Quince

Quince is an opinionated framework for building dynamic yet fully server-rendered web apps, with little to no JavaScript.

React, Turbo, Hotwire amongst others

Early, but working in production. Expect more features and optimisations to come, but also potential for big changes between versions in the early stages.

• Define some components and expose them at certain routes
• Define some interactions that can take place, which can change the state of the components, and are handled with ruby methods
• The front end will swap out the updated components with new HTML re-rendered by the back end

# app.rb
require "quince"

class App < Quince::Component
    def render
      html(
        head,
        body("hello world")
      )
    end
end

expose App, at: "/"

• Run it via

ruby app.rb

• Visit localhost:4567/!

require 'quince'

class App < Quince::Component
    def render
      Layout(title: "First app") {[
        Counter()
      ]}
    end
end

class Layout < Quince::Component
  Props(title: String)

  def render
      html(
        head(
            internal_scripts
        ),
        body(
            h1(props.title),
            children
        )
      )
  end
end

class Counter < Quince::Component
    State(val: Integer)

    def initialize
      @state = State.new(
          val: params.fetch(:val, 0),
      )
    end

    exposed def increment
        state.val += 1
    end

    exposed def decrement
        state.val -= 1
    end

    def render
        div(
            h2("count is #{state.val}"),
            button(onclick: callback(:increment)) { "++" },
            button(onclick: callback(:decrement)) { "--" }
        )
    end
end

expose App, at: "/"

• You have pre-existing APIs which you want to integrate a front end with
• You want to share the back end API with a different service
• You want more offline functionality
• You need a super complex/custom front end

• Components > templates 🧩
• Lightweight 🪶
• Shallow learning curve if you are already familiar with React 📈
• Focus on your core business logic, not routes/APIs/data transfer/code sharing 🧪
• No compilation/node_modules/yarn/js bundle size concerns - just bundler 📦
• Get full use of Ruby's rich and comprehensive standard library 💎
• Take advantage of Ruby's ability to wrap native libraries (eg. gems using C) ⚡️
• Fully server-rendered responses - single source of truth 📡
• Easy to recreate/rehydrate a pages state (almost nothing is stored in memory from JavaScript - all the state is stored with the HTML document's markup)

Add this to your application's Gemfile:

gem 'quince'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install quince

• All HTML tags are available via a method of the same name, eg. div(), section(), span() - with the exception of para standing in for p to avoid clashes with Ruby's common Kernel#p method
• All HTML attributes are available, and are the same as they would be in a regular html document, eg. onclick rather than onClick - with the exception of a Class, Max, Min, Method - which start with capital letters to avoid clashes with some internal methods.
• Type checking is available at runtime for a component's State and Props, and is done in accordance with Typed Struct
• Children can be specified in one of two places, depending on what you would prefer:
  • as a block argument, to maintain similar readability with real html elements, where attributes come first

    div(id: :my_div, style: "color: red") { h1("Single child") }
    div(id: "div2", style: "color: green") {[
        h2("multiple"),
        h3("children")
    ]}

  • as positional arguments (for convenience and cleanliness when no props are passed)

    div(
        h1("hello world")
    )

• A component's render method should always return a single top level element, ie. if you wanted to return 2 elements you should wrap them in a div

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 the created tag, and push the .gem file to rubygems.org.

Bug reports and pull requests are welcome on GitHub at https://github.com/johansenja/quince.

The gem is available as open source under the terms of the MIT License.