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author | Mikel Lindsaar <raasdnil@gmail.com> | 2010-01-17 12:46:51 +1100 |
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committer | Mikel Lindsaar <raasdnil@gmail.com> | 2010-01-17 12:46:51 +1100 |
commit | 6f663addaa7ed40f1133687d7a2be0958bf0c059 (patch) | |
tree | 7beb7f092c1979d1fd5ea6e7aaaf4f59c2f4abf4 /railties/lib/rails/subscriber.rb | |
parent | 8834b2612b7ddda70ee6a685eb0063d3daa8e63d (diff) | |
parent | 3e94032227d450d479f511070c51f37f53d0ecc4 (diff) | |
download | rails-6f663addaa7ed40f1133687d7a2be0958bf0c059.tar.gz rails-6f663addaa7ed40f1133687d7a2be0958bf0c059.tar.bz2 rails-6f663addaa7ed40f1133687d7a2be0958bf0c059.zip |
Merge branch 'master' of github.com:lifo/docrails
Diffstat (limited to 'railties/lib/rails/subscriber.rb')
-rw-r--r-- | railties/lib/rails/subscriber.rb | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/railties/lib/rails/subscriber.rb b/railties/lib/rails/subscriber.rb new file mode 100644 index 0000000000..e8d13babf0 --- /dev/null +++ b/railties/lib/rails/subscriber.rb @@ -0,0 +1,109 @@ +require 'active_support/core_ext/class/inheritable_attributes' +require 'active_support/notifications' + +module Rails + # Rails::Subscriber is an object set to consume ActiveSupport::Notifications + # on initialization with solely purpose of logging. The subscriber dispatches + # notifications to a regirested object based on its given namespace. + # + # An example would be ActiveRecord subscriber responsible for logging queries: + # + # module ActiveRecord + # class Railtie + # class Subscriber < Rails::Subscriber + # def sql(event) + # "#{event.payload[:name]} (#{event.duration}) #{event.payload[:sql]}" + # end + # end + # end + # end + # + # It's finally registed as: + # + # Rails::Subscriber.add :active_record, ActiveRecord::Railtie::Subscriber.new + # + # So whenever a "active_record.sql" notification arrive to Rails::Subscriber, + # it will properly dispatch the event (ActiveSupport::Notifications::Event) to + # the sql method. + # + # This is useful because it avoids spanning several subscribers just for logging + # purposes(which slows down the main thread). Besides of providing a centralized + # facility on top of Rails.logger. + # + # Subscriber also has some helpers to deal with logging and automatically flushes + # all logs when the request finishes (via action_dispatch.callback notification). + class Subscriber + mattr_accessor :colorize_logging, :log_tailer + self.colorize_logging = true + + # Embed in a String to clear all previous ANSI sequences. + CLEAR = "\e[0m" + BOLD = "\e[1m" + + # Colors + BLACK = "\e[30m" + RED = "\e[31m" + GREEN = "\e[32m" + YELLOW = "\e[33m" + BLUE = "\e[34m" + MAGENTA = "\e[35m" + CYAN = "\e[36m" + WHITE = "\e[37m" + + def self.add(namespace, subscriber) + subscribers[namespace.to_sym] = subscriber + end + + def self.subscribers + @subscribers ||= {} + end + + def self.dispatch(args) + namespace, name = args[0].split(".") + subscriber = subscribers[namespace.to_sym] + + if subscriber.respond_to?(name) && subscriber.logger + subscriber.send(name, ActiveSupport::Notifications::Event.new(*args)) + end + + if args[0] == "action_dispatch.callback" && !subscribers.empty? + flush_all! + log_tailer.tail! if log_tailer + end + end + + # Flush all subscribers' logger. + def self.flush_all! + loggers = subscribers.values.map(&:logger) + loggers.uniq! + loggers.each { |l| l.flush if l.respond_to?(:flush) } + end + + # By default, we use the Rails.logger for logging. + def logger + Rails.logger + end + + protected + + %w(info debug warn error fatal unknown).each do |level| + class_eval <<-METHOD, __FILE__, __LINE__ + 1 + def #{level}(*args, &block) + logger.#{level}(*args, &block) + end + METHOD + end + + # Set color by using a string or one of the defined constants. If a third + # option is set to true, it also adds bold to the string. This is based + # on Highline implementation and it automatically appends CLEAR to the end + # of the returned String. + # + def color(text, color, bold=false) + return text unless colorize_logging + color = self.class.const_get(color.to_s.upcase) if color.is_a?(Symbol) + bold = bold ? BOLD : "" + "#{bold}#{color}#{text}#{CLEAR}" + end + end +end
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