|||
You probably spend a lot of time in IRB (or the Rails console) but have you taken the time to customize it? Today we’ll take a look at the things I’ve added to mine, and I’ll show you how to hack in a .irbrc_rails that’s only loaded in the Rails console.
# ruby 1.8.7 compatible
require 'rubygems'
require 'irb/completion'
# interactive editor: use vim from within irb
begin
require 'interactive_editor'
rescue LoadError => err
warn "Couldn't load interactive_editor: #{err}"
end
# awesome print
begin
require 'awesome_print'
AwesomePrint.irb!
rescue LoadError => err
warn "Couldn't load awesome_print: #{err}"
end
# configure irb
IRB.conf[:PROMPT_MODE] = :SIMPLE
# irb history
IRB.conf[:EVAL_HISTORY] = 1000
IRB.conf[:SAVE_HISTORY] = 1000
IRB.conf[:HISTORY_FILE] = File::expand_path("~/.irbhistory")
# load .irbrc_rails in rails environments
railsrc_path = File.expand_path('~/.irbrc_rails')
if ( ENV['RAILS_ENV'] || defined? Rails ) && File.exist?( railsrc_path )
begin
load railsrc_path
rescue Exception
warn "Could not load: #{ railsrc_path } because of #{$!.message}"
end
end
class Object
def interesting_methods
case self.class
when Class
self.public_methods.sort - Object.public_methods
when Module
self.public_methods.sort - Module.public_methods
else
self.public_methods.sort - Object.new.public_methods
end
end
endOk! There’s not too much there, but let’s break it down from top to bottom.
# ruby 1.8.7 compatible
require 'rubygems'
require 'irb/completion'
# interactive editor: use vim from within irb
begin
require 'interactive_editor'
rescue LoadError => err
warn "Couldn't load interactive_editor: #{err}"
end
# awesome print
begin
require 'awesome_print'
AwesomePrint.irb!
rescue LoadError => err
warn "Couldn't load awesome_print: #{err}"
endNothing too fancy here. Just some require commands and initialization to load up some of my favorite and frequently used gems.
# configure irb
IRB.conf[:PROMPT_MODE] = :SIMPLE
# irb history
ARGV.concat [ "--readline", "--prompt-mode", "simple" ]
IRB.conf[:EVAL_HISTORY] = 1000
IRB.conf[:SAVE_HISTORY] = 1000
IRB.conf[:HISTORY_FILE] = File::expand_path("~/.irbhistory")Prompt mode simple just makes prompts look like >> instead of 1.9.3p327 :001 >
Command history is obviously supremely useful if you frequently use the console to hack out solutions.
# load .irbrc_rails in rails environments
railsrc_path = File.expand_path('~/.irbrc_rails')
if ( ENV['RAILS_ENV'] || defined? Rails ) && File.exist?( railsrc_path )
begin
load railsrc_path
rescue Exception
warn "Could not load: #{ railsrc_path } because of #{$!.message}"
end
endAhh, now things get interesting. If we detect RAILS_ENV or the Rails object is defined then we can assume that we’re actually inside a Rails console and add some extra configuration. We’ll get to that extra configuration for Rails in a moment.
class Object
def interesting_methods
case self.class
when Class
self.public_methods.sort - Object.public_methods
when Module
self.public_methods.sort - Module.public_methods
else
self.public_methods.sort - Object.new.public_methods
end
end
endThis one is pretty fun. It adds on a method to Object called interesting_methods. Ruby’s object model is great, but it means that the public api to any object is full of methods defined up its ancestor chain.
>> Object.new.methods.count
71
>> Module.new.methods.count
111
>> Class.new.methods.count
115interesting_methods gives us an easy way to filter all that out.
class Magic
def cast
'poof'
end
end
>> Magic.new.methods.count
72
>> Magic.new.interesting_methods.count
1
>> Magic.new.interesting_methods
[
[0] :cast
]Handy! And with some introspection that code accounts for module and class methods as well.
Loading an rc file just for the Rails console adds all kinds of opportunities for enhancement.
# hirb: some nice stuff for Rails
begin
require 'hirb'
HIRB_LOADED = true
rescue LoadError
HIRB_LOADED = false
end
require 'logger'
def loud_logger
enable_hirb
set_logger_to Logger.new(STDOUT)
end
def quiet_logger
disable_hirb
set_logger_to nil
end
def set_logger_to(logger)
ActiveRecord::Base.logger = logger
ActiveRecord::Base.clear_reloadable_connections!
end
def enable_hirb
if HIRB_LOADED
Hirb::Formatter.dynamic_config['ActiveRecord::Base']
Hirb.enable
else
puts "hirb is not loaded"
end
end
def disable_hirb
if HIRB_LOADED
Hirb.disable
else
puts "hirb is not loaded"
end
end
def efind(email)
User.find_by_email email
end
# set a nice prompt
rails_root = File.basename(Dir.pwd)
IRB.conf[:PROMPT] ||= {}
IRB.conf[:PROMPT][:RAILS] = {
:PROMPT_I => "#{rails_root}> ", # normal prompt
:PROMPT_S => "#{rails_root}* ", # prompt when continuing a string
:PROMPT_C => "#{rails_root}? ", # prompt when continuing a statement
:RETURN => "=> %s\n" # prefixes output
}
IRB.conf[:PROMPT_MODE] = :RAILS
# turn on the loud logging by default
IRB.conf[:IRB_RC] = Proc.new { loud_logger }Note, for these enhancements to work in Rails apps that use bundler you’ll need to add the required gems to your Gemfile and then run bundle.
group :development do
gem "awesome_print"
gem "hirb"
gem "interactive_editor"
endHirb is an awesome thing to add to your Rails console. It adds stuff like table formatting for models and general data, a console menu, and a pager.
The logger customizations will output things like SQL statements made to the database unless quiet_logger is called. Very handy if you are debugging a complex ActiveRecord query.
The prompt mode configuration is just a nice prompt with the application name. We define a :RAILS prompt mode and then use it.
That efind method is just a handy shortcut for something I do semi-often. It combines well with a dash expander shortcut that autofills in my email address.
There’s a great post on tagholic with tons of info on how to completely customize your irb session: Exploring how to configure irb. If you’re interested in any of the options I use in this post, odds are good that they are explained in much more detail there.
