pootsbook/html_document.rb

## html_document.rb
class HTMLDocument
  ENTITIES = {
    "'" => '&#39;',
    '&' => '&amp;',
    '"' => '&quot;',
    '<' => '&lt;',
    '>' => '&gt;',
  }

  def initialize(indent = "  ", level = 0)
    @doc = ""
    @indent = indent
    @level = level

    yield self if block_given?
  end

  def text(string)
    @doc << "#{@indent * @level}#{escape(string)}\n"
  end

  def el(type, attrs={})
    indentation = @indent * @level
    if block_given?
      @doc << "#{indentation}<#{type}#{attributes(attrs)}>\n"
      @level += 1
      yield
      @level -= 1
      @doc << "#{indentation}</#{type}>\n"
    else
      @doc << "#{indentation}<#{type}#{attributes(attrs)} />\n"
    end
  end

  def to_s
    @doc
  end

  def attributes(attrs)
    attrs.map do |key, value|
      case value
      when false
      when true
        %[ #{key}]
      else
        %[ #{key}="#{escape(value.to_s)}"]
      end
    end.join
  end

  def escape(str)
    str.gsub(/['&\"<>]/, ENTITIES)
  end
end

doc = HTMLDocument.new do |d|
  d.el :html, lang: "en-GB" do
    d.el :head do
      d.el :title do
        d.text "Hello, World!"
      end
    end
    d.el :body do
      d.el :input, { type: "text" }
    end
  end
end

puts doc.to_s

#=>
# <html lang="en-GB">
#   <head>
#     <title>
#       Hello, World!
#     </title>
#   </head>
#   <body>
#     <input type="text" />
#   </body>
# </html>
	class HTMLDocument
	ENTITIES = {
	"'" => ''',
	'&' => '&',
	'"' => '"',
	'<' => '<',
	'>' => '>',
	}

	def initialize(indent = " ", level = 0)
	@doc = ""
	@indent = indent
	@level = level

	yield self if block_given?
	end

	def text(string)
	@doc << "#{@indent * @level}#{escape(string)}\n"
	end

	def el(type, attrs={})
	indentation = @indent * @level
	if block_given?
	@doc << "#{indentation}<#{type}#{attributes(attrs)}>\n"
	@level += 1
	yield
	@level -= 1
	@doc << "#{indentation}</#{type}>\n"
	else
	@doc << "#{indentation}<#{type}#{attributes(attrs)} />\n"
	end
	end

	def to_s
	@doc
	end

	def attributes(attrs)
	attrs.map do \|key, value\|
	case value
	when false
	when true
	%[ #{key}]
	else
	%[ #{key}="#{escape(value.to_s)}"]
	end
	end.join
	end

	def escape(str)
	str.gsub(/['&\"<>]/, ENTITIES)
	end
	end

	doc = HTMLDocument.new do \|d\|
	d.el :html, lang: "en-GB" do
	d.el :head do
	d.el :title do
	d.text "Hello, World!"
	end
	end
	d.el :body do
	d.el :input, { type: "text" }
	end
	end
	end

	puts doc.to_s

	#=>
	# <html lang="en-GB">
	# <head>
	# <title>
	# Hello, World!
	# </title>
	# </head>
	# <body>
	# <input type="text" />
	# </body>
	# </html>