The SanitizeHelper module provides a set of methods for scrubbing text of undesired HTML elements. These helper methods extend Action View making them callable within your template files.
Sanitizes HTML input, stripping all tags and attributes that aren't whitelisted.
It also strips href/src attributes with unsafe protocols like
javascript:
, while also protecting against attempts to use
Unicode, ASCII, and hex character references to work around these protocol
filters. All special characters will be escaped.
The default sanitizer is Rails::Html::WhiteListSanitizer. See Rails HTML Sanitizers for more information.
Custom sanitization rules can also be provided.
Please note that sanitizing user-provided text does not guarantee that the resulting markup is valid or even well-formed.
Options
-
:tags
- An array of allowed tags. -
:attributes
- An array of allowed attributes. -
:scrubber
- A Rails::Html scrubber or Loofah::Scrubber object that defines custom sanitization rules. A custom scrubber takes precedence over custom tags and attributes.
Examples
Normal use:
<%= sanitize @comment.body %>
Providing custom whitelisted tags and attributes:
<%= sanitize @comment.body, tags: %w(strong em a), attributes: %w(href) %>
Providing a custom Rails::Html scrubber:
class CommentScrubber < Rails::Html::PermitScrubber
def initialize
super
self.tags = %w( form script comment blockquote )
self.attributes = %w( style )
end
def skip_node?(node)
node.text?
end
end
<%= sanitize @comment.body, scrubber: CommentScrubber.new %>
See Rails HTML Sanitizer for documentation about Rails::Html scrubbers.
Providing a custom Loofah::Scrubber:
scrubber = Loofah::Scrubber.new do |node|
node.remove if node.name == 'script'
end
<%= sanitize @comment.body, scrubber: scrubber %>
See Loofah’s documentation for more information about defining custom Loofah::Scrubber objects.
To set the default allowed tags or attributes across your application:
# In config/application.rb
config.action_view.sanitized_allowed_tags = ['strong', 'em', 'a']
config.action_view.sanitized_allowed_attributes = ['href', 'title']
Sanitizes a block of CSS code. Used by sanitize
when it comes
across a style attribute.
Strips all link tags from html
leaving just the link text.
strip_links('<a href="http://www.rubyonrails.org">Ruby on Rails</a>')
# => Ruby on Rails
strip_links('Please e-mail me at <a href="mailto:me@email.com">me@email.com</a>.')
# => Please e-mail me at me@email.com.
strip_links('Blog: <a href="http://www.myblog.com/" class="nav" target=\"_blank\">Visit</a>.')
# => Blog: Visit.
strip_links('<<a href="https://example.org">malformed & link</a>')
# => <malformed & link
Strips all HTML tags from html
, including comments and special
characters.
strip_tags("Strip <i>these</i> tags!")
# => Strip these tags!
strip_tags("<b>Bold</b> no more! <a href='more.html'>See more here</a>...")
# => Bold no more! See more here...
strip_tags("<div id='top-bar'>Welcome to my website!</div>")
# => Welcome to my website!
strip_tags("> A quote from Smith & Wesson")
# => > A quote from Smith & Wesson