class Rails::Html::WhiteListSanitizer
Rails::Html::SafeListSanitizer
¶ ↑
Sanitizes html and css from an extensive safe list (see link further down).
Whitespace¶ ↑
We can't make any guarantees 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 safe lists found here: github.com/flavorjones/loofah/blob/master/lib/loofah/html5/safelist.rb
SafeListSanitizer
also accepts options to configure the safe list used when sanitizing html. There's a class level option: Rails::Html::SafeListSanitizer.allowed_tags
= %w(table tr td) Rails::Html::SafeListSanitizer.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¶ ↑
safe_list_sanitizer = Rails::Html::SafeListSanitizer.new
Sanitize css doesn't take options safe_list_sanitizer.sanitize_css('background-color: #000;')
Default: sanitize via a extensive safe list of allowed elements safe_list_sanitizer.sanitize(@article.body)
Safe list via the supplied tags and attributes safe_list_sanitizer.sanitize(@article.body, tags: %w(table tr td), attributes: %w(id class style))
Safe list via a custom scrubber safe_list_sanitizer.sanitize(@article.body, scrubber: ArticleScrubber.new)
Attributes
Public Class Methods
# File lib/rails/html/sanitizer.rb, line 113 def initialize @permit_scrubber = PermitScrubber.new end
Public Instance Methods
# File lib/rails/html/sanitizer.rb, line 117 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 properly_encode(loofah_fragment, encoding: 'UTF-8') end
# File lib/rails/html/sanitizer.rb, line 138 def sanitize_css(style_string) Loofah::HTML5::Scrub.scrub_css(style_string) end
Private Instance Methods
# File lib/rails/html/sanitizer.rb, line 148 def allowed_attributes(options) options[:attributes] || self.class.allowed_attributes end