Refactor how footnotes are handled

[stadelmanma]

Refactor how footnotes are handled

[stadelmanma]

I was able to implement this using configuration only in my branch live-2.0 which contains processor registration and a template DOM, only the DOM bit is actually needed. This doesn't do all that I talk about above since it relies on HTML to insert the references instead of allowing the option to insert a reference using regular insertion via a merge field in the document itself.

Code used is below:

module Sablon
  # Adding custom handler to DOM
  module DOM
    # Manages footnotes in the document
    class Footnotes < FileHandler
      #
      # extends the Model class so it now has an "add_footnote" method.
      def self.extend_model(model_klass)
        super do
          #
          # adds a footnote to the file and returns the id
          define_method(:add_footnote) do |env, content|
            @dom['word/footnotes.xml'].add_footnote(env, content)
          end
        end
      end

      # sets up the class to add new footnotes
      def initialize(xml_node)
        super
        #
        @footnotes = xml_node.root
        @max_id = max_attribute_value(@footnotes, '//w:footnote', 'w:id')
      end

      # Add the footnote and return the id number used
      def add_footnote(env, content)
        # add the node to the document
        current_id = next_id
        new_node = @footnotes.add_child(footnote_tag(current_id))
        #
        # append the content to the footnote node
        paragraph = new_node.xpath('./w:p').last
        display_node = paragraph.at_xpath('.//w:t')
        content.append_to(paragraph, display_node, env)
        #
        # add in a reference tag
        new_node.xpath('.//w:r').first.add_previous_sibling(footnote_ref_tag)
        #
        current_id
      end

      private

      # Increments the ID and returns it
      def next_id
        @max_id += 1
      end

      # This generates the proper footnote tag by injecting the content
      # into it.
      def footnote_tag(id)
        <<-XML.gsub(/^\s*|\n/, '')
          <w:footnote w:id="#{id}">
            <w:p>
              <w:pPr>
                <w:pStyle w:val="FootnoteText"/>
              </w:pPr>
              <w:r>
                <w:t xml:space="preserve">Replace Me!</w:t>
              </w:r>
            </w:p>
          </w:footnote>
        XML
      end

      # generates the reference tag which shows the number in the
      # bottom of the page by the footnote.
      def footnote_ref_tag
        <<-XML.gsub(/^\s*|\n/, '')
          <w:r>
            <w:rPr>
              <w:rStyle w:val="FootnoteReference"/>
            </w:rPr>
            <w:footnoteRef/>
          </w:r>
        XML
      end
    end
    register_dom_handler(%r{word/footnotes.xml}, Sablon::DOM::Footnotes)
  end

  # Locally added content types
  module Content
    # Allows footnotes to be properly inserted into the document
    class Footnote
      include Sablon::Content
      def self.id
        :footnote
      end

      def self.wraps?(*)
        false
      end

      def initialize(options)
        type_id = options['content_type'].to_sym
        @content = Content.make(type_id, options['content'])
      end

      def append_to(*args)
        @content.append_to(*args)
      end
    end
    #
    register Sablon::Content::Footnote
  end

  # Locally added HTML AST classes
  class HTMLConverter
    # inserts a footnote refrence into the document
    class FootnoteReference < Run
      def initialize(env, node, properties)
        @properties = NodeProperties.run(properties)
        #
        # only works if footnotes aren't nested inside another hash
        name = node['placeholder']
        footnote_content = env.context[name]
        @footnote_id = env.document.add_footnote(env, footnote_content)
      end

      def inspect
        "<FootnoteReference{#{@properties.inspect}}: Id:#{@footnote_id}>"
      end

      private

      def children_to_docx
        "<w:footnoteReference w:id=\"#{@footnote_id}\"/>"
      end
    end
  end
end