baler is an AMD module bundler and preloader for Magento 2 stores.

• Improve client-side performance of all Magento 2 stores
• Require little to no configuration for a typical Magento 2 store
• Work against as many frontend themes are possible
• Be (and stay) fast

baler has two different strategies for optimizing JavaScript delivery.

The "core" bundle contains the code that baler can determine is critical to the first render of the page. This includes the Magento core libraries, along with some theme-specific and feature-specific code.

The JavaScript included in the "core" bundle only includes dependencies that can be statically-analyzed from a theme's requirejs-config.js. However, many parts of the Magento front-end are controlled by widgets that are specified using a declarative notation in .phtml files.

This is where Graph Preloading comes in. When baler is run, it crawls the file system and determines which .phtml are eligible to be used in a specific area (frontend/adminhtml/base). These templates are then analyzed for any AMD module dependencies.

When a graph of dependencies has been collected for each .phtml file, the lists are flattened and deduped against the "core" bundle. Then, when a shopper requests a page of your store, preload tags are injected that instruct the browser to immediately begin fetching necessary dependencies.

This has been discussed elsewhere, but this repository will eventually be the home of that documentation.

• Document Usage