class Roadie::MarkupImprover

See github.com/sparklemotion/nokogiri/issues/984<br>@note Due to a Nokogiri bug, the HTML5 doctype cannot be added under JRuby. No doctype is outputted under JRuby.
* +<meta>+ declaring charset and content-type (text/html)
* +<body>+
* +<head>+
* +<html>+
* Basic HTML elements will be added if missing.
* A HTML5 doctype will be added if missing, other doctypes will be left as-is.
This class will improve the following aspects of the DOM:
Class that improves the markup of a HTML DOM tree
@api private

def content_type_meta_element_missing?

def content_type_meta_element_missing?
  dom.xpath('html/head/meta').none? do |meta|
    meta['http-equiv'].to_s.downcase == 'content-type'
  end
end

def create_head_element(parent)

def create_head_element(parent)
  head = Nokogiri::XML::Node.new 'head', dom
  unless parent.children.empty?
    # Crashes when no children are present
    parent.children.before head
  else
    parent << head
  end
  head
end

def ensure_declared_charset(parent)

def ensure_declared_charset(parent)
  if content_type_meta_element_missing?
    parent.add_child make_content_type_element
  end
end

def ensure_doctype_present

def ensure_doctype_present
  return if uses_buggy_jruby?
  return if @html.include?('<!DOCTYPE ')
  # Nokogiri adds a "default" doctype to the DOM, which we will remove
  dom.internal_subset.remove unless dom.internal_subset.nil?
  dom.create_internal_subset 'html', nil, nil
end

def ensure_head_element_present

def ensure_head_element_present
  if (head = dom.at_xpath('html/head'))
    head
  else
    create_head_element dom.at_xpath('html')
  end
end

def ensure_html_element_present

def ensure_html_element_present
  return if dom.at_xpath('html')
  html = Nokogiri::XML::Node.new 'html', dom
  dom << html
end

def improve

Returns:

(nil) - passed DOM will be mutated

def improve
  ensure_doctype_present
  ensure_html_element_present
  head = ensure_head_element_present
  ensure_declared_charset head
end

def initialize(dom, original_html)

determine if we want to add a HTML5 doctype or not.
the original source had it or not. Reading the raw HTML is the only way to
since a +Nokogiri::HTML::Document+ will always have a doctype, no matter if
The original HTML must also be passed in in order to handle the doctypes

def initialize(dom, original_html)
  @dom = dom
  @html = original_html
end

def make_content_type_element

def make_content_type_element
  meta = Nokogiri::XML::Node.new('meta', dom)
  meta['http-equiv'] = 'Content-Type'
  meta['content'] = 'text/html; charset=UTF-8'
  meta
end

def uses_buggy_jruby?

See https://github.com/sparklemotion/nokogiri/issues/984
JRuby up to at least 1.6.0 has a bug where the doctype of a document cannot be changed.

def uses_buggy_jruby?
  # No reason to check for version yet since no existing version has a fix.
  defined?(JRuby)
end

Modules

Classes