actionview/lib/action_view/log_subscriber.rb
# frozen_string_literal: true
require "active_support/log_subscriber"
module ActionView
# = Action View Log Subscriber
#
# Provides functionality so that \Rails can output logs from Action View.
class LogSubscriber < ActiveSupport::LogSubscriber
VIEWS_PATTERN = /^app\/views\//
def initialize
@root = nil
super
end
def render_template(event)
info do
message = +" Rendered #{from_rails_root(event.payload[:identifier])}"
message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
message << " (Duration: #{event.duration.round(1)}ms | GC: #{event.gc_time.round(1)}ms)"
end
end
subscribe_log_level :render_template, :debug
def render_partial(event)
debug do
message = +" Rendered #{from_rails_root(event.payload[:identifier])}"
message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
message << " (Duration: #{event.duration.round(1)}ms | GC: #{event.gc_time.round(1)}ms)"
message << " #{cache_message(event.payload)}" unless event.payload[:cache_hit].nil?
message
end
end
subscribe_log_level :render_partial, :debug
def render_layout(event)
info do
message = +" Rendered layout #{from_rails_root(event.payload[:identifier])}"
message << " (Duration: #{event.duration.round(1)}ms | GC: #{event.gc_time.round(1)}ms)"
end
end
subscribe_log_level :render_layout, :info
def render_collection(event)
identifier = event.payload[:identifier] || "templates"
debug do
message = +" Rendered collection of #{from_rails_root(identifier)}"
message << " within #{from_rails_root(event.payload[:layout])}" if event.payload[:layout]
message << " #{render_count(event.payload)} (Duration: #{event.duration.round(1)}ms | GC: #{event.gc_time.round(1)}ms)"
message
end
end
subscribe_log_level :render_collection, :debug
module Utils # :nodoc:
def logger
ActionView::Base.logger
end
private
def from_rails_root(string)
string = string.sub(rails_root, "")
string.sub!(VIEWS_PATTERN, "")
string
end
def rails_root # :doc:
@root ||= "#{Rails.root}/"
end
end
include Utils
class Start # :nodoc:
include Utils
def start(name, id, payload)
return unless logger
logger.debug do
qualifier =
if name == "render_template.action_view"
""
elsif name == "render_layout.action_view"
"layout "
end
return unless qualifier
message = +" Rendering #{qualifier}#{from_rails_root(payload[:identifier])}"
message << " within #{from_rails_root(payload[:layout])}" if payload[:layout]
message
end
end
def finish(name, id, payload)
end
def silenced?(_)
logger.nil? || !logger.debug?
end
end
def self.attach_to(*)
ActiveSupport::Notifications.subscribe("render_template.action_view", ActionView::LogSubscriber::Start.new)
ActiveSupport::Notifications.subscribe("render_layout.action_view", ActionView::LogSubscriber::Start.new)
super
end
private
def render_count(payload) # :doc:
if payload[:cache_hits]
"[#{payload[:cache_hits]} / #{payload[:count]} cache hits]"
else
"[#{payload[:count]} times]"
end
end
def cache_message(payload) # :doc:
case payload[:cache_hit]
when :hit
"[cache hit]"
when :miss
"[cache miss]"
end
end
end
end
ActionView::LogSubscriber.attach_to :action_view