Vulcanize

Concatenate a set of Web Components into one file

Named for the Vulcanization process that turns polymers into more durable materials.

Installation

vulcanize is available on npm. For maximium utility, vulcanize should be installed globally.

sudo npm install -g vulcanize

This will install vulcanize to /usr/local/bin/vulcanize.

Usage

vulcanize index.html

At the simplest, vulcanize only requires an html file as an argument. The optimized output file will be named vulcanized.html.

If you want to control the output name, use the -o flag

vulcanize -o build.html index.html

Most URLs will be automatically adjusted by the vulcanizer.

Options

--output, -o
Output file name (defaults to vulcanized.html)
--verbose, -v
More verbose logging
--help, -v, -?
Print this message
--config
- Read a given config file
--strip, -s
- Remove comments and empty text nodes
--csp
Extract inline scripts to a separate file (uses <output file name>.js)
--inline
The opposite of CSP mode, inline all assets (script and css) into the document
--inline --csp
- Bundle all javascript (inline and external) into <output file name>.js

Config

JSON file for additional options

Excludes: Exclude the selected urls from vulcanization (urls are still deduplicated for imports).

Example Config

{
  "excludes": {
    "imports": [
      "regex-to-exclude"
    ]
  }
}

Example Usage

Say we have three html files: index.html, x-app.html, and x-dep.html.

index.html:

<!DOCTYPE html>
<link rel="import" href="x-app.html">
<x-app></x-app>

x-app.html:

<link rel="import" href="path/to/x-dep.html">
<polymer-element name="x-app">
  <template>
    <x-dep></x-dep>
  </template>
  <script>Polymer('x-app')</script>
</polymer-element>

x-dep.html:

<polymer-element name="x-dep">
  <template>
    <img src="x-dep-icon.jpg">
  </template>
  <script>
    Polymer('x-dep');
  </script>
</polymer-element>

Running vulcan on index.html, and specifying build.html as the output:

vulcanize -o build.html index.html

Will result in build.html that appears as so:

<!DOCTYPE html>
<polymer-element name="x-dep" assetpath="path/to/">
  <template>
    <img src="path/to/x-dep-icon.jpg">
  </template>
  <script>
    Polymer('x-dep');
  </script>
</polymer-element>
<polymer-element name="x-app" assetpath="">
  <template>
    <x-dep></x-dep>
  </template>
  <script>
    Polymer('x-app');
  </script>
</polymer-element>
<x-app></x-app>

Content Security Policy

Content Security Policy, or CSP, is a Javascript security model that aims to prevent XSS and other attacks. In so doing, it prohibits the use of inline scripts.

To help automate the use of Polymer element registration with CSP, the --csp flag to vulcan will remove all scripts from the HTML Imports and place their contents into an output javascript file.

Using the previous example, the output from vulcanize --csp -o build.html index.html will be

build.html:

<!DOCTYPE html>
<polymer-element name="x-dep" assetpath="path/to/">
  <template>
    <img src="path/to/x-dep-icon.jpg">
  </template>
</polymer-element>
<polymer-element name="x-app" assetpath="">
  <template>
    <x-dep></x-dep>
  </template>
</polymer-element>
<script src="build.js"></script>
<x-app></x-app>

build.js:

Polymer('x-dep');
Polymer('x-app');

pdelanauze / vulcanize