Question

I’ve a mongoid model and method like the following :

class Category
  include Mongoid::Document
  field :name, :type => String
  ...

  def self.custom_find
    ...
    Str = Struct.new(:arg1, :arg2)
    array << Str.new(one, two)
    ...
  end
end

and I get the following error :

dynamic constant assignment (SyntaxError)
    Str = Struct.new(:arg1, :arg2)

I tried moving Str = Struct.new(:arg1, :arg2) into config/initializers/categories.rb but then I get :

BSON::InvalidDocument in TrendsController#index

Cannot serialize an object of class Category into BSON.

by removing the custom_find offending method, everithing else works fine, then I guess is something related to "Struct".

Any idea ?

Answer 1

You can work around dynamic constant assignment error in several ways:

array = Struct.new(:arg1, :arg2).new(one, two)

or

Object.const_set :Str, Struct.new(:arg1, :arg2)
Str # => Str

This shouldn’t solve serialization problem, though.