Class: Premailer

Inherits:
Object
  • Object
show all
Includes:
CssParser, HtmlToPlainText, Warnings
Defined in:
lib/premailer/adapter.rb,
lib/premailer/version.rb,
lib/premailer/premailer.rb,
lib/premailer/adapter/nokogiri.rb,
lib/premailer/adapter/nokogumbo.rb,
lib/premailer/adapter/nokogiri_fast.rb

Defined Under Namespace

Modules: Adapter, Warnings

Constant Summary collapse

VERSION =

Premailer version.

'1.14.2'.freeze
CLIENT_SUPPORT_FILE =
File.dirname(__FILE__) + '/../../misc/client_support.yaml'
RE_UNMERGABLE_SELECTORS =

Unmergable selectors regexp.

/(\:(visited|active|hover|focus|after|before|selection|target|first\-(line|letter))|^\@)/i
RE_RESET_SELECTORS =

Reset selectors regexp.

/^(\:\#outlook|body.*|\.ReadMsgBody|\.ExternalClass|img|\#backgroundTable)$/
HTML_ENTITIES =
{
  "’" => "'",
  "…" => "...",
  "‘" => "'",
  "‚" => ',',
  "‛" => "'",
  "“" => '"',
  "”" => '"',
  "‐" => '-',
  "–" => '-',
  "—" => '--',
  "―" => '--'
}
{
  'h1' => {'text-align' => 'align'},
  'h2' => {'text-align' => 'align'},
  'h3' => {'text-align' => 'align'},
  'h4' => {'text-align' => 'align'},
  'h5' => {'text-align' => 'align'},
  'h6' => {'text-align' => 'align'},
  'p' => {'text-align' => 'align'},
  'div' => {'text-align' => 'align'},
  'blockquote' => {'text-align' => 'align'},
  'body' => {'background-color' => 'bgcolor'},
  'table' => {
    '-premailer-align' => 'align',
    'background-color' => 'bgcolor',
    'background-image' => 'background',
    '-premailer-width' => 'width',
    '-premailer-height' => 'height',
    '-premailer-cellpadding' => 'cellpadding',
    '-premailer-cellspacing' => 'cellspacing'
  },
  'tr' => {
    'text-align' => 'align',
    'background-color' => 'bgcolor',
    '-premailer-height' => 'height'
  },
  'th' => {
    'text-align' => 'align',
    'background-color' => 'bgcolor',
    'vertical-align' => 'valign',
    '-premailer-width' => 'width',
    '-premailer-height' => 'height'
  },
  'td' => {
    'text-align' => 'align',
    'background-color' => 'bgcolor',
    'vertical-align' => 'valign',
    '-premailer-width' => 'width',
    '-premailer-height' => 'height'
  },
  'img' => {
    'float' => 'align',
    '-premailer-width' => 'width',
    '-premailer-height' => 'height'
  }
}
WARN_LABEL =

Waning level names

%w(NONE SAFE POOR RISKY)

Constants included from Warnings

Warnings::NONE, Warnings::POOR, Warnings::RISKY, Warnings::SAFE

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from HtmlToPlainText

#convert_to_text, #word_wrap

Constructor Details

#initialize(html, options = {}) ⇒ Premailer

Create a new Premailer object.

Parameters:

  • html

    is the HTML data to process. It can be either an IO object, the URL of a remote file, a local path or a raw HTML string. If passing an HTML string you must set the with_html_string option to true.

  • options (Hash) (defaults to: {})

    the options to handle html with.

Options Hash (options):

  • :line_length (Fixnum)

    Line length used by to_plain_text. Default is 65.

  • :warn_level (Fixnum)

    What level of CSS compatibility warnings to show (see Warnings, default is Warnings::SAFE).

  • :link_query_string (String)

    A string to append to every a href="" link. Do not include the initial ?.

  • :base_url (String)

    Used to calculate absolute URLs for local files.

  • :css (Array(String))

    Manually specify CSS stylesheets.

  • :css_to_attributes (Boolean)

    Copy related CSS attributes into HTML attributes (e.g. background-color to bgcolor). Default is true.

  • :preserve_style_attribute (Boolean)

    Preserve original style attribute

  • :css_string (String)

    Pass CSS as a string

  • :rgb_to_hex_attributes (Boolean)

    Convert RBG to Hex colors. Default is false.

  • :remove_ids (Boolean)

    Remove ID attributes whenever possible and convert IDs used as anchors to hashed to avoid collisions in webmail programs. Default is false.

  • :remove_classes (Boolean)

    Remove class attributes. Default is false.

