I'm having trouble initializing instance variables in Rails, need to use a variable in different methods, but this needs to be initialized beforehand, eg:
class Test < ActiveRecord::Base
@test = 1
def testing
@test+1
end
end
t = Test.new
t.testing
I get the follow error:
test.rb:4:in `testar': undefined method `+' for nil:NilClass (NoMethodError)
from test.rb:9:in `<main>'
Is there a more elegant way to initialize a variable without using the after_initialize?:
So after_initialize seems to be really the best solution.
class Test < ActiveRecord::Base
after_initialize do
@test = 1
end
def testing
@test+=1
end
end
@test += 1 if you actually want to modify it.If you really dont want to use after_initialize, create the variable on the fly:
attr_writer :test
def testing
self.test += 1
end
def test
@test ||= 0
end
@-style instance variables when writing model code.||=. Once you have that, the @test variable should not be used directly is all I'm saying.What you've defined in your code is a @test class instance variables, and you probably wanted just an instance variable.
Using after_initialize is overkill here, you can do something like:
def test
@test ||= 1
end
attr_writer
initialize, invoked onnew)?after_initializeis the way to go@test = 1hasselfpointing to your class, not to your instance.