Class: GovukTechDocs::TechDocsHTMLRenderer

Inherits:
Middleman::Renderers::MiddlemanRedcarpetHTML
  • Object
show all
Includes:
Redcarpet::Render::SmartyPants
Defined in:
lib/govuk_tech_docs/tech_docs_html_renderer.rb

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ TechDocsHTMLRenderer

Returns a new instance of TechDocsHTMLRenderer.



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 7

def initialize(options = {})
  @local_options = options.dup
  @app = @local_options[:context].app
  super
end

Instance Method Details

#block_code(text, lang) ⇒ Object 



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 82

def block_code(text, lang)
  if defined?(super)
    # Post-processing the block_code HTML to implement tabbable code blocks.
    #
    # Middleman monkey patches the Middleman::Renderers::MiddlemanRedcarpetHTML
    # to include Middleman::Syntax::RedcarpetCodeRenderer. This defines its own
    # version of `block_code(text, lang)` which we can call with `super`.

    fragment = Nokogiri::HTML::DocumentFragment.parse(super)
    fragment.traverse do |element|
      if element.name == "pre" && element["tabindex"].nil?
        element["tabindex"] = "0"
      end
    end
    fragment.to_html
  else
    # If syntax highlighting with redcarpet isn't enabled, super will not
    # be `defined?`, so we can jump straight to rendering HTML ourselves.

    fragment = Nokogiri::HTML::DocumentFragment.parse("")
    pre = Nokogiri::XML::Node.new "pre", fragment.document
    pre["tabindex"] = "0"
    code = Nokogiri::XML::Node.new "code", fragment.document
    code["class"] = lang
    code.content = text
    pre.add_child code
    pre.to_html
  end
end

#header(text, level) ⇒ Object 



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 17

def header(text, level)
  anchor = UniqueIdentifierGenerator.instance.create(text, level)
  %(<h#{level} id="#{anchor}">#{text}</h#{level}>\n)
end

#image(link, title, alt_text) ⇒ Object 



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 22

def image(link, title, alt_text)
  if alt_text && !alt_text.strip.empty?
    %(<a href="#{link}" rel="noopener noreferrer">#{super}</a>)
  else
    super
  end
end

#paragraph(text) ⇒ Object 



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 13

def paragraph(text)
  @app.api("<p>#{text.strip}</p>\n")
end

#table(header, body) ⇒ Object 



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 30

def table(header, body)
  %(<div class="table-container">
    <table>
      #{header}#{body}
    </table>
  </div>)
end

#table_row(body) ⇒ Object 



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# File 'lib/govuk_tech_docs/tech_docs_html_renderer.rb', line 38

def table_row(body)
  # Post-processing the table_cell HTML to implement row headings.
  #
  # Doing this in table_row instead of table_cell is a hack.
  #
  # Ideally, we'd use the table_cell callback like:
  #
  # def table_cell(content, alignment, header)
  #   if header
  #     "<th>#{content}</th>"
  #   elsif content.start_with? "# "
  #     "<th scope="row">#{content.sub(/^# /, "")}</th>"
  #   else
  #     "<td>#{content}</td>"
  #   end
  # end
  #
  # Sadly, Redcarpet's table_cell callback doesn't allow you to distinguish
  # table cells and table headings until https://github.com/vmg/redcarpet/commit/27dfb2a738a23aadd286ac9e7ecd61c4545d29de
  # (which is not yet released). This means we can't use the table_cell callback
  # without breaking column headers, so we're having to hack it in table_row.

  fragment = Nokogiri::HTML::DocumentFragment.parse(body)
  fragment.children.each do |cell|
    next unless cell.name == "td"
    next if cell.children.empty?

    first_child = cell.children.first
    next unless first_child.text?

    leading_text = first_child.content
    next unless leading_text.start_with?("#")

    cell.name = "th"
    cell["scope"] = "row"
    first_child.content = leading_text.sub(/# */, "")
  end

  tr = Nokogiri::XML::Node.new "tr", fragment.document
  tr.children = fragment.children

  tr.to_html
end