  • :remove_comments (Boolean)

    Remove html comments. Default is false.

  • :remove_scripts (Boolean)

    Remove script elements. Default is true.

  • :reset_contenteditable (Boolean)

    Remove contenteditable attributes. Default is true.

  • :preserve_styles (Boolean)

    Whether to preserve any link rel=stylesheet and style elements. Default is false.

  • :preserve_reset (Boolean)

    Whether to preserve styles associated with the MailChimp reset code. Default is true.

  • :with_html_string (Boolean)

    Whether the html param should be treated as a raw string. Default is false.

  • :verbose (Boolean)

    Whether to print errors and warnings to $stderr. Default is false.

  • :io_exceptions (Boolean)

    Throws exceptions on I/O errors.

  • :include_link_tags (Boolean)

    Whether to include css from link rel=stylesheet tags. Default is true.

  • :include_style_tags (Boolean)

    Whether to include css from style tags. Default is true.

  • :input_encoding (String)

    Manually specify the source documents encoding. This is a good idea. Default is ASCII-8BIT.

  • :replace_html_entities (Boolean)

    Convert HTML entities to actual characters. Default is false.

  • :escape_url_attributes (Boolean)

    URL Escapes href, src, and background attributes on elements. Default is true.

  • :adapter (Symbol)

    Which HTML parser to use, :nokogiri, :nokogiri_fast or :nokogumbo. Default is :nokogiri.

  • :output_encoding (String)

    Output encoding option for Nokogiri adapter. Should be set to “US-ASCII” to output HTML entities instead of Unicode characters.

  • :create_shorthands (Boolean)

    Combine several properties into a shorthand one, e.g. font: style weight size. Default is true.

  • :html_fragment (Boolean)

    Handle HTML fragment without any HTML content wrappers. Default is false.

  • :drop_unmergeable_css_rules (Boolean)

    Do not include unmergeable css rules in a <tt><style><tt> tag. Default is false.


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# File 'lib/premailer/premailer.rb', line 182

def initialize(html, options = {})
  @options = {:warn_level => Warnings::SAFE,
              :line_length => 65,
              :link_query_string => nil,
              :base_url => nil,
              :rgb_to_hex_attributes => true,
              :remove_classes => false,
              :remove_ids => false,
              :remove_comments => false,
              :remove_scripts => true,
              :reset_contenteditable => true,
              :css => [],
              :css_to_attributes => true,
              :preserve_style_attribute => false,
              :with_html_string => false,
              :css_string => nil,
              :preserve_styles => false,
              :preserve_reset => true,
              :verbose => false,
              :debug => false,
              :io_exceptions => false,
              :include_link_tags => true,
              :include_style_tags => true,
              :input_encoding => 'ASCII-8BIT',
              :output_encoding => nil,
              :replace_html_entities => false,
              :escape_url_attributes => true,
              :unescaped_ampersand => false,
              :create_shorthands => true,
              :html_fragment => false,
              :adapter => Adapter.use,
              :drop_unmergeable_css_rules => false
              }.merge(options)

  @html_file = html
  @is_local_file = @options[:with_html_string] || Premailer.local_data?(html)

  @css_files = [@options[:css]].flatten

  @css_warnings = []

  @base_url = nil
  @base_dir = nil
  @unmergable_rules = nil

  if @options[:base_url]
    @base_url = Addressable::URI.parse(@options.delete(:base_url))
  elsif not @is_local_file
    @base_url = Addressable::URI.parse(@html_file)
  end

  @css_parser = CssParser::Parser.new({
    :absolute_paths => true,
    :import => true,
    :io_exceptions => @options[:io_exceptions]
  })

  @adapter_class = Adapter.find @options[:adapter]

  self.extend(@adapter_class)

  @doc = load_html(@html_file)

  @processed_doc = @doc
  @processed_doc = convert_inline_links(@processed_doc, @base_url) if @base_url
  if options[:link_query_string]
    @processed_doc = append_query_string(@processed_doc, options[:link_query_string])
  end
  load_css_from_options!
  load_css_from_html!
end

Instance Attribute Details

#base_dirString (readonly)

base directory used to resolve links for local files

Returns:

  • (String)

    base directory


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# File 'lib/premailer/premailer.rb', line 119

def base_dir
  @base_dir
end

#base_urlObject (readonly)

base URL used to resolve links


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# File 'lib/premailer/premailer.rb', line 115

def base_url
  @base_url
end

#docObject (readonly)

source HTML document (Nokogiri/Nokogumbo)


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# File 'lib/premailer/premailer.rb', line 128

def doc
  @doc
end

#html_fileObject (readonly)

