class Rails::Html::WhiteListSanitizer

Rails::Html::WhiteListSanitizer

Sanitizes html and css from an extensive white list (see link further down).

Whitespace

We can't make any guarentees about whitespace being kept or stripped. Loofah uses Nokogiri, which wraps either a C or Java parser for the respective Ruby implementation. Those two parsers determine how whitespace is ultimately handled.

When the stripped markup will be rendered the users browser won't take whitespace into account anyway. It might be better to suggest your users wrap their whitespace sensitive content in pre tags or that you do so automatically.

Options

Sanitizes both html and css via the white lists found here: github.com/flavorjones/loofah/blob/master/lib/loofah/html5/whitelist.rb

WhiteListSanitizer also accepts options to configure the white list used when sanitizing html. There's a class level option: #allowed_tags = %w(table tr td) #allowed_attributes = %w(id class style)

Tags and attributes can also be passed to sanitize. Passed options take precedence over the class level options.

Examples

white_list_sanitizer = ::new

Sanitize css doesn't take options white_list_sanitizer.sanitize_css('background-color: #000;')

Default: sanitize via a extensive white list of allowed elements white_list_sanitizer.sanitize(@article.body)

White list via the supplied tags and attributes white_list_sanitizer.sanitize(@article.body, tags: %w(table tr td), attributes: %w(id class style))

White list via a custom scrubber white_list_sanitizer.sanitize(@article.body, scrubber: ArticleScrubber.new)

Attributes

allowed_attributes[RW]
allowed_tags[RW]

Public Class Methods

new() click to toggle source
# File lib/rails/html/sanitizer.rb, line 112
def initialize
  @permit_scrubber = PermitScrubber.new
end

Public Instance Methods

sanitize(html, options = {}) click to toggle source
# File lib/rails/html/sanitizer.rb, line 116
def sanitize(html, options = {})
  return unless html
  return html if html.empty?

  loofah_fragment = Loofah.fragment(html)

  if scrubber = options[:scrubber]
    # No duck typing, Loofah ensures subclass of Loofah::Scrubber
    loofah_fragment.scrub!(scrubber)
  elsif allowed_tags(options) || allowed_attributes(options)
    @permit_scrubber.tags = allowed_tags(options)
    @permit_scrubber.attributes = allowed_attributes(options)
    loofah_fragment.scrub!(@permit_scrubber)
  else
    remove_xpaths(loofah_fragment, XPATHS_TO_REMOVE)
    loofah_fragment.scrub!(:strip)
  end

  loofah_fragment.to_s
end
sanitize_css(style_string) click to toggle source
# File lib/rails/html/sanitizer.rb, line 137
def sanitize_css(style_string)
  Loofah::HTML5::Scrub.scrub_css(style_string)
end

Private Instance Methods

allowed_attributes(options) click to toggle source
# File lib/rails/html/sanitizer.rb, line 147
def allowed_attributes(options)
  options[:attributes] || self.class.allowed_attributes
end
allowed_tags(options) click to toggle source
# File lib/rails/html/sanitizer.rb, line 143
def allowed_tags(options)
  options[:tags] || self.class.allowed_tags
end