1 files changed, 91 insertions, 0 deletions
diff --git a/actionview/lib/action_view/helpers/sanitize_helper/scrubbers.rb b/actionview/lib/action_view/helpers/sanitize_helper/scrubbers.rb
new file mode 100644
index 0000000000..2dfe82efab
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+++ b/actionview/lib/action_view/helpers/sanitize_helper/scrubbers.rb
@@ -0,0 +1,91 @@
+# === PermitScrubber
+#
+# PermitScrubber allows you to permit only your own tags and/or attributes.
+#
+# Supplied tags and attributes should be Enumerables
+#
+# +tags=+
+# If this value is set all other elements will be stripped (their inner elements will be kept).
+# If not set elements for which HTML5::Scrub.allowed_element? is false will be stripped.
+#
+# +attributes=+
+# Contain an elements allowed attributes.
+# If none is set HTML5::Scrub.scrub_attributes implementation will be used.
+#
+# Subclass PermitScrubber to provide your own definition of
+# when a node is allowed and how attributes should be scrubbed.
+class PermitScrubber < Loofah::Scrubber
+  # :nodoc:
+  attr_reader :tags, :attributes
+
+  def tags=(tags)
+    @tags = validate!(tags, :tags)
+  end
+
+  def attributes=(attributes)
+    @attributes = validate!(attributes, :attributes)
+  end
+
+  def scrub(node)
+    return CONTINUE if should_skip_node?(node)
+
+    unless allowed_node?(node)
+      node.before node.children # strip
+      node.remove
+      return STOP
+    end
+
+    scrub_attributes(node)
+  end
+
+  protected
+
+  def allowed_node?(node)
+    if @tags
+      @tags.include?(node.name)
+    else
+      Loofah::HTML5::Scrub.allowed_element?(node.name)
+    end
+  end
+
+  def scrub_attributes(node)
+    if @attributes
+      node.attributes.each do |name, _|
+        node.remove_attribute(name) unless @attributes.include?(name)
+      end
+    else
+      Loofah::HTML5::Scrub.scrub_attributes(node)
+    end
+  end
+
+  def should_skip_node?(node)
+    text_or_cdata_node?(node)
+  end
+
+  def text_or_cdata_node?(node)
+    case node.type
+    when Nokogiri::XML::Node::TEXT_NODE, Nokogiri::XML::Node::CDATA_SECTION_NODE
+      return true
+    end
+    false
+  end
+
+  def validate!(var, name)
+    if var && !var.is_a?(Enumerable)
+      raise ArgumentError, "You should pass :#{name} as an Enumerable"
+    end
+    var
+  end
+end
+
+# LinkScrubber overrides PermitScrubbers +allowed_node?+ to any nodes
+# which names aren't a or href
+class LinkScrubber < PermitScrubber
+  def initialize
+    @strip_tags = %w(a href)
+  end
+
+  def allowed_node?(node)
+    !@strip_tags.include?(node.name)
+  end
+end