URI of the HTML file used


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# File 'lib/premailer/premailer.rb', line 112

def html_file
  @html_file
end

#processed_docObject (readonly)

processed HTML document (Nokogiri/Nokogumbo)


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# File 'lib/premailer/premailer.rb', line 125

def processed_doc
  @processed_doc
end

#unmergable_rulesObject (readonly)

unmergeable CSS rules to be preserved in the head (CssParser)


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# File 'lib/premailer/premailer.rb', line 122

def unmergable_rules
  @unmergable_rules
end

Class Method Details

.canonicalize(uri) ⇒ Object


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# File 'lib/premailer/premailer.rb', line 499

def self.canonicalize(uri) # :nodoc:
u = uri.kind_of?(Addressable::URI) ? uri : Addressable::URI.parse(uri.to_s)
u.normalize!
newpath = u.path
while newpath.gsub!(%r{([^/]+)/\.\./?}) { |match|
    $1 == '..' ? match : ''
  } do end
  newpath = newpath.gsub(%r{/\./}, '/').sub(%r{/\.\z}, '/')
  u.path = newpath
  u.to_s
end

.is_media_query?(media_types) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/premailer/premailer.rb', line 467

def self.is_media_query?(media_types)
  media_types && media_types.any?{|mt| mt.to_s.count('()') >= 2 }
end

.local_data?(data) ⇒ Boolean

Test the passed variable to see if we are in local or remote mode.

IO objects return true, as do strings that look like URLs.

Returns:

  • (Boolean)

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# File 'lib/premailer/premailer.rb', line 493

def self.local_data?(data)
  return false  if data.kind_of?(String) && data =~ /\A(?:(https?|ftp):)\/\//i
  true
end

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# File 'lib/premailer/premailer.rb', line 472

def self.resolve_link(path, base_path) # :nodoc:
  path.strip!
  resolved = nil
  if path =~ /\A(?:(https?|ftp|file):)\/\//i
    resolved = path
    Premailer.canonicalize(resolved)
  elsif base_path.kind_of?(Addressable::URI)
    resolved = base_path.join(path)
    Premailer.canonicalize(resolved)
  elsif base_path.kind_of?(String) and base_path =~ /\A(?:(?:https?|ftp|file):)\/\//i
    resolved = Addressable::URI.parse(base_path)
    resolved = resolved.join(path)
    Premailer.canonicalize(resolved)
  else
    File.expand_path(path, File.dirname(base_path))
  end
end

Instance Method Details

#append_query_string(doc, qs) ⇒ Object


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# File 'lib/premailer/premailer.rb', line 355

def append_query_string(doc, qs)
  return doc if qs.nil?

  qs.to_s.gsub!(/^[\?]*/, '').strip!
  return doc if qs.empty?

  begin
    current_host = @base_url.host
  rescue
    current_host = nil
  end

  $stderr.puts "Attempting to append_query_string: #{qs}" if @options[:verbose]

  doc.search('a').each do|el|
    href = el.attributes['href'].to_s.strip
    next if href.nil? or href.empty?

    next if href[0,1] =~ /[\#\{\[\<\%]/ # don't bother with anchors or special-looking links

    begin
      href = Addressable::URI.parse(href)

      if current_host and href.host != nil and href.host != current_host
        $stderr.puts "Skipping append_query_string for: #{href.to_s} because host is no good" if @options[:verbose]
        next
      end

      if href.scheme and href.scheme != 'http' and href.scheme != 'https'
        puts "Skipping append_query_string for: #{href.to_s} because scheme is no good" if @options[:verbose]
        next
      end

      if href.query and not href.query.empty?
        amp = @options[:unescaped_ampersand] ? '&' : '&amp;'
        href.query = href.query + amp + qs
      else
        href.query = qs
      end

      el['href'] = href.to_s
    rescue Addressable::URI::InvalidURIError => e
      $stderr.puts "Skipping append_query_string for: #{href.to_s} (#{e.message})" if @options[:verbose]
      next
    end

  end
  doc
end

#check_client_supportObject

Check CLIENT_SUPPORT_FILE for any CSS warnings


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# File 'lib/premailer/premailer.rb', line 512

def check_client_support # :nodoc:
  @client_support ||= YAML::load(File.open(CLIENT_SUPPORT_FILE))

  warnings = []
  properties = []

  # Get a list off CSS properties
  @processed_doc.search("*[@style]").each do |el|
    style_url = el.attributes['style'].to_s.gsub(/([\w\-]+)[\s]*\:/i) do |s|
      properties.push($1)
    end
  end

  properties.uniq!

