A few have been left for aesthetic reasons, but have made a pass
and removed most of them.
Note that if the method `foo` returns an array, `foo << 1`
is a regular push, nothing to do with assignments, so
no self required.
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
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.
Assuming the type ":touch", Collector.new was calling
send(:touch), which instead of triggering method_missing
and generating a new collector method, actually
invoked the private method `touch` inherited from
Object.
By generating the method for each mime type as it
is registered, the private methods on Object can
never be reached by `send`, because the `Collector`
will have them before `send` is called on it.
To do this, a callback mechanism was added to Mime::Type
This allows someone to add a callback for whenever
a new mime type is registered. The callback then
gets called with the new mime as a parameter.
This is then used in AbstractController::Collector
to generate new collector methods after each mime
is registered.
