I'm trying to use y object
in Rails 3.2.6/Ruby 1.9.3 console to get nicely formatted yaml output for an ActiveRecord object, but for some reason it isn't working for me. I've used it in the past, but somewhere along the way it broke. I get the following output when I try:
NameError: undefined local variable or method `yaml' for main:Object
The y
method is actually an extension to the Kernel
object put in place by the Syck YAML parser/emitter. Here are the last few lines of lib/ruby/1.9.1/syck.rb
:
module Kernel
def y( object, *objects )
objects.unshift object
puts( if objects.length == 1
YAML.dump( *objects )
else
YAML.dump_stream( *objects )
end )
end
private :y
end
By default, Ruby 1.9.3 uses the Psych parser/emitter instead of Syck (I can only presume they're pronounced differently), and Psych doesn't declare such a method.
If you really loved y
, you can simply use Syck instead of Psych in the console:
Loading development environment (Rails 3.2.5)
1.9.3p194 :001 > y 'hello'
NoMethodError: undefined method 'y' for main:Object
1.9.3p194 :002 > YAML::ENGINE.yamler = 'syck'
"syck"
1.9.3p194 :003 > y 'hello'
--- hello
nil
I'll also use this chance to plug awesome_print, which does for basically everything what y
does for YAML.
For rails 4/ruby 2 you could use just
puts object.to_yaml
来源:https://stackoverflow.com/questions/11571801/rails-console-y-helper-returns-nameerror-rather-than-yaml-formatting-output