parse-link-header

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

Note: This is a fork of github.com/thlorenz/parse-link-header with zero dependencies, no Node.js globals and ESM.

Install

npm install @web3-storage/parse-link-header

Usage

import { parseLinkHeader } from '@web3-storage/parse-link-header'

const 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"'

const parsed = parseLinkHeader(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' } }

API

parseLinkHeader(linkHeader: String, options?: Object): Object

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

The following options are available to avoid redundantly parsing of extremely long (invalid) input:

• maxHeaderLength: number - Sets the number of characters the input should be limited to - longer inputs will not be handled. Defaults to 2000.
• throwOnMaxHeaderLengthExceeded: boolean - Defines behavior for when the PARSE_LINK_HEADER_MAXLEN parameter is exceeded. if true, an error will be thrown; if it's false/null/undefined, the function fails silently by returning null. Defaults to false.

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.