Resetting the template or class cache in Rails 2.2.0


#1

While testing the Rails 2.2.0 release I soon knew I had a problem: I’m
relying on the fact that an ERB template is recompiled if the
modification time of the file has been updated.

I work on a multisite Rails app, which uses ‘request.host’ to do a
Site.find_by_domain and uses a before filter to call
‘prepend_view_path("#{RAILS_ROOT}/themes/#{@site.domain}/templates").
It’s also possible to upload a new theme for a specific site via an
admin backend.
It’s comparable to Shopify, but instead of using Liquid it relies on
Rails’ templating mechanism.

The line of code that made this work is located here:
http://github.com/rails/rails/tree/v2.1.2/actionpack/lib/action_view/template_handlers/compilable.rb#L70,
but in rails-2.2.0 thing have been rewritten and the check is
unfortunately gone:
http://github.com/rails/rails/tree/v2.2.0/actionpack/lib/action_view/renderable.rb#L90.

Currently this means that I need to run this app in production with
‘config.cache_classes = false’ in order to upgrade to Rails 2.2.0,
which reloads all application code on every requests. That’s going to
be slow. Another solution is restarting the whole app after changing
the theme for a single site.

Is there a way for me to reset the template cache manually after a
theme has been updated?


#2

On 31 Oct 2008, at 12:36, Matthijs L. wrote:

It’s comparable to Shopify, but instead of using Liquid it relies on
‘config.cache_classes = false’ in order to upgrade to Rails 2.2.0,
which reloads all application code on every requests. That’s going to
be slow. Another solution is restarting the whole app after changing
the theme for a single site.

Is there a way for me to reset the template cache manually after a
theme has been updated?
You could just override that recompile? method

Fred


#3

Fred,

I think I could write a patch that will take the file modification
date into consideration, but I’m also eager to know, why the check has
actually been removed.

  • Matthijs

On Oct 31, 2:01 pm, Frederick C. removed_email_address@domain.invalid


#4

I don’t understand. If checking if a template has already been
compiled is thread-safe, checking the modification date should also be
thread-safe.

If thread safety is the issue here, would there be an option for me to
reset all compiled templates at once?

On Oct 31, 2:08 pm, “Maurício Linhares” removed_email_address@domain.invalid


#5

Maybe you could remove the whole compliled templates folder.

Maurício Linhares
http://alinhavado.wordpress.com/ (pt-br) | http://blog.codevader.com/
(en)
João Pessoa, PB, +55 83 8867-7208

On Fri, Oct 31, 2008 at 1:35 PM, Matthijs L.


#6

My bet is that it isn’t thread-safe. Two actions may check at the same
time, both will get a “true” and both will try to update the cache.

Maurício Linhares
http://alinhavado.wordpress.com/ (pt-br) | http://blog.codevader.com/
(en)
João Pessoa, PB, +55 83 8867-7208

On Fri, Oct 31, 2008 at 10:06 AM, Matthijs L.


#7

Hi guys,

I’m trying to get themes working in my app. I’m using the
prepend_view_path in a before filter. Everything seems to work great…
however, it won’t render layouts from the theme location… it only
renders the rest of the view files from the theme location and the
layouts are from the default /app/views location…

Any ideas on how to solve this?

I’m using the Rails 2.3RC1…


#8

After doing some git-bisect magic it seems I’m in some real trouble.
Josh P. intentionally disabled[1] the file modification time check.

@Mauricio, are you sure compiled templates are stored on disk?

[1]
http://github.com/rails/rails/commit/ce5d958f8fe878465c0d2142991a2945ca8d3cd1

On Oct 31, 5:39 pm, “Maurício Linhares” removed_email_address@domain.invalid