ruby on rails - Dynamically created method? _one_time_conditions_valid_718? -

ruby on rails - Dynamically created method? _one_time_conditions_valid_718? -

i'm new ror , jumping big ror project. used railroady create diagram of of models , controllers. i've noticed many of controllers begin many 5 methods in form

_one_time_conditions_valid_xxx?

where xxx ranges 200 1116. however, these methods don't appear in actual code. these methods automagically generated gem? can't find reference anywhere.

okay here reference. these methods defined in activesupport::callbacks::callback in method called #_compile_per_key_options line 159. looks this

def _compile_per_key_options key_options = _compile_options(@per_key) @klass.class_eval <<-ruby_eval, __file__, __line__ + 1 def _one_time_conditions_valid_#{@callback_id}? true if #{key_options} end ruby_eval end

it used supplying info before, after , around filters through 2 different methods called #start , #end.

both #start , #end check these methods so

return if key && !object.send("_one_time_conditions_valid_#{@callback_id}?")

from looks whole purpose of these methods determine if callback been defined , if compile appropriate hooks.

these hooks clear names. before hooks run before defined action , access info before action gets it, after hooks run after defined action , access info after action gets it, , around hooks wrap action , triggers event yield. can define own such as:

class record include activesupport::callbacks define_callbacks :magic def magic run_callbacks :magic puts "abracadabra" end end end class magician < record set_callback :magic, :before, :perform def perform puts "the magician perform trick" end set_callback :magic, :after |object| puts "tada" end end

this shown

magician = magician.new magician.magic #output: # magician perform trick #(before callback) # abracadabra #(actual event) # tada #(after callback)

this means if controllers have "as many five" of these there equal amount of filters in form of before_filter, after_filter, before_action, around_action, etc. (the list of available callbacks pretty long)

ruby-on-rails ruby validation