  property_support = @client_support['css_properties']
  properties.each do |prop|
    if property_support.include?(prop) and
        property_support[prop].include?('support') and
        property_support[prop]['support'] >= @options[:warn_level]
      warnings.push({:message => "#{prop} CSS property",
          :level => WARN_LABEL[property_support[prop]['support']],
          :clients => property_support[prop]['unsupported_in'].join(', ')})
    end
  end

  @client_support['attributes'].each do |attribute, data|
    next unless data['support'] >= @options[:warn_level]
    if @doc.search("*[@#{attribute}]").length > 0
      warnings.push({:message => "#{attribute} HTML attribute",
          :level => WARN_LABEL[data['support']],
          :clients => data['unsupported_in'].join(', ')})
    end
  end

  @client_support['elements'].each do |element, data|
    next unless data['support'] >= @options[:warn_level]
    if @doc.search(element).length > 0
      warnings.push({:message => "#{element} HTML element",
          :level => WARN_LABEL[data['support']],
          :clients => data['unsupported_in'].join(', ')})
    end
  end

  warnings
end

Convert relative links to absolute links.

Processes href src and background attributes as well as CSS url() declarations found in inline style attributes.

doc is a document and base_uri is either a string or a URI.

Returns a document.


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# File 'lib/premailer/premailer.rb', line 421

def convert_inline_links(doc, base_uri) # :nodoc:
  base_uri = Addressable::URI.parse(base_uri) unless base_uri.kind_of?(Addressable::URI)

  append_qs = @options[:link_query_string] || ''
  escape_attrs = @options[:escape_url_attributes]

  ['href', 'src', 'background'].each do |attribute|
    tags = doc.search("*[@#{attribute}]")

    next if tags.empty?

    tags.each do |tag|
      # skip links that look like they have merge tags
      # and mailto, ftp, etc...
      if tag.attributes[attribute].to_s =~ /^([\%\<\{\#\[]|data:|tel:|file:|sms:|callto:|facetime:|mailto:|ftp:|gopher:|cid:)/i
        next
      end

      if tag.attributes[attribute].to_s =~ /^http/i
        begin
          merged = Addressable::URI.parse(tag.attributes[attribute])
        rescue; next; end
      else
        begin
          merged = Premailer.resolve_link(tag.attributes[attribute].to_s, base_uri)
        rescue
          begin
            next unless escape_attrs
            merged = Premailer.resolve_link(Addressable::URI.escape(tag.attributes[attribute].to_s), base_uri)
          rescue; end
        end
      end

      # make sure 'merged' is a URI
      merged = Addressable::URI.parse(merged.to_s) unless merged.kind_of?(Addressable::URI)
      tag[attribute] = merged.to_s
    end # end of each tag
  end # end of each attrs

  doc.search("*[@style]").each do |el|
    el['style'] = CssParser.convert_uris(el.attributes['style'].to_s, base_uri)
  end
  doc
end

#is_xhtml?Boolean

Check for an XHTML doctype

Returns:

  • (Boolean)

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# File 'lib/premailer/premailer.rb', line 406

def is_xhtml?
  intro = @doc.to_xhtml.strip.split("\n")[0..2].join(' ')
  is_xhtml = !!(intro =~ /w3c\/\/[\s]*dtd[\s]+xhtml/i)
  $stderr.puts "Is XHTML? #{is_xhtml.inspect}\nChecked:\n#{intro}" if @options[:debug]
  is_xhtml
end

#local_uri?(uri) ⇒ Boolean

Deprecated.

Returns:

  • (Boolean)

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# File 'lib/premailer/premailer.rb', line 341

def local_uri?(uri) # :nodoc:
  warn "[DEPRECATION] `local_uri?` is deprecated.  Please use `Premailer.local_data?` instead."
  Premailer.local_data?(uri)
end

#media_type_ok?(media_types) ⇒ Boolean

Returns:

  • (Boolean)

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# File 'lib/premailer/premailer.rb', line 349

def media_type_ok?(media_types)
  media_types = media_types.to_s
  return true if media_types.nil? or media_types.empty?
  media_types.split(/[\s]+|,/).any? { |media_type| media_type.strip =~ /screen|handheld|all/i }
end

#warningsArray(Hash)

CSS warnings.

Returns:

  • (Array(Hash))

    Array of warnings.


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# File 'lib/premailer/premailer.rb', line 256

def warnings
  return [] if @options[:warn_level] == Warnings::NONE
  @css_warnings = check_client_support if @css_warnings.empty?
  @css_warnings
end