hlx-url-rewriter

hlx-url-rewriter

A transform stream to modify URLs contained in HLS playlists

Features

• Being used with other hlx objects, it provides a functionality to filter every playlists and rewrite the urls in them based on the rules.

Install

Usage

const {createReadStream} = require('hlx-file-reader');
const {createUrlRewriter} = require('hlx-url-rewriter'); // url-rewriter
const {createTerminator} = require('hlx-terminator')

const src = createReadStream('https://foo.bar/sample.m3u8');
const rewrite = createUrlRewriter(data => {
  // Convert playlist's urls from absolute to relative
  if (data.type === 'playlist') {
    const url = new URL(data.uri);
    data.uri = url.pathname;
  }
});
const dest = createTerminator();

// Rewrite all urls
src.pipe(rewrite).pipe(dest)
.on('data', data => {
  console.log(data.uri); // should be a relative url
});

API

The features are built on top of the Node's transform streams.

createUrlRewriter([rules, options])

Creates a new TransformStream object.

params

Name	Type	Required	Default	Description
rules	function	No	internally defined default function (see below)	A function that takes an hls-parser object and modifies its url string.
options	function	No	see below	An object preserving options

default function

The default behavior is something like this:

// pseudo code
function defaultFunc(data) {
  if (data.uri is relative) {
    // Do nothing
  } else {
    // Put in a root directory
    const url = new URL(data.uri);
    data.uri = `/${url.hostname}/${url.pathname}`;
  }
}

options

Name	Type	Default	Description
rootPath	string	"/"	Required if file urls are included in playlists. A file url will be converted to an absolute path assuming the rootPath is the root.

return value

An instance of TransformStream.