Soft-coding model names?

rubyonrails-talk
1

Hello.

I am trying to "soft-code" the model names in my app so I can use a generic method call to achieve some results. Many of my modules have the the following method:

def ModelName.get_array   # same code goes here for every module and it returns an array. end

Is there a way to replace the model name with a variable or something else in such a way that the method can be called in a generic way? Something like:

my_array = @model_name.get_array

Thanks.

Pepe

2

Hello.

I am trying to "soft-code" the model names in my app so I can use a generic method call to achieve some results. Many of my modules have the the following method:

def ModelName.get_array # same code goes here for every module and it returns an array. end

Is there a way to replace the model name with a variable or something else in such a way that the method can be called in a generic way? Something like:

my_array = @model_name.get_array

Take a look at constantize: http://api.rubyonrails.com/classes/ActiveSupport/CoreExtensions/String/Inflections.html#M000488

You should be able to do something like this @model_name.constantize.get_array

3

This might be better written as class level methods then and mixed at the class level. Here's an example of how that would work:

module Foo   def self.included(base)     base.extend ClassLevelMethods   end

  # You can still just define instance level methods as normal   def bar     # ...   end

  # But now these methods will be mixed in at the class level   module ClassLevelMethods     def baz       # ...     end   end end

and just include Foo as normal. HTH

RSL

4

Thanks for the tip. I have tried 'constantize' with variables and it worked like a charm. I'll try it with my models and see how it works.

Do you know how to do something similar with variables? I have a page with a table of 31 rows and all the field names follow the format 'field_namexx' where 'xx' is a sequence number. I have tried constantize with regular variables but it only works with... constants! Go figure! :slight_smile:

Thanks a lot.

Pepe

5

Thanks Russell. I understand (or almost) what you have in mind. It would probably be the the 'right' way to do it. I'll play with it and see what I can come up with.

Thanks a lot.

Pepe