cat_herder

Minimal Rails asset pipeline experiment:

• Assets are fingerprinted and copied to public/assets in development, just like rails assets:precompile. Thus they are served directly, without any special routes or middleware.

• ERB assets are evaluated; all other assets are copied verbatim.

• ERB assets can call asset_path and all other AssetUrlHelper helpers.

  • Currently, *_url helpers always return a path instead of a full URL (the same as *_path helpers). Assuming these helpers are primarily used for import statements (e.g. @import url(...)), this shouldn't pose a problem, because the browser resolves such partial URLs to the asset host rather than the page host. The benefit of the current implementation is that it sidesteps the issue of cache invalidation when config.asset_host changes.

• ERB assets can call render to render the content of another asset inline.

• ERB assets can call glob to iterate over other assets. Using a given pattern, glob will search all load paths. With a combination of glob and render, assets can perform their own bundling.

• ERB assets can call resolve to get an absolute path to an asset file. This can be used to pass the asset to an external command, e.g.:

  <%# styles.css.erb %>
  <%= `sass #{resolve "styles.sass"}` %>

• All calls to asset_path / compute_asset_path, render, and resolve will add the resulting asset to the current asset's dependencies, so that the current asset will be recompiled when any of its dependencies are.

• Partial assets are prefixed with an underscore (like view partials), and are not copied to public/assets by rails assets:precompile. They can be referenced using their logical path without the underscore (like view partials). This allows "private" files, such as raw input files or config files, to be placed in any of the asset load paths and be evaluated like other assets. (Calls to compute_asset_path that resolve to a partial asset will raise an error to prevent broken URLs.)

Add this line to your application's Gemfile:

gem "cat_herder"

And run:

$ bundle install

Then disable Sprockets, and require cat_herder in your config/application.rb file:

require "cat_herder/railtie"

Run bin/test to run the tests.

MIT License