Cached pages with updated partials.

Serve completely cached pages, but keep e.g. "Welcome <%= current_user %>" updated.
Does not influence not-cached actions.

Up and running in 23 seconds or money back!

Rails 2 Version

gem install easy_esi

class UsersController < ApplicationController
  caches_action :show
  enable_esi
end

Has no effect for non-esi controllers! <%= render 'profile' %> IS NOW <%= esi_render 'profile' %>

<%= render 'profile', :local_variable => :foo %>
IS NOW
<%= esi_render :partial => 'profile', :locals => {:local_variable => :foo} %>

esi_render inserts an esi-include (<esi:include .... />).
an after_filter or easy-esi-rails-cache-hack replaces these by rendering the partial.
==> if you want to share view caches between controllers, call enable_esi in all of them (or in ApplicationController).

Normally ESI means having an extra server that parses <esi> tags and then calls your app to render these partials. Which adds a whole lot of new problems(passing arguments, login, expiration, security...). On top of that it will slow down your application unless you do everything so perfect that it gets faster then a action-cached request (which is really hard...).

With 'hard' Esi, each <esi> tag causes a new, (yet small) request which needs to load all data (instance-variables) anew.
With easy-esi, each <esi> tag causes a partial to be rendered, inside the current context, re-using instance-variables.

Compared to normal ESI this means:

• Testable caching
• Enabled per-controller
• No global changes
• Deactivatable at any moment
• before-filters still work
• No extra server
• No new actions
• No duplicate server requests
• No new configuration language
• No purge requests
• No external dependencies
• ...

• Nils Landt

Michael Grosser
michael@grosser.it
License: MIT