Arbre - Ruby Object Oriented HTML Views

Arbre is the DOM implemented in Ruby. This project is primarily used as the object oriented view layer in Active Admin.

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Simple Usage

A simple example of setting up an Arbre context and creating some html

html = Arbre::Context.new do
  h2 "Why Arbre is awesome?"

  ul do
    li "The DOM is implemented in ruby"
    li "You can create object oriented views"
    li "Templates suck"
  end
end

puts html.to_s #=> <h2>Why</h2><ul><li></li></ul>

The DOM in Ruby

The purpose of Arbre is to leave the view as ruby objects as long as possible. This allows OO Design to be used to implement the view layer.

html = Arbre::Context.new do
  h2 "Why Arbre is awesome?"
end

html.children.size #=> 1
html.children.first #=> #<Arbre::Html::H2>

It is easy to extend your DOM tree as well.

arbre = Arbre::Context.new do
  h2 "Why Arbre is awesome?"

  ul do
    li "The DOM is implemented in ruby"
    li "You can create object oriented views"
  end

  within 'ul' do
    li "Templates suck"
  end
  before 'li:last' do
    li "I forgot:"
  end
end

Custom elements

The purpose of Arbre is to be able to create shareable and extendable HTML elements. To do this, you create a subclass of any Arbre HTML element:

For example:

class Panel < Arbre::Html::Section
  builder_method :panel

  def build!(title, attributes = {})
    super attributes

    h3 title, class: "panel-title"
  end
end

The builder_method defines the method that will be called to build this component when using the DSL. The arguments passed into the builder_method will be passed into the #build! method for you.

You can now use this panel in any Arbre context:

html = Arbre::Context.new do
  panel "Hello World", id: "my-panel" do
    span "Inside the panel"

    after('h3') { sub "This is inserted after the title." }
  end
end

html.to_s #=>
  # <div class='panel' id="my-panel">
  #   <h3 class='panel-title'>Hello World</h3>
  #   <sub>This is inserted after the title.</sub>
  #   <span>Inside the panel</span>
  # </div>