BIG WARNING: as of 2016-08-02 17:30

This is Alpha code that will change rapidly throughout 2016 as I work on it. Do not use this in a production system until it has reached a stable 1.0.0 version (sometime near the end of 2016).


This is a custom implementation of the Google Material Design Spec.

It is built from the ground-up trying to use best practices but is still a work-in-progress. I extracted this code to a gem so I could use it in several projects simultaneously without updating code in each of them.

It is only engineered to support the latest browser versions that auto-update. Basically that means Internet Explorer 10+ and Edge, because all other major browsers already auto-update and usually follow the specs set forth for CSS.


Add this line to your application's Gemfile:

gem 'dlegr250_material_design'

And then execute:

$ bundle

Or install it yourself as:

$ gem install dlegr250_material_design


Add this line to your application's app/assets/javascripts/application.js:

//= require dlegr250_material_design

Add this line to your application's app/assets/stylesheets/application.scss:

@import "dlegr250_material_design";

Note that this assumes you renamed the default application.css to application.SCSS to utilize SASS/SCSS.

Using the .scss extension lets you control the order in which files are loaded/imported, which is a very good thing. This lets you use variables later on that were defined once in a previous file.

If you aren't using .scss extensions on all your stylesheets, you're doing it wrong ;)p

Application Default Variables

The gem uses SASS variables to set standard defaults for your application. This allows you to change major colors by simply changing a single variable.

In your application.scss file, before you import the library, set your variables. This mechanism relies upon SASS default variables that fall back to standard defaults if you do not specify them.

$body-background-color: #eee;
$primary-color: blue;
$secondary-color:  red;
$hover-color: grey;
$appbar-text-color: #fff;
$appbar-button-color: darkblue;

@import "dlegr250_material_design";

This changes the defaults for major layout elements or colored components by changing the color("primary") SASS map value.

Note that you can always override an element's color or background color using the color-{COLOR} or background-color-{COLOR} CSS classes that override whatever other defaults the element has.


  • Finalize components that will be implemented
  • Test in major browser versions and mobile devices
  • Styleguide to demo usage and components
  • Optimize file sizes
  • Create custom Snackbar component instead of using third-party
  • Update JS/CoffeeScript to use ES6 when that becomes mainstream, and IF the Rails Core is going to adopt ES6 as a standard; this gem is more about building Rails applications than using a specific JavaScript implementation
  • Remove jQuery dependency (requires updating any 3rd-party plugins that depend on jQuery, so may take a while)


Note that there are no specs for this UI library yet, and I'm not entirely sure how I would write "specs" for a UI...I think the styleguide will mostly be my "spec" checker.

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to


Bug reports and pull requests are welcome on GitHub at