's main functionalities?

Parsing Link Headers

This feature allows you to parse a link header string into a JavaScript object. The example demonstrates parsing a GitHub API link header for pagination.

const parse = require('parse-link-header');
const linkHeader = '<https://api.github.com/user/repos?page=2&per_page=100>; rel="next", <https://api.github.com/user/repos?page=5&per_page=100>; rel="last"';
const parsed = parse(linkHeader);
console.log(parsed);

Other packages similar to parse-link-header

http-link-header

The http-link-header package provides similar functionality to parse-link-header by parsing HTTP link headers into a JavaScript object. It also offers additional methods to manipulate and format link headers.

link-header-parser

The link-header-parser package is another alternative that parses HTTP link headers. It focuses on simplicity and ease of use, providing a straightforward API for parsing link headers.

README

parse-link-header

Parses a link header and returns paging information for each contained link.

var parse = require('parse-link-header');

var linkHeader =
  '<https://api.github.com/user/9287/repos?page=3&per_page=100>; rel="next", ' +
  '<https://api.github.com/user/9287/repos?page=1&per_page=100>; rel="prev"; pet="cat", ' +
  '<https://api.github.com/user/9287/repos?page=5&per_page=100>; rel="last"'

var parsed = parse(linkHeader);
console.log(parsed);

{ next:
   { page: '3',
     per_page: '100',
     rel: 'next',
     url: 'https://api.github.com/user/9287/repos?page=3&per_page=100' },
  prev:
   { page: '1',
     per_page: '100',
     rel: 'prev',
     pet: 'cat',
     url: 'https://api.github.com/user/9287/repos?page=1&per_page=100' },
  last:
   { page: '5',
     per_page: '100',
     rel: 'last',
     url: 'https://api.github.com/user/9287/repos?page=5&per_page=100' } }

Installation

npm install parse-link-header

API

parseLinkHeader(linkHeader : String) : Object

Parses the given link header containing web links and returns an object keyed by the rel property that contains information about each link.

Environmental Variables

To avoid redundantly parsing of extremely long (invalid) input, the package uses 2 env variabes:

PARSE_LINK_HEADER_MAXLEN - Sets the number of characters the input should be limited to - longer inputs will not be handled. Defaults to 2000.

PARSE_LINK_HEADER_THROW_ON_MAXLEN_EXCEEDED - Defines behavior for when the PARSE_LINK_HEADER_MAXLEN parameter is exceeded. if defined, an error will be thrown; if it's null, the function fails silently by returning null. Defaults to null.

Formatting a link header

The purpose of this module is to parse the link header information. To format an object generated by this module back to the link header string, use the format-link-header module.