Module: HTMLHelpers

Included in:
Mill::Resource::Feed, Mill::Resource::Image, Mill::Resource::Text
Defined in:
lib/mill/html_helpers.rb

Defined Under Namespace

Classes: HTMLError, PreText

Constant Summary collapse

IgnoreErrors = 
%Q{
  <table> lacks "summary" attribute
  <img> lacks "alt" attribute
  <form> proprietary attribute "novalidate"
  <input> attribute "type" has invalid value "email"
  <input> attribute "tabindex" has invalid value "-1"
}.split(/\n/).map(&:strip)

Instance Method Summary collapse

Instance Method Details

#amazon_button(asin) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 95

def amazon_button(asin)
  html_fragment do |html|
    html.a(href: "http://www.amazon.com/dp/#{asin}") do
      html.img(src: '/images/buy1._V46787834_.gif', alt: 'Buy from Amazon.com')
    end
  end
end

#google_analytics(tracker_id) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 129

def google_analytics(tracker_id)
  html_fragment do |html|
    html.script(type: 'text/javascript') do
      html << %Q{
        var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www.");
        document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E"));
      }
    end
    html.script(type: 'text/javascript') do
      html << %Q{
        try {
          var pageTracker = _gat._getTracker("#{tracker_id}");
          pageTracker._trackPageview();
        } catch(err) {}
      }
    end
  end
end

#html_document(&block) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 13

def html_document(&block)
  builder = Nokogiri::HTML::Builder.new(encoding: 'utf-8') do |doc|
    yield(doc)
  end
  builder.doc
end

#html_fragment(&block) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 20

def html_fragment(&block)
  html = Nokogiri::HTML::DocumentFragment.parse('')
  Nokogiri::HTML::Builder.with(html) do |html|
    yield(html)
  end
  html
end

#parse_html(str) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 28

def parse_html(str)
  html = Nokogiri::HTML::Document.parse(str) { |config| config.strict }
  html.errors.each do |error|
    next if error.message =~ /^Tag (.*?) invalid$/
    raise HTMLError, "HTML error at line #{error.line}, column #{error.column}: #{error.message}"
  end
  html
end

#parse_tidy_errors(tidy) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 75

def parse_tidy_errors(tidy)
  return [] unless tidy.errors
  tidy.errors.split(/\n/).map do |error_str|
    error_str =~ /^line (\d+) column (\d+) - (.*?): (.*)$/ or raise "Can't parse error: #{error_str}"
    {
      msg: error_str,
      line: $1.to_i - 1,
      column: $2.to_i - 1,
      type: $3.downcase.to_sym,
      error: $4.strip,
    }
  end
end

#paypal_button(id) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 103

def paypal_button(id)
  html_fragment do |html|
    html.form(action: 'https://www.paypal.com/cgi-bin/webscr', method: 'post') do
      html.input(
        type: 'hidden',
        name: 'cmd',
        value: '_s-xclick')
      html.input(
        type: 'hidden',
        name: 'hosted_button_id',
        value: id)
      html.input(
        type: 'image',
        src: 'https://www.paypalobjects.com/en_US/i/btn/btn_buynow_LG.gif',
        name: 'submit',
        alt: 'PayPal - The safer, easier way to pay online!')
      html.img(
        alt: '',
        border: 0,
        width: 1,
        height: 1,
        src: 'https://www.paypalobjects.com/en_US/i/scr/pixel.gif')
    end
  end
end

#replace_element(html, xpath, &block) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 89

def replace_element(html, xpath, &block)
  html.xpath(xpath).each do |elem|
    elem.replace(yield(elem))
  end
end

#tidy_html(html, &block) ⇒ Object 



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# File 'lib/mill/html_helpers.rb', line 37

def tidy_html(html, &block)
  html_str = html.to_s
  tidy = TidyFFI::Tidy.new(html_str, char_encoding: 'UTF8')
  errors = parse_tidy_errors(tidy).reject do |error|
    IgnoreErrors.include?(error[:error])
  end
  unless errors.empty?
    full_error = StringIO.new('')
    full_error.puts "invalid HTML:"
    html_lines = html_str.split(/\n/)
    errors.each do |error|
      full_error.puts "\t#{error[:msg]}:"
      html_lines.each_with_index do |html_line, i|
        if i >= [0, error[:line] - 2].max && i <= [error[:line] + 2, html_lines.length].min
          if i == error[:line]
            output = [
              error[:column] > 0 ? (html_line[0 .. error[:column] - 1]) : '',
              Term::ANSIColor.negative,
              html_line[error[:column]],
              Term::ANSIColor.clear,
              html_line[error[:column] + 1 .. -1],
            ]
          else
            output = [html_line]
          end
          full_error.puts "\t\t%3s: %s" % [i + 1, output.join]
        end
      end
      if block_given?
        yield(full_error.string)
      else
        STDERR.print(full_error.string)
      end
      raise HTMLError, "HTML error: #{error[:msg]}" if error[:type] == :error
    end
  end
end