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rails--rails/actionpack/lib/action_view/helpers/sanitize_helper.rb

260 lines
9.3 KiB
Ruby

require 'active_support/core_ext/object/try'
require 'action_controller/vendor/html-scanner'
require 'action_view/helpers/tag_helper'
module ActionView
# = Action View Sanitize Helpers
module Helpers #:nodoc:
# 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.
module SanitizeHelper
extend ActiveSupport::Concern
# This +sanitize+ helper will html encode all tags and strip all attributes that
# aren't specifically allowed.
#
# It also strips href/src tags with invalid protocols, like javascript: especially.
# It does its best to counter any tricks that hackers may use, like throwing in
# unicode/ascii/hex values to get past the javascript: filters. Check out
# the extensive test suite.
#
# <%= sanitize @article.body %>
#
# You can add or remove tags/attributes if you want to customize it a bit.
# See ActionView::Base for full docs on the available options. You can add
# tags/attributes for single uses of +sanitize+ by passing either the
# <tt>:attributes</tt> or <tt>:tags</tt> options:
#
# Normal Use
#
# <%= sanitize @article.body %>
#
# Custom Use (only the mentioned tags and attributes are allowed, nothing else)
#
# <%= sanitize @article.body, :tags => %w(table tr td), :attributes => %w(id class style) %>
#
# Add table tags to the default allowed tags
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td'
# end
#
# Remove tags to the default allowed tags
#
# class Application < Rails::Application
# config.after_initialize do
# ActionView::Base.sanitized_allowed_tags.delete 'div'
# end
# end
#
# Change allowed default attributes
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_attributes = 'id', 'class', 'style'
# end
#
# Please note that sanitizing user-provided text does not guarantee that the
# resulting markup is valid (conforming to a document type) or even well-formed.
# The output may still contain e.g. unescaped '<', '>', '&' characters and
# confuse browsers.
#
def sanitize(html, options = {})
self.class.white_list_sanitizer.sanitize(html, options).try(:html_safe)
end
# Sanitizes a block of CSS code. Used by +sanitize+ when it comes across a style attribute.
def sanitize_css(style)
self.class.white_list_sanitizer.sanitize_css(style)
end
# Strips all HTML tags from the +html+, including comments. This uses the
# html-scanner tokenizer and so its HTML parsing ability is limited by
# that of html-scanner.
#
# ==== Examples
#
# 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!
def strip_tags(html)
self.class.full_sanitizer.sanitize(html).try(:html_safe)
end
# Strips all link tags from +text+ leaving just the link text.
#
# ==== Examples
# 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
def strip_links(html)
self.class.link_sanitizer.sanitize(html)
end
module ClassMethods #:nodoc:
attr_writer :full_sanitizer, :link_sanitizer, :white_list_sanitizer
def sanitized_protocol_separator
white_list_sanitizer.protocol_separator
end
def sanitized_uri_attributes
white_list_sanitizer.uri_attributes
end
def sanitized_bad_tags
white_list_sanitizer.bad_tags
end
def sanitized_allowed_tags
white_list_sanitizer.allowed_tags
end
def sanitized_allowed_attributes
white_list_sanitizer.allowed_attributes
end
def sanitized_allowed_css_properties
white_list_sanitizer.allowed_css_properties
end
def sanitized_allowed_css_keywords
white_list_sanitizer.allowed_css_keywords
end
def sanitized_shorthand_css_properties
white_list_sanitizer.shorthand_css_properties
end
def sanitized_allowed_protocols
white_list_sanitizer.allowed_protocols
end
def sanitized_protocol_separator=(value)
white_list_sanitizer.protocol_separator = value
end
# Gets the HTML::FullSanitizer instance used by +strip_tags+. Replace with
# any object that responds to +sanitize+.
#
# class Application < Rails::Application
# config.action_view.full_sanitizer = MySpecialSanitizer.new
# end
#
def full_sanitizer
@full_sanitizer ||= HTML::FullSanitizer.new
end
# Gets the HTML::LinkSanitizer instance used by +strip_links+. Replace with
# any object that responds to +sanitize+.
#
# class Application < Rails::Application
# config.action_view.link_sanitizer = MySpecialSanitizer.new
# end
#
def link_sanitizer
@link_sanitizer ||= HTML::LinkSanitizer.new
end
# Gets the HTML::WhiteListSanitizer instance used by sanitize and +sanitize_css+.
# Replace with any object that responds to +sanitize+.
#
# class Application < Rails::Application
# config.action_view.white_list_sanitizer = MySpecialSanitizer.new
# end
#
def white_list_sanitizer
@white_list_sanitizer ||= HTML::WhiteListSanitizer.new
end
# Adds valid HTML attributes that the +sanitize+ helper checks for URIs.
#
# class Application < Rails::Application
# config.action_view.sanitized_uri_attributes = 'lowsrc', 'target'
# end
#
def sanitized_uri_attributes=(attributes)
HTML::WhiteListSanitizer.uri_attributes.merge(attributes)
end
# Adds to the Set of 'bad' tags for the +sanitize+ helper.
#
# class Application < Rails::Application
# config.action_view.sanitized_bad_tags = 'embed', 'object'
# end
#
def sanitized_bad_tags=(attributes)
HTML::WhiteListSanitizer.bad_tags.merge(attributes)
end
# Adds to the Set of allowed tags for the +sanitize+ helper.
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_tags = 'table', 'tr', 'td'
# end
#
def sanitized_allowed_tags=(attributes)
HTML::WhiteListSanitizer.allowed_tags.merge(attributes)
end
# Adds to the Set of allowed HTML attributes for the +sanitize+ helper.
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_attributes = 'onclick', 'longdesc'
# end
#
def sanitized_allowed_attributes=(attributes)
HTML::WhiteListSanitizer.allowed_attributes.merge(attributes)
end
# Adds to the Set of allowed CSS properties for the #sanitize and +sanitize_css+ helpers.
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_css_properties = 'expression'
# end
#
def sanitized_allowed_css_properties=(attributes)
HTML::WhiteListSanitizer.allowed_css_properties.merge(attributes)
end
# Adds to the Set of allowed CSS keywords for the +sanitize+ and +sanitize_css+ helpers.
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_css_keywords = 'expression'
# end
#
def sanitized_allowed_css_keywords=(attributes)
HTML::WhiteListSanitizer.allowed_css_keywords.merge(attributes)
end
# Adds to the Set of allowed shorthand CSS properties for the +sanitize+ and +sanitize_css+ helpers.
#
# class Application < Rails::Application
# config.action_view.sanitized_shorthand_css_properties = 'expression'
# end
#
def sanitized_shorthand_css_properties=(attributes)
HTML::WhiteListSanitizer.shorthand_css_properties.merge(attributes)
end
# Adds to the Set of allowed protocols for the +sanitize+ helper.
#
# class Application < Rails::Application
# config.action_view.sanitized_allowed_protocols = 'ssh', 'feed'
# end
#
def sanitized_allowed_protocols=(attributes)
HTML::WhiteListSanitizer.allowed_protocols.merge(attributes)
end
end
end
end
end