First actual import of code from Active Admin

Gemfile

@@ -2,3 +2,7 @@ source "http://rubygems.org"
 
 # Specify your gem's dependencies in arbre.gemspec
 gemspec
+
+group :test do
+  gem "rspec"
+end

README.rdoc

@@ -1,3 +1,34 @@
-Arbre - Coming Soon. For now, checkout Active Admin:
+= Arbre - Ruby Object Oriented HTML Views
 
-http://github.com/gregbell/active_admin
+Arbre is the DOM implemented in Ruby. This project is primarily used as
+the object oriented view layer in Active Admin.
+
+== 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>

arbre.gemspec

@@ -16,4 +16,6 @@ Gem::Specification.new do |s|
   s.test_files    = `git ls-files -- {test,spec,features}/*`.split("\n")
   s.executables   = `git ls-files -- bin/*`.split("\n").map{ |f| File.basename(f) }
   s.require_paths = ["lib"]
+
+  s.add_dependency("activesupport", ">= 3.0.0")
 end

lib/arbre.rb

@@ -1,2 +1,15 @@
+require 'active_support/core_ext/string/output_safety'
+require 'active_support/inflector'
+
 module Arbre
 end
+
+require 'arbre/element'
+require 'arbre/context'
+require 'arbre/html/attributes'
+require 'arbre/html/class_list'
+require 'arbre/html/tag'
+require 'arbre/html/text_node'
+require 'arbre/html/document'
+require 'arbre/html/html5_elements'
+require 'arbre/component'

lib/arbre/builder.rb

@@ -0,0 +1,80 @@
+module Arbre
+
+  # Include this module in any context to start building html.
+  #
+  #   assigns = {}
+  #   include Arbre::Builder
+  #   span("foo").to_s #=> "<span>foo</span>
+  #
+  # When you include the module, you are required to setup 2 variables:
+  #
+  # * assigns: This is a hash that includes local variables
+  # * helpers: This is an object that provides helper methods to all
+  #              objects within the context.
+  module Builder
+
+    module BuilderMethods
+      def build_tag(klass, *args, &block)
+        tag = klass.new(assigns, helpers)
+        tag.parent = current_dom_context
+
+        # If you passed in a block and want the object
+        if block_given? && block.arity > 0
+          # Set out context to the tag, and pass responsibility to the tag
+          with_current_dom_context tag do
+            tag.build(*args, &block)
+          end
+        else
+          # Build the tag
+          tag.build(*args)
+
+          # Render the blocks contents
+          if block_given?
+            with_current_dom_context tag do
+              append_return_block(yield)
+            end
+          end
+        end
+
+        tag
+      end
+
+      def insert_tag(klass, *args, &block)
+        tag = build_tag(klass, *args, &block)
+        current_dom_context.add_child(tag)
+        tag
+      end
+
+      def current_dom_context
+        @__current_dom_element_buffer__ ||= [self]
+        current_element = @__current_dom_element_buffer__.last
+        if current_element == self
+          self
+        else
+          current_element.current_dom_context
+        end
+      end
+
+      def with_current_dom_context(tag)
+        raise ArgumentError, "Can't be in the context of nil. #{@__current_dom_element_buffer__.inspect}" unless tag
+        current_dom_context # Ensure a context is setup
+        @__current_dom_element_buffer__.push tag
+        yield
+        @__current_dom_element_buffer__.pop
+      end
+      alias_method :within, :with_current_dom_context
+
+      # Appends the value to the current DOM element if there are no
+      # existing DOM Children and it responds to #to_s
+      def append_return_block(tag)
+        return nil if current_dom_context.children?
+
+        if !tag.is_a?(Arbre::Element) && tag.respond_to?(:to_s)
+          current_dom_context << Arbre::HTML::TextNode.from_string(tag.to_s)
+        end
+      end
+    end
+
+  end
+end
+

lib/arbre/component.rb

@@ -0,0 +1,22 @@
+module Arbre
+  class Component < Arbre::HTML::Div
+
+    # By default components render a div
+    def tag_name
+      'div'
+    end
+
+    def initialize(*)
+      super
+      add_class default_class_name
+    end
+
+    protected
+
+    # By default, add a css class named after the ruby class
+    def default_class_name
+      self.class.name.demodulize.underscore
+    end
+
+  end
+end

lib/arbre/context.rb

@@ -0,0 +1,52 @@
+require 'arbre/element'
+
+module Arbre
+  class Context < Element
+
+    def initialize(assigns = {}, helpers = nil, &block)
+      assigns.symbolize_keys!
+      super(assigns, helpers)
+      instance_eval &block
+    end
+
+    def indent_level
+      # A context does not increment the indent_level
+      super - 1
+    end
+
+    def bytesize
+      cached_html.bytesize
+    end
+    alias :length :bytesize
+
+    def respond_to?(method)
+      super || cached_html.respond_to?(method)
+    end
+
+    # Webservers treat Arbre::Context as a string. We override
+    # method_missing to delegate to the string representation
+    # of the html.
+    def method_missing(method, *args, &block)
+      if cached_html.respond_to? method
+        cached_html.send method, *args, &block
+      else
+        super
+      end
+    end
+
+    private
+
+    # Caches the rendered HTML so that we don't re-render just to
+    # get the content lenght or to delegate a method to the HTML
+    def cached_html
+      if defined?(@cached_html)
+        @cached_html
+      else
+        html = to_s
+        @cached_html = html if html.length > 0
+        html
+      end
+    end
+
+  end
+end