rails--rails/actionpack/lib/action_controller/metal/etag_with_template_digest.rb

58 lines
1.9 KiB
Ruby

# frozen_string_literal: true
module ActionController
# When our views change, they should bubble up into HTTP cache freshness
# and bust browser caches. So the template digest for the current action
# is automatically included in the ETag.
#
# Enabled by default for apps that use Action View. Disable by setting
#
# config.action_controller.etag_with_template_digest = false
#
# Override the template to digest by passing +:template+ to +fresh_when+
# and +stale?+ calls. For example:
#
# # We're going to render widgets/show, not posts/show
# fresh_when @post, template: 'widgets/show'
#
# # We're not going to render a template, so omit it from the ETag.
# fresh_when @post, template: false
#
module EtagWithTemplateDigest
extend ActiveSupport::Concern
include ActionController::ConditionalGet
included do
class_attribute :etag_with_template_digest, default: true
ActiveSupport.on_load :action_view, yield: true do
etag do |options|
determine_template_etag(options) if etag_with_template_digest
end
end
end
private
def determine_template_etag(options)
if template = pick_template_for_etag(options)
lookup_and_digest_template(template)
end
end
# Pick the template digest to include in the ETag. If the +:template+ option
# is present, use the named template. If +:template+ is +nil+ or absent, use
# the default controller/action template. If +:template+ is false, omit the
# template digest from the ETag.
def pick_template_for_etag(options)
unless options[:template] == false
options[:template] || "#{controller_path}/#{action_name}"
end
end
def lookup_and_digest_template(template)
ActionView::Digestor.digest name: template, format: nil, finder: lookup_context
end
end
end