rather than an action name and *args. The *args were not being used in regular
applications outside tests. This causes a backwards compatibility
issue, but reduces array allocations for most users.
Rails 4.x and earlier didn't support `Mime::Type[:FOO]`, so libraries
that support multiple Rails versions would've had to feature-detect
whether to use `Mime::Type[:FOO]` or `Mime::FOO`.
`Mime[:foo]` has been around for ages to look up registered MIME types
by symbol / extension, though, so libraries and plugins can safely
switch to that without breaking backward- or forward-compatibility.
Note: `Mime::ALL` isn't a real MIME type and isn't registered for lookup
by type or extension, so it's not available as `Mime[:all]`. We use it
internally as a wildcard for `respond_to` negotiation. If you use this
internal constant, continue to reference it with `Mime::ALL`.
Ref. efc6dd550ee49e7e443f9d72785caa0f240def53
We are going to deprecate only on Rails 5 to make easier plugin
maintainers support different Rails versions. Right now we are only
discouraging their usage.
This reverts commit 6c5f43bab8206747a8591435b2aa0ff7051ad3de.
Conflicts:
actionpack/CHANGELOG.md
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.
When helper try to require missing file rails will throw exception about
missing helper.
# app/helpers/my_helper.rb
require 'missing'
module MyHelper
end
And when we try do load helper
class ApplicationController
helper :my
end
Rails will throw exception. This is wrong because there is a helper
file.
Missing helper file helpers/my_helper.rb
Now when helper try to require non-existed file rails will throw proper
exception.
No such file to load -- missing
When setting the layout either by referencing a method or supplying a
Proc there is no way to fall back to the default lookup behavior if
desired. This patch allows fallback to the layout lookup behavior when
returning nil from the proc or method.
