WIP: Image gallery support

3 files changed, 121 insertions, 7 deletions

diff --git a/lib/action_text.rb b/lib/action_text.rb
index 0559dce2ba..4182cacb8a 100644
--- a/lib/action_text.rb
+++ b/lib/action_text.rb
@@ -8,6 +8,7 @@ module ActionText
   mattr_accessor(:renderer)
 
   autoload :Attachable
+  autoload :AttachmentGallery
   autoload :Attachment
   autoload :Attribute
   autoload :Content
diff --git a/lib/action_text/attachment_gallery.rb b/lib/action_text/attachment_gallery.rb
new file mode 100644
index 0000000000..6f690551e6
--- /dev/null
+++ b/lib/action_text/attachment_gallery.rb
@@ -0,0 +1,62 @@
+module ActionText
+  class AttachmentGallery
+    include ActiveModel::Model
+
+    class << self
+      def fragment_by_canonicalizing_attachment_galleries(content)
+        fragment_by_replacing_attachment_gallery_nodes(content) do |node|
+          "<#{TAG_NAME}>#{node.inner_html}</#{TAG_NAME}>"
+        end
+      end
+
+      def fragment_by_replacing_attachment_gallery_nodes(content)
+        Fragment.wrap(content).update do |source|
+          find_attachment_gallery_nodes(source).each do |node|
+            node.replace(yield(node).to_s)
+          end
+        end
+      end
+
+      def find_attachment_gallery_nodes(content)
+        Fragment.wrap(content).find_all(SELECTOR).select do |node|
+          node.children.all? do |child|
+            if child.text?
+              child.text =~ /\A(\n|\ )*\z/
+            else
+              child.matches? ATTACHMENT_SELECTOR
+            end
+          end
+        end
+      end
+
+      def from_node(node)
+        new(node)
+      end
+    end
+
+    attr_reader :node
+
+    def initialize(node)
+      @node = node
+    end
+
+    def attachments
+      @attachments ||= node.css(ATTACHMENT_SELECTOR).map do |node|
+        ActionText::Attachment.from_node(node).with_full_attributes
+      end
+    end
+
+    def size
+      attachments.size
+    end
+
+    def inspect
+      "#<#{self.class.name} size=#{size.inspect}>"
+    end
+
+    private
+      TAG_NAME = "div"
+      ATTACHMENT_SELECTOR = "#{ActionText::Attachment::SELECTOR}[presentation=gallery]"
+      SELECTOR = "#{TAG_NAME}:has(#{ATTACHMENT_SELECTOR} + #{ATTACHMENT_SELECTOR})"
+  end
+end
diff --git a/lib/action_text/content.rb b/lib/action_text/content.rb
index 22b52cff1c..71d9e98657 100644
--- a/lib/action_text/content.rb
+++ b/lib/action_text/content.rb
@@ -6,8 +6,22 @@ module ActionText
 
     delegate :blank?, :empty?, :html_safe, :present?, to: :to_html # Delegating to to_html to avoid including the layout
 
-    def initialize(content = nil)
-      @fragment = ActionText::Attachment.fragment_by_canonicalizing_attachments(content)
+    class << self
+      def fragment_by_canonicalizing_content(content)
+        fragment = ActionText::Attachment.fragment_by_canonicalizing_attachments(content)
+        fragment = ActionText::AttachmentGallery.fragment_by_canonicalizing_attachment_galleries(fragment)
+        fragment
+      end
+    end
+
+    def initialize(content = nil, options = {})
+      options.with_defaults! canonicalize: true
+
+      if options[:canonicalize]
+        @fragment = self.class.fragment_by_canonicalizing_content(content)
+      else
+        @fragment = ActionText::Fragment.wrap(content)
+      end
     end
 
     def links
@@ -20,6 +34,16 @@ module ActionText
       end
     end
 
+    def attachment_galleries
+      @attachment_galleries ||= attachment_gallery_nodes.map do |node|
+        attachment_gallery_for_node(node)
+      end
+    end
+
+    def gallery_attachments
+      @gallery_attachments ||= attachment_galleries.flat_map(&:attachments)
+    end
+
     def attachables
       @attachables ||= attachment_nodes.map do |node|
         ActionText::Attachable.from_node(node)
@@ -32,13 +56,21 @@ module ActionText
     end
 
     def render_attachments(**options, &block)
-      fragment.replace(ActionText::Attachment::SELECTOR) do |node|
+      content = fragment.replace(ActionText::Attachment::SELECTOR) do |node|
         block.call(attachment_for_node(node, **options))
       end
+      self.class.new(content, canonicalize: false)
+    end
+
+    def render_attachment_galleries(**options, &block)
+      content = ActionText::AttachmentGallery.fragment_by_replacing_attachment_gallery_nodes(fragment) do |node|
+        block.call(attachment_gallery_for_node(node, **options))
+      end
+      self.class.new(content, canonicalize: false)
     end
 
     def to_plain_text
-      render_attachments(with_full_attributes: false, &:to_plain_text).to_plain_text
+      render_attachments(with_full_attributes: false, &:to_plain_text).fragment.to_plain_text
     end
 
     def to_trix_html
@@ -46,19 +78,30 @@ module ActionText
     end
 
     def to_html
+      fragment.to_html
+    end
+
+    def to_rendered_html
       render_attachments do |attachment|
         attachment.node.tap do |node|
           node.inner_html = ActionText.renderer.render(attachment)
         end
+      end.render_attachment_galleries do |attachment_gallery|
+        ActionText.renderer.render(layout: attachment_gallery, object: attachment_gallery, formats: "html") do
+          attachment_gallery.attachments.map do |attachment|
+            attachment.node.inner_html = ActionText.renderer.render(attachment)
+            attachment.to_html
+          end.join("").html_safe
+        end
       end.to_html
     end
 
-    def to_html_with_layout
-      ActionText.renderer.render(partial: "action_text/content/layout", locals: { document: to_html })
+    def to_rendered_html_with_layout
+      ActionText.renderer.render(partial: "action_text/content/layout", locals: { document: to_rendered_html })
     end
 
     def to_s
-      to_html_with_layout
+      to_rendered_html_with_layout
     end
 
     def as_json(*)
@@ -80,9 +123,17 @@ module ActionText
         @attachment_nodes ||= fragment.find_all(ActionText::Attachment::SELECTOR)
       end
 
+      def attachment_gallery_nodes
+        @attachment_gallery_nodes ||= ActionText::AttachmentGallery.find_attachment_gallery_nodes(fragment)
+      end
+
       def attachment_for_node(node, with_full_attributes: true)
         attachment = ActionText::Attachment.from_node(node)
         with_full_attributes ? attachment.with_full_attributes : attachment
       end
+
+      def attachment_gallery_for_node(node, **options)
+        ActionText::AttachmentGallery.from_node(node)
+      end
   end
 end