Activate caching for the state state. If version_proc is omitted, the view will be cached forever. Otherwise you may either directly pass a Proc or provide a Symbol, which is treated as an instance method of the cell. This method is called every time the state is rendered, and is expected to return a Hash containing the cache key ingredients.

Example:

  class CachingCell < Cell::Base
    cache :versioned_cached_state, Proc.new{ {:version => 0} }

would result in the complete cache key

  cells/CachingCell/versioned_cached_state/version=0

If you provide a symbol, you can access the cell instance directly in the versioning method:

  class CachingCell < Cell::Base
    cache :cached_state, :my_cache_version

    def my_cache_version
      { :user     => current_user.id,
        :item_id  => params[:item] }
      }
    end

results in a very specific cache key, for customized caching:

  cells/CachingCell/cached_state/user=18/item_id=1

[Source]

    # File lib/cell/caching.rb, line 60
60:     def cache(state, version_proc = Proc.new{Hash.new})
61:       #return unless ActionController::Base.cache_configured?
62:       version_procs[state] = version_proc
63:     end