Class variants

We ❤️ Tailwind CSS but sometimes it's difficult to manage the state of some elements using conditionals. class_variants is a tiny helper that should enable you to create, configure, and apply different variants of elements as classes.

Inspired by variant-classnames ✌️

Quicklinks

• DRY up your tailwind CSS using this awesome gem

Installation

Add this line to your application's Gemfile:

gem 'class_variants'

And then execute:

$ bundle

Or install it yourself as:

$ gem install class_variants

Usage

We create an object from the class or helper where we define the configuration using four arguments:

1. The base keyword argument with default classes that should be applied to each variant.
2. The variants keyword argument where we declare the variants with their option and classes.
3. The compound_variants keyword argument where we declare the compound variants with their conditions and classes
4. The defaults keyword argument (optional) where we declare the default value for each variant.

Example

Below we implement the button component from Tailwind UI.

# Define the variants and defaults
button_classes = ClassVariants.build(
  base: "inline-flex items-center rounded border border-transparent font-medium text-white hover:text-white shadow-sm focus:outline-none focus:ring-2 focus:ring-offset-2",
  variants: {
    size: {
      sm: "px-2.5 py-1.5 text-xs",
      md: "px-3 py-2 text-sm",
      lg: "px-4 py-2 text-sm",
      xl: "px-4 py-2 text-base",
    },
    color: {
      indigo: "bg-indigo-600 hover:bg-indigo-700 focus:ring-indigo-500",
      red: "bg-red-600 hover:bg-red-700 focus:ring-red-500",
      blue: "bg-blue-600 hover:bg-blue-700 focus:ring-blue-500",
    },
    # A variant whose value is a string will be expanded into a hash that looks
    # like  { true => "classes" }
    block: "w-full justify-center",
    # Unless the key starts with !, in which case it will expand into
    # { false => "classes" }
    "!block": "w-auto",
  },
  defaults: {
    size: :md,
    color: :indigo,
    icon: false
  }
)

# Call it with our desired variants
button_classes.render(color: :blue, size: :sm)
button_classes.render
button_classes.render(color: :red, size: :xl, icon: true)

Compound Variants

button_classes = ClassVariants.build(
  base: "inline-flex items-center rounded",
  variants: {
    color: {
      red:  "bg-red-600",
      blue: "bg-blue-600",
    },
    border: "border"
  },
  compound_variants: [
    { color: :red,  border: true, class: "border-red-800"  },
    { color: :blue, border: true, class: "border-blue-800" }
  ]
)

button_classes.render(color: :red) # => "inline-flex items-center rounded bg-red-600"
button_classes.render(color: :red, border: true) # => "inline-flex items-center rounded bg-red-600 border border-red-600"

Use with Rails

# Somewhere in your helpers
def button_classes(classes, **args)
  class_variants(
    base: "inline-flex items-center rounded border border-transparent font-medium text-white hover:text-white shadow-sm focus:outline-none focus:ring-2 focus:ring-offset-2",
    variants: {
      size: {
        sm: "px-2.5 py-1.5 text-xs",
        md: "px-3 py-2 text-sm",
        lg: "px-4 py-2 text-sm",
        xl: "px-4 py-2 text-base",
      },
      color: {
        indigo: "bg-indigo-600 hover:bg-indigo-700 focus:ring-indigo-500",
        red: "bg-red-600 hover:bg-red-700 focus:ring-red-500",
        blue: "bg-blue-600 hover:bg-blue-700 focus:ring-blue-500",
      },
    },
    defaults: {
      size: :md,
      color: :indigo,
    }
  )
end

<!-- In your views -->
<%= link_to :Avo, "https://avohq.io", class: button_classes.render(color: :blue, size: :sm) %>
<%= link_to :Avo, "https://avohq.io", class: button_classes.render %>
<%= link_to :Avo, "https://avohq.io", class: button_classes.render(color: :red, size: :xl) %>

Output

Other packages

• active_storage-blurhash - A plug-n-play blurhash integration for images stored in ActiveStorage
• avo - Build Content management systems with Ruby on Rails
• prop_initializer - A flexible tool for defining properties on Ruby classes.
• stimulus-confetti - The easiest way to add confetti to your StimulusJS app

Try Avo ⭐️

If you enjoyed this gem try out Avo. It helps developers build Internal Tools, Admin Panels, CMSes, CRMs, and any other type of Business Apps 10x faster on top of Ruby on Rails.

Contributing

1. Fork it git clone https://github.com/avo-hq/class_variants
2. Create your feature branch git checkout -b my-new-feature
3. Commit your changes git commit -am 'Add some feature'
4. Push to the branch git push origin my-new-feature
5. Create new Pull Request

License

This package is available as open source under the terms of the MIT License.

Cutting a release

# Build
gem build class_variants.gemspec -o latest.gem
# Publish
gem push --host https://rubygems.org/ ./latest.gem
# Cut a tag
git tag v0.0.6 -a -m "Version 0.0.6"
# Push tag to repo
git push --follow-tags
# Go to the repo and generate release from tag