cache

the page is cached .

Hence,  after first request, the same URL's response is deliver from cache, rails is no involved 

3 caches:

page caching,  action caching  & fragment caching

page caching:

ex:

caches_page  :test

action caching:

execute filter before return cached pages

ex:

before_filter  :test_filter

caches_action  :test2

turn on caching( in environment.rb) :

ActionController::Base.perform_caching = true

removing cache:

expire_page

ex:

expire_page  :action=>test

expire_action:

ex:

expire_action :action=>test2

sweeper:

observe the model. When the model is changed, the sweeper expire the cached pages that 

depend on the model

ex:

in app/models

class  TestSweeper <>

         observe  Car

         def  after_create(car)

                   expire_car_page

         end

end

in app/controllers

class Test <>

    cache_sweeper  :test_sweeper

end

the location to store cached pages:

ex:

http://localhost:3000/content/show/1  is stored in app/public/content/show/1.html