Ruby Is Already Using the Class Name of My Model

Ruby is already using the class name of my model

Some possibilities:

• avoid the require 'monitor.rb' call which is pulling in the standard Monitor instance
• do some runtime magic to rename the existing Monitor class.
• monkey with your load path so that require 'monitor.rb' pulls in an empty implementation of Monitor.

But in all cases you could end up with the situation where a 3rd party library is using Monitor expecting it to be the standard Monitor class. So, I'd advise against any of the above.

I'd say your only two reasonable options are:

A) you could put your class in a namespace:

Module MyApp
  class Monitor
    #...
  end
end

if your app uses some kind of auto-require magic (e.g it's a rails app) then you would put your implementation in /my_app/monitor.rb. When you wanted to refer to that class you would do something like my_monitor = MyApp::Monitor.new(), or whatever.

B) you could use a different class name :)

Ruby 2.4 module name conflict with my model class name

Warning module is used for overriding ruby warn method. To temporarily get around the error - you can undefine the constant before defining your model:

Object.send(:remove_const, :Warning)

runnable test:

require "bundler/inline"
gemfile(true) do
  source "https://rubygems.org"
  gem "activerecord", "5.2.3"
  gem "sqlite3", "~> 1.3.6"
end

require "active_record"
require "minitest/autorun"
require "logger"

ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Schema.define do
  create_table(:warnings, force: true){|t| t.string  :name }
end

RubyWarning = Warning
Object.send(:remove_const, :Warning)

class Warning < ActiveRecord::Base
end

def RubyWarning.warn(str)
  puts "still works: #{str}"
end

class SomeTest < Minitest::Test
  def test_stuff
    wrn = Warning.create name: 'test'
    assert_equal(wrn.name, 'test')
    warn "Test warn"
  end
end

How to define the name of my model class in my case?

You can use the NumberUpdate model class to better reflect Rails conventions.

class NumberUpdate < ActiveRecord::Base
  ...
end

and

create_table :number_updates do
  ...
end

How to fix duplicated model name with using gem

As you said, since they are ActiveRecord classes, they have the same table and they will collide in the namespace of your application.

You can use Modules to avoid the name class collision, or you can update either the gem or your code to use a different name for the class.

If you choose to put your classes within a Module, for the table son the database, you can use set_table_name to use a different name for that class instead of the default one expected by ActiveRecord.

Rails cannot find model with same name as Ruby class

Don't name it Set. That way lies madness.

The deal is that defining the class fails because you're trying to redefine 'Set' which is already defined in the global context.

class Set < ActiveRecord::Base # You are attempting to define a constant 'Set'
                               # here, but you can't because it already exists

You can put your class in a module, and then you won't get the error because you'll be defining Set within a namespace.

module Custom
  class Set < ActiveRecord::Base
  end
end

However, every single time you want to use your Set class, you'll have to refer to it as Custom::Set. A lot of Rails magic won't work because it's expecting class names to be defined in the global context. You'll be monkeypatching plugins and gems left and right.

Far easier to just give it a different name.

class CustomSet < ActiveRecord::Base

All the magic works, and no monkeypatching required.

How do I use a model that has the same name as a gem?

You can't. A module and class of the same name cannot exist at the top-level namespace. If you actually did get Rails to load your Stripe module, your app would crash with a type error, complaining that you've tried to change the type of Stripe from module to class.

Name is already used or reserved by Ruby on Rails?

You may not create a model with the same name as the Application because it will create conflicting names. When you create an application i.e. rails new Education it will create a module named Education as follows

module Education
  class Application < Rails::Application
  #....
  end
end

This named module is then called in files such as config.ru, routes.rb and environment.rb and many more. So if you were able to create a model class by the same name it would create ambiguity as to