module Karafka::Helpers::ConfigRetriever
A helper method that allows us to build methods that try to get a given attribute from its instance value and if it fails, will fallback to the default config or config.kafka value for a given attribute. It is used to simplify the checks. @note Worth noticing, that the value might be equal to false, so even
then we need to return it. That's why we check for nil?
@example Define config retried attribute for start_from_beginning class Test
extend Karafka::Helpers::ConfigRetriever config_retriever_for :start_from_beginning
end
Test.new.start_from_beginning #=> false test_instance = Test.new test_instance.start_from_beginning = true test_instance.start_from_beginning #=> true
Public Instance Methods
config_retriever_for(attribute)
click to toggle source
Builds proper methods for setting and retrieving (with fallback) given attribute value @param attribute [Symbol] attribute name based on which we will build
accessor with fallback
# File lib/karafka/helpers/config_retriever.rb, line 25 def config_retriever_for(attribute) attr_writer attribute unless method_defined? :"#{attribute}=" # Don't redefine if we already have accessor for a given element return if method_defined? attribute define_method attribute do current_value = instance_variable_get(:"@#{attribute}") return current_value unless current_value.nil? value = if Karafka::App.config.respond_to?(attribute) Karafka::App.config.send(attribute) else Karafka::App.config.kafka.send(attribute) end instance_variable_set(:"@#{attribute}", value) end end