diff options
-rw-r--r-- | actionpack/lib/action_view/renderer/streaming_template_renderer.rb | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/actionpack/lib/action_view/renderer/streaming_template_renderer.rb b/actionpack/lib/action_view/renderer/streaming_template_renderer.rb index 5ef6191d79..acc84a50e7 100644 --- a/actionpack/lib/action_view/renderer/streaming_template_renderer.rb +++ b/actionpack/lib/action_view/renderer/streaming_template_renderer.rb @@ -1,6 +1,53 @@ require 'fiber' module ActionView + # Consider the following layout: + # + # <%= yield :header %> + # 2 + # <%= yield %> + # 5 + # <%= yield :footer %> + # + # And template: + # + # <%= provide :header, "1" %> + # 3 + # 4 + # <%= provide :footer, "6" %> + # + # It will stream: + # + # "1\n", "2\n", "3\n4\n", "5\n", "6\n" + # + # Notice that once you <%= yield %>, it will render the whole template + # before streaming again. In the future, we can also support streaming + # from the template and not only the layout. + # + # Also, notice we use +provide+ instead of +content_for+, as +provide+ + # gives the control back to the layout as soon as it is called. + # With +content_for+, it would render all the template to find all + # +content_for+ calls. For instance, consider this layout: + # + # <%= yield :header %> + # + # With this template: + # + # <%= content_for :header, "1" %> + # <%= provide :header, "2" %> + # <%= provide :header, "3" %> + # + # It will return "12\n" because +content_for+ continues rendering the + # template but it is returns back to the layout as soon as it sees the + # first +provide+. + # + # == TODO + # + # * Add streaming support in the controllers with no-cache settings + # * What should happen when an error happens? + # * Support streaming from child templates, partials and so on. + # * Support on sprockets async JS load? + # class StreamingTemplateRenderer < TemplateRenderer #:nodoc: # A valid Rack::Body (i.e. it responds to each). # It is initialized with a block that, when called, starts |