bagger

A framework agnostic packaging solution to speed up loading times on the client side by using the following techniques:

  • Generate versioned assets to maximize cache efficiency
  • Combine and minify javascript and css files to reduce bandwidth
  • Generate a file manifest to lookup an asset's location
  • Generate an HTML 5 cache manifest
  • Rewrite urls in css files with the versioned file name

Features already implemented in version 0.0.1

  • Combines javascript
  • Minfies javascript with UglifyJS
  • Combines stylesheets
  • Rewrites urls in stylesheets
  • Minfies stylesheets with rainpress
  • Generates versioned file names e.g /images/logo.19db9a16e2b73017c575570de577d103.png
  • Generates a manifest file in JSON
  • Generates an HTML 5 cache manifest

Installation

gem install bagger

Usage

require 'bagger'
require 'fileutils'

# define source and target directories
target_dir = "/tmp/bundled_assets"
source_dir = "/applications/my_app/public"

# customize paths for file and cache manifest
manifest_path = File.join(target_dir, 'file_manifest.json') # defaults to manifest.json

cache_manifest_path = 'cache/cache.manifest' # defaults to cache.manifest

# list the stylesheets and javascripts to be combined
# and minified. The order is important, because otherwhise
# the behavior of the stylesheets and javascripts might change
stylesheets = ["css/style.css", "css/reset.css"]
javascripts = ["js/app.js", "js/utils.js"]

# define cache manifest bundles for different devices
# for convenience, the manifest defined with `cache_manifest_path`
# will always contain all resources
ipad_resources = ["images/troll-big.png"]
iphone_retina_resources = ["images/troll-retina.png"]
desktop_browser_resources = ["images/troll.png"]

# make sure the target directory exists
FileUtils.mkdir_p target_dir

# define the options hash
options = {
    :source_dir => source_dir,
    :target_dir => target_dir,
    :manifest_path => manifest_path,
:gzip => false,
:verbose => false,
    :cache_manifest_path => cache_manifest_path,
        :path_prefix => '',
        :css_path_prefix => '',
        :exclude_pattern => /.*\.less/,
        :exclude_files => [ 'css/main.sass', 'css/style.sass' ]
    :combine => {
     :stylesheets => [
        {
          :target_path => 'css/all.css',
          :files => stylesheets
        }
      ],
     :javascripts => [
        {
          :target_path => 'js/combined.js',
          :files => javascripts
        }
      ]
    },
    :cache_manifests => [
      {
        :target_path => 'cache/ipad-cache.manifest',
        :files => ipad_resources
      },
      {
        :target_path => 'cache/retina-cache.manifest',
        :files => iphone_retina_resources
      },
      {
        :target_path => 'cache/desktop.manifest',
        :files => desktop_browser_resources
      }
    ]
}

# run it
Bagger::bagit!(options)

manifest_path = File.join(target_dir, 'manifest.json')
cache_manifest_path = File.join(target_dir, 'cache.json')

Manifest layout

{
  "/css/all.css" : "/css/all.19db9a16e2b73017c575570de577d103.css",
  "/js/combined.js" : "/js/combined.19db9a16e2b73017c575570de577d103.js",
  "/images/logo.png" : "/images/logo.19db9a16e2b73017c575570de577d103.png" 
}

HTML 5 cache manifest

CACHE MANIFEST

# Explicitely cached entries
/css/all.19db9a16e2b73017c575570de577d103.css
/js/combined.19db9a16e2b73017c575570de577d103.js
/images/.19db9a16e2b73017c575570de577d103.png

NETWORK:
*

Tests

check the build status on travis.ci

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