Class | ActiveSupport::LogSubscriber |
In: |
lib/active_support/log_subscriber/test_helper.rb
lib/active_support/log_subscriber.rb |
Parent: | Object |
ActiveSupport::LogSubscriber is an object set to consume ActiveSupport::Notifications with solely purpose of logging. The log subscriber dispatches notifications to a regirested object based on its given namespace.
An example would be Active Record log subscriber responsible for logging queries:
module ActiveRecord class LogSubscriber < ActiveSupport::LogSubscriber def sql(event) "#{event.payload[:name]} (#{event.duration}) #{event.payload[:sql]}" end end end
And it‘s finally registed as:
ActiveRecord::LogSubscriber.attach_to :active_record
Since we need to know all instance methods before attaching the log subscriber, the line above should be called after your ActiveRecord::LogSubscriber definition.
After configured, whenever a "sql.active_record" notification is published, it will properly dispatch the event (ActiveSupport::Notifications::Event) to the sql method.
Log subscriber also has some helpers to deal with logging and automatically flushes all logs when the request finishes (via action_dispatch.callback notification) in a Rails environment.
CLEAR | = | "\e[0m" | Embed in a String to clear all previous ANSI sequences. | |
BOLD | = | "\e[1m" | ||
BLACK | = | "\e[30m" | Colors | |
RED | = | "\e[31m" | ||
GREEN | = | "\e[32m" | ||
YELLOW | = | "\e[33m" | ||
BLUE | = | "\e[34m" | ||
MAGENTA | = | "\e[35m" | ||
CYAN | = | "\e[36m" | ||
WHITE | = | "\e[37m" |
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.