Rails%203%20In%20Action

Page and action caching
However, when you click the Ticketee Beta link to go to your first project, the page
will change to saying that you’re signed in as the admin@ticketee.com user again, as
shown in figure 16.8.
You know better; you’re actually signed in as the user! This is happening because
Rails has cached the entire page, rather than just the tickets list. This page also
ignores any kind of authorization you’ve set up in your controllers, making it available
for every single person who wishes to access it, which is just a Very Bad Thing.
So it looks like caches_page isn’t going to work in this situation. This method is
better for pages that don’t have dynamic elements on them, such as the place at the
top that displays the currently logged-in user or the list of tickets.
This method has a brother called caches_action that will help you fix both the
issue of the currently logged-in user display message, as well as the issue of it only
showing the first page of pagination.
16.3.2 Caching an action
Caching an entire page is helpful when you don’t have authentication, but if you have
authentication then it’s better to cache the response of the action on a per-user basis.
Caching an action involves caching the response for a particular session, so that when
that user requests it again they’ll be shown it again.
Caching a page is great for a page that’s accessible by anybody, as the body would
be served as a static file from the public folder by the web server. Caching an action is
best used for actions that take a long time to process (you don’t have any at the
moment) and that require some interaction with the Rails stack, such as a
before_filter that authenticates your user.
There’s a third way of caching, and that’s fragment caching, where you’d cache just a
bit of a page at a time, rather than the entire result. Before you get on to using that,
let’s see what caches_action provides you.
NOTE Before you do anything, you’ll want to remove the old file that has
been cached. To do this, delete the public/projects directory. Next time
this page is requested, the cache will be re-created.
Let’s replace this line in your ProjectsController
caches_page :show
Figure 16.8 Still signed in
as admin@ticketee.com?
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