Fragment caching

I would like to fragment cache part of a page.

On the view I have

<% cache("saved_area") do %>
.
 <% end -%>

In the controller:

  def index 

   read_fragmen开发者_JAVA技巧t("saved_area")

   end

In config/production:

   config.cache_store = :file_store, File.join(RAILS_ROOT, 'tmp', 'cache') 

The file was created in the tmp/cache directory. But I am not sure if the cache is being used in the request, since I presume there should be a line in the log stating that the cache is being used (and there is not).

Rails sets the log level in production mode to :info, hence it does not log cache hits and misses. If you set

config.log_level = :debug 

in your config/enviroments/production.rb, then you see messages like:

Cached fragment hit: views/test (0.2ms)
Cached fragment miss: views/test (1.8ms)

in your log. The second solution is to configure your development environment to perform caching, since :debug is the default log level in this environment. This can be done by setting:

config.action_controller.perform_caching = true
config.cache_store = :file_store, File.join(RAILS_ROOT, 'tmp', 'cache') 

This is the best way to do this, since if your app goes into production, you won't log that much.

BTW: You don't have to call read_fragment in your controller. The cache helper method will do this for you.