Given the following templates:
mailer/demo.html.erb
mailer/demo.en.html.erb
mailer/demo.pt.html.erb
Before this change for a locale that doesn't have its related file
the `mailer/demo.html.erb` will
be rendered even if `en` is the default locale.
Now `mailer/demo.en.html.erb` has precedence over the file without
locale.
Also, it is possible to give a fallback.
mailer/demo.pt.html.erb
mailer/demo.pt-BR.html.erb
So if the locale is `pt-PT`, `mailer/demo.pt.html.erb` will be
rendered given the right I18n fallback configuration.
Fixes#11884.
The performance is almost the same with both implementations but this is
clear.
Before this patch:
Calculating -------------------------------------
small erb template 1452 i/100ms
-------------------------------------------------
small erb template 17462.1 (±13.3%) i/s - 85668 in 5.031395s
.Calculating -------------------------------------
small erb template with 1 partial
887 i/100ms
-------------------------------------------------
small erb template with 1 partial
8899.6 (±18.8%) i/s - 42576 in 5.009453s
.Calculating -------------------------------------
small erb template with 2 partials
666 i/100ms
-------------------------------------------------
small erb template with 2 partials
6821.5 (±8.8%) i/s - 33966 in 5.020791s
After the patch:
Calculating -------------------------------------
small erb template 1479 i/100ms
-------------------------------------------------
small erb template 15956.6 (±7.6%) i/s - 79866 in 5.036001s
.Calculating -------------------------------------
small erb template with 1 partial
841 i/100ms
-------------------------------------------------
small erb template with 1 partial
9242.2 (±6.9%) i/s - 46255 in 5.029497s
.Calculating -------------------------------------
small erb template with 2 partials
615 i/100ms
-------------------------------------------------
small erb template with 2 partials
6524.7 (±6.8%) i/s - 32595 in 5.020456s
You can find the benchmark code at
https://gist.github.com/rafaelfranca/dee31120cfdb1ddc3b56
Using ruby-prof, I noticed that Set#add had the largest 'self time'
percentage (5% of the overall time spent rendering) when
benchmarking the rendering of a small cached ERB template that was 3
lines long. It turns out it was from this line. I don't believe the
Set is necessary, either. Removing this line increases the rendering
ips using Benchmark::ips accordingly.
LookupContext is eagerly loaded, and FallbackFileSystemResolver is
referenced at the class level. Just require the resolver from the
eagerly loaded class rather than jumping through autoload hoops
By default, variants in the templates will be picked up if a variant is set
and there's a match. The format will be:
app/views/projects/show.html.erb
app/views/projects/show.html+tablet.erb
app/views/projects/show.html+phone.erb
If request.variant = :tablet is set, we'll automatically be rendering the
html+tablet template.
In the controller, we can also tailer to the variants with this syntax:
class ProjectsController < ActionController::Base
def show
respond_to do |format|
format.html do |html|
@stars = @project.stars
html.tablet { @notifications = @project.notifications }
html.phone { @chat_heads = @project.chat_heads }
end
format.js
format.atom
end
end
end
The variant itself is nil by default, but can be set in before filters, like
so:
class ApplicationController < ActionController::Base
before_action do
if request.user_agent =~ /iPad/
request.variant = :tablet
end
end
end
This is modeled loosely on custom mime types, but it's specifically not
intended to be used together. If you're going to make a custom mime type,
you don't need a variant. Variants are for variations on a single mime
types.
