diff options
Diffstat (limited to 'actionview/lib/action_view/helpers/cache_helper.rb')
| -rw-r--r-- | actionview/lib/action_view/helpers/cache_helper.rb | 73 |
1 files changed, 37 insertions, 36 deletions
diff --git a/actionview/lib/action_view/helpers/cache_helper.rb b/actionview/lib/action_view/helpers/cache_helper.rb index 401f398721..5258a01144 100644 --- a/actionview/lib/action_view/helpers/cache_helper.rb +++ b/actionview/lib/action_view/helpers/cache_helper.rb @@ -41,11 +41,11 @@ module ActionView # # ==== \Template digest # - # The template digest that's added to the cache key is computed by taking an md5 of the + # The template digest that's added to the cache key is computed by taking an MD5 of the # contents of the entire template file. This ensures that your caches will automatically # expire when you change the template file. # - # Note that the md5 is taken of the entire template file, not just what's within the + # Note that the MD5 is taken of the entire template file, not just what's within the # cache do/end call. So it's possible that changing something outside of that call will # still expire the cache. # @@ -69,11 +69,11 @@ module ActionView # render 'comments/comments' # render('comments/comments') # - # render "header" => render("comments/header") + # render "header" translates to render("comments/header") # - # render(@topic) => render("topics/topic") - # render(topics) => render("topics/topic") - # render(message.topics) => render("topics/topic") + # render(@topic) translates to render("topics/topic") + # render(topics) translates to render("topics/topic") + # render(message.topics) translates to render("topics/topic") # # It's not possible to derive all render calls like that, though. # Here are a few examples of things that can't be derived: @@ -118,7 +118,7 @@ module ActionView # # If you use a helper method, for example, inside a cached block and # you then update that helper, you'll have to bump the cache as well. - # It doesn't really matter how you do it, but the md5 of the template file + # It doesn't really matter how you do it, but the MD5 of the template file # must change. One recommendation is to simply be explicit in a comment, like: # # <%# Helper Dependency Updated: May 6, 2012 at 6pm %> @@ -126,44 +126,38 @@ module ActionView # # Now all you have to do is change that timestamp when the helper method changes. # - # === Automatic Collection Caching + # === Collection Caching # - # When rendering collections such as: + # When rendering a collection of objects that each use the same partial, a `cached` + # option can be passed. # - # <%= render @notifications %> - # <%= render partial: 'notifications/notification', collection: @notifications %> + # For collections rendered such: # - # If the notifications/_notification partial starts with a cache call as: + # <%= render partial: 'projects/project', collection: @projects, cached: true %> # - # <% cache notification do %> - # <%= notification.name %> - # <% end %> - # - # The collection can then automatically use any cached renders for that - # template by reading them at once instead of one by one. + # The `cached: true` will make Action View's rendering read several templates + # from cache at once instead of one call per template. # - # See ActionView::Template::Handlers::ERB.resource_cache_call_pattern for - # more information on what cache calls make a template eligible for this - # collection caching. + # Templates in the collection not already cached are written to cache. # - # The automatic cache multi read can be turned off like so: + # Works great alongside individual template fragment caching. + # For instance if the template the collection renders is cached like: # - # <%= render @notifications, cache: false %> + # # projects/_project.html.erb + # <% cache project do %> + # <%# ... %> + # <% end %> # - # === Explicit Collection Caching + # Any collection renders will find those cached templates when attempting + # to read multiple templates at once. # - # If the partial template doesn't start with a clean cache call as - # mentioned above, you can still benefit from collection caching by - # adding a special comment format anywhere in the template, like: + # If your collection cache depends on multiple sources (try to avoid this to keep things simple), + # you can name all these dependencies as part of a block that returns an array: # - # <%# Template Collection: notification %> - # <% my_helper_that_calls_cache(some_arg, notification) do %> - # <%= notification.name %> - # <% end %> + # <%= render partial: 'projects/project', collection: @projects, cached: -> project { [ project, current_user ] } %> # - # The pattern used to match these is <tt>/# Template Collection: (\S+)/</tt>, - # so it's important that you type it out just so. - # You can only declare one collection in a partial template file. + # This will include both records as part of the cache key and updating either of them will + # expire the cache. def cache(name = {}, options = {}, &block) if controller.respond_to?(:perform_caching) && controller.perform_caching name_options = options.slice(:skip_digest, :virtual_path) @@ -217,6 +211,8 @@ module ActionView end end + attr_reader :cache_hit # :nodoc: + private def fragment_name_with_digest(name, virtual_path) #:nodoc: @@ -230,9 +226,14 @@ module ActionView end end - # TODO: Create an object that has caching read/write on it def fragment_for(name = {}, options = nil, &block) #:nodoc: - read_fragment_for(name, options) || write_fragment_for(name, options, &block) + if content = read_fragment_for(name, options) + @cache_hit = true + content + else + @cache_hit = false + write_fragment_for(name, options, &block) + end end def read_fragment_for(name, options) #:nodoc: |