Question

How do I make a dynamic variable name/object?

I have a polymorphic model for sending request and joining models together upon approval.
Example a user can join a company, project or group ect.

so I have a profiles model that belongs_to various models, but I only want the relationship to be built once a request is accepted.

profile.rb

class Profile < ActiveRecord::Base
    belongs_to :user
    belongs_to :company
    has_many :requests
    has_many :requested, as: :requestable

    attr_accessible :first_name, :last_name


    validates :first_name, presence: true
    validates :last_name, presence: true

end

I need my controller to be able to apply its actions based on the model that it is dealing with.

I was hoping that with @profile.@belongs_to would be the same as @profile.company which in this case would be nill. Then from there @profile.@belongs_to = @requestable

because the profile is always going to belong_to the model it joins @belongs_to will always be the model name in lowercase.

I have been messing around with the contents of objects posted to a flash message, to try and figure this out.

requests_controller.rb

class RequestsController < ApplicationController
 before_filter :load_requestable
     def accept
        @request = Request.find(params[:id])
        @profile = Profile.find(@request.profile.id)

        redirect_to [@requestable, :requests], notice: "#{@profile.@belongs_to} #{@request.profile.first_name} #{@request.profile.last_name} id: #{@request.profile.id} wants to join #{@requestable.name}  id: #{@requestable.id}"
     end

     private

     def load_requestable
       klass = [Company, Profile].detect { |c| params["#{c.name.underscore}_id"]}
       @requestable = klass.find(params["#{klass.name.underscore}_id"])
       @belongs_to = klass.to_s.downcase
    end
 end

I have played around in the console with somthing along the lines of:

profile = Profile.first
profile.company = Company.first 

and this creates the join in the object which can then be saved.

Answer 1

If @belongs_to contains your association you can simple call @profile.send(@belongs_to) or in case of an assignment @profile.send("#{@belongs_to}=",@requestable)

#send allows you to send any message to any object in ruby. Think dynamic method invocation.

And you should be done