Redcarpet markdown ignoring multiple line breaks

Question

I have user-entered markdown text stored in a database that I need to render with a custom Redcarpet renderer (for Prawn PDF generation). For single line breaks (i.e. "\r\n"), the renderer correctly processes the break. However, when the text contains multiple line breaks in a row (i.e. "\r\n\r\n") the markdown renderer removes and ignores them.

Also, the linebreak method is never called in my custom renderer while the paragraph and emphasis methods are.

Example ruby script:

require 'redcarpet'

class TestRenderer < Redcarpet::Render::Base
  def paragraph(text)
    text
  end
  def emphasis(text)
    '<foo>' + text + '</foo>'
  end
  def linebreak
    '<should this be called?>'
  end
end

def markdown_this(content)
  markdown = Redcarpet::Markdown.new(TestRenderer)
  markdown.render(content.to_s)
end

s = '_testing_\r\nthat\r\nthis\r\n\r\nline\r\n\r\n\r\nbreaks'
s_rn = s.gsub '\r\n', "\r\n"
s_n = s.gsub '\r\n', "\n"

puts "\n\n"
puts 'raw string -----------------------'
puts s

puts 'gsub \r\n string -----------------'
puts s_rn

puts 'gsub \n string -------------------'
puts s_n

puts 'markdown \r\n string -------------'
puts markdown_this(s_rn)

puts 'markdown \n string ---------------'
puts markdown_this(s_n)

puts '----------------------------------'
puts "\n\n"

Answer 1

Any number of line breaks (more than one) is considered a paragraph in markdown, so parser just eats the extra line breaks and it has nothing to do with a renderer.

You can inherit from HTML renderer to better understand how it works.

class TestRenderer < Redcarpet::Render::HTML

Also see this answer which has info on how to add multiple line breaks (maybe you can get away with just replacing "\r\n" with "\r\n " before rendering markdown)