Bringing the impressive work of the Rails' Webpacker project to be available for frameworks other than Rails. This is done by mocking the minimal amount of Rails for the Webpacker's Rake commands to be able to run.

Webpacker itself takes Webpack, which has a primary focus for pre-processing JavaScript related code, and make pre-processing other kinds of files such as CSS, SASS, Images, VueJS, React, CoffeeScript, and other similar content as simple as a couple very minor edits. Without Webpacker you would need to go through quite a bit of extra work to get Webpack to handle non JS items.

This project makes asset packing and cache invalidation easy for any web framework by bringing Webpacker's tooling to the command line. This cli tool is not meant to be used in a Rails project (at least not until it's designed to not overwrite a few files that exist in Rails).

This project has the same dependencies/prerequisites as Webpacker.

Install it yourself as:

$ gem install webpacker_cli

Note: If you have trouble compiling the Nokogiri dependency on Linux try installing the following packages: build-essential ruby-dev libxml2-dev

General help is found with

$ webpacker-cli --help

The help menu will change after initialization within the project directory.

And get started using it in your target project with:

$ webpacker-cli init

This creates the minimum files for Webpacker to work and runs bundle & rake webpacker:install. From here you have your configuration files for Webpack/Webpacker in the config directory.

To compile your assets you may now run:

$ webpacker-cli compile

To add support for another file type you can add a file to the config/webpack/loaders directory. Then load it from config/webpack/environment.js and lastly add the file extension to the config/webpacker.yml under default.extensions. Be sure to add the JS package with a command like yarn add.

Server Tip: It is recommended to compile your assets upon deploy rather than per web request.

Once your assets are compiled for deployment you will need to have your web application route the assets by the file stored in public/packs/manifest.json which will look similar to:

{
  "application.js": "/packs/application-9578bdd78b657fa4358f.js",
  "application.js.map": "/packs/application-9578bdd78b657fa4358f.js.map"
}

This way Webpacker handles cache invalidation for you whenever you make changes to your assets. So the manifest.json is the key-value pair of data used to be substitued in your web page views for the src references.

For a good example of using this tool for integrating with your own language see webpacker-rs. This library uses this tool to add Webpacker as part of the default build process of web deployment for the Rust language. In essence the user theirself is responsible for running webpacker-cli init and then webpacker-rs has two methods for deployment which validate dependencies on the server and then compile the assets. After deployment then webpacker-rs also provides a method for looking up the file mappings from the manifest.json file and provides a convenience helper method for dealing with the path routing.

Bug reports and pull requests are welcome on GitHub at https://github.com/danielpclark/webpacker-cli

The gem is available as open source under the terms of the GNU Lesser General Public License version 3.