Web Bundles

This is a Node.js module for serializing and parsing the application/webbundle
format defined in the
Web Bundles
draft spec.

Installation

Using npm:

``bash
npm install wbn
`

Usage

Please be aware that the API is not yet stable and is subject to change any
time.

Creating a Bundle:

`javascript
import * as fs from 'fs';
import * as wbn from 'wbn';

const builder = new wbn.BundleBuilder();
builder.addExchange(
'https://example.com/', // URL
200, // response code
{ 'Content-Type': 'text/html' }, // response headers
'Hello, Web Bundle!' // response body (string or Uint8Array)
);
builder.setPrimaryURL('https://example.com/'); // entry point URL

fs.writeFileSync('out.wbn', builder.createBundle());
`

Reading a Bundle:

`javascript
import * as fs from 'fs';
import * as wbn from 'wbn';

const buf = fs.readFileSync('out.wbn');
const bundle = new wbn.Bundle(buf);
const exchanges = [];
for (const url of bundle.urls) {
const resp = bundle.getResponse(url);
exchanges.push({
url,
status: resp.status,
headers: resp.headers,
body: new TextDecoder('utf-8').decode(resp.body),
});
}
console.log(
JSON.stringify(
{
version: bundle.version, // format version
exchanges,
},
null,
2
)
);
`

CLI

This package also includes wbn command which lets you build a web bundle from
a local directory. For example, if you have all the necessary files for
https://example.com/ in static/ directory, run the following command:

`sh
$ wbn --dir static \
--baseURL https://example.com/ \
--output out.wbn
`

Run wbn --help for full options.

Note: currently this CLI only covers a subset of the functionality offered by
gen-bundle
Go tool.

$3

This module supports creating and parsing Web Bundles that follow different
draft versions of the format specification. In particular:

- version b2 follows
the latest version of the Web Bundles spec
(default)
- version b1 follows
the previous version of the Web Bundles spec

To create a new bundle with the b1 format, pass the version value to the
constructor:

`javascript
const builder = (new wbn.BundleBuilder('b1'))
.setPrimaryURL('https://example.com/')
.setManifestURL('https://example.com/manifest.json')
.addExchange(...);

fs.writeFileSync('out_b1.wbn', builder.createBundle());
`

Likewise, the wbn command can optionally take a --formatVersion b1 parameter
when creating a new Web Bundle.

This module also takes care of selecting the right format version automatically
when reading a bundle. Check the property bundle.version to know the decoded
bundle's format version.

Using Bundles

Generated bundles can be opened with web browsers supporting web bundles.

Chrome (79+) experimentally supports navigation to Web Bundles with some
limitations. See
this document
for more details.

Chrome (104+) supports