Module: Locomotivecms::Freight::HtmlToMarkdown

Defined in:
lib/locomotivecms/freight/html_to_markdown.rb

Class Method Summary collapse

Class Method Details

.convert_bold(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 27

def convert_bold html
  html \
    .gsub(/\<(b .*?>|b>|strong.*?>)[\n\s]*/i, '**')
    .gsub(/[\n\s]*\<(\/b|\/strong)[^\>]*\>/i, '**')
end

.convert_headings(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 71

def convert_headings html
  html.gsub(/\<h\d.*?\>.*?\<\/h\d\>/mi) { |heading|
    match = heading.match /\<h(\d).*?\>(.*?)\<\/h\d\>/mi
    heading_prefix = "#" * match[1].to_i
    heading_text = match[2].gsub(/\n/, ' ').gsub(/^\s*/, '').gsub(/\s*$/, '')
    "#{heading_prefix} #{heading_text}"
  }
end

.convert_images(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 102

def convert_images html
  html = html.dup
  images = {}
  html.gsub!(/<img.*?\/?>/mi) { |img|
    index = images.length
    src_match = img.match /<img.*?src=["']?([^\s"']+)["']?.*?\/?>/mi
    return img unless src_match.present?
    src = src_match[1]
    alt_match = img.match /<img.*?alt=["']([^"']+)["'].*?\/?>/mi
    alt = alt_match[1] if alt_match.present?
    title_match = img.match /<img.*?title=["']([^"']+)["'].*?\/?>/mi
    title = title_match[1] if title_match.present?
    if alt.blank?
      if title.present?
        alt = title
      else
        alt = src.gsub(/^.*\//,'').gsub(/\..*$/,'')
      end
    elsif title.blank?
      title = alt
    end
    title = title.present? ? " \"#{title}\"" : nil
    index = "img-#{(images.size + 1).to_s.rjust(2, '0')}"
    images[index] = OpenStruct.new({ url: src, title: title })
    "![#{alt}][#{index}]"
  }
  html << "\n"
  html << images.each_pair.map do |index, img|
    "[#{index}]: #{img.url}#{img.title}"
  end.join("\n")
  html << "\n"
end

.convert_italics(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 21

def convert_italics html
  html \
    .gsub(/<(i .*?>|i>|em.*?>)[\n\s]*/i, '_')
    .gsub(/[\n\s]*\<(\/i|\/em)[^\>]*\>/i, '_')
end

.convert_links(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 80

def convert_links html
  html = html.dup
  urls = []
  html.gsub!(/\<a.*?\>.*?\<\/a\>/mi) { |link|
    index = urls.length
    match = link.match /\<a.*href=["']?([^\s"']+)["']?.*\>(.*?)\<\/a\>/mi
    if match.nil?
      raise "No match for link: #{link}"
    end
    link_href = match[1]
    link_text = match[2]
    urls[index] = link_href
    "[#{link_text}][#{index + 1}]"
  }
  html << "\n"
  html << urls.each_with_index.map do |url, i|
    index = i + 1
    "[#{index}]: #{url}"
  end.join("\n")
  html << "\n"
end

.convert_paragraphs(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 60

def convert_paragraphs html
  if html.match(/<\/?p\s?.*?>/)
    html = html.dup \
      .split(/[\s\n]*\<\/{0,1}p.*?\>[\s\n]*/i)
      .reject{|chunk| chunk.match /^[\s\n]*$/ }
      .join("\n\n")
      .chomp + "\n"
  end
  html
end

.convert_preformatted(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 33

def convert_preformatted html
  html.gsub(/<pre.*?>.*?<\/pre.*?>/m) do |pre|
    text = pre.match(/<pre.*?>(.*?)<\/pre.*?>/m)[1]
    text \
      .strip
      .split(/\n\n/m)
      .map do |para|
        para.split(/\n/).join("<br />\n")
      end \
      .join("\n\n")
      .chomp
  end.gsub(/\n\n\n/, "\n\n")
end

.convert_tables(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 47

def convert_tables html
  html.gsub(/\s*<table.*?>.*?<\/table>/mi) do |table|
    markdown = "\n\n|"
    table.scan(/<tr.*?>.*?<\/tr>/mi) do |row|
      row.scan(/<td.*?>.*?<\/td>/mi) do |cell|
        markdown << cell.gsub(/^<td.*?>/mi, '').gsub(/<\/td>$/mi, '')
        markdown << "|"
      end
    end
    markdown << "\n"
  end
end

.convert_to_markdown(html) ⇒ Object 



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# File 'lib/locomotivecms/freight/html_to_markdown.rb', line 9

def convert_to_markdown html
  html = convert_italics html
  html = convert_bold html
  html = convert_tables html
  html = convert_preformatted html
  html = convert_paragraphs html
  html = convert_headings html
  html = convert_images html
  html = convert_links html
  html
end