CODEWITHSUNDEEP
ruby-on-rails
user1781472
user1781472

Reputation: 517

rails get method name from string and then pass arguments

Folks,

I have a config/settings.yml file that looks like this:

lab_options: mappings_hash: {can_type: "Tumor::OncologyRun.basic_test"}

then in my model app/models/tumor.rb I wanted to do something like this

def sync_tumor_test
  Settings.lab_options.mappings_hash.to_hash[:can_type](age, demographic)
end

In the above case I want to call the method Tumor::OncologyRun.basic_test with arguments age and demographics. The method Tumor::OncologyRun.basic_test is present in lib/tumor/oncology_run.rb and looks like this:

    module Tumor
     module OncologyRun
      def OncologyRun.basic_test(age, demographics)
       #code here
      end
     end
   end

I know that in ruby method names are strings, so how do I call this with arguments, when I am trying this from the rails console with something like send(Settings.lab_options.mappings_hash.to_hash[:can_type](age, demographic)) I get a NOMethod Error any feedback is much much appreciated, thanks a lot

Upvotes: 0

Views: 455

Answers (1)

Dave S.
Dave S.

Reputation: 6419

In this case you're storing both the object name and the method call in a single string, so first you have to break them up, then use send, like so:

klass, meth = Settings.lab_options.mappings_hash.to_hash[:can_type].split('.')
klass.constantize.send(meth.to_sym, age, demographic)

The above should be equivelant to calling Tumor::OncologyRun.basic_test(age, demographic). The constantize call is necessary to convert from the name of the object into the actual ruby object.

Note - this assumes that basic_test is a class method on OncologyRun. If it's an instance method, you'll need to call new first and then use the send call on the resultant object.

Upvotes: 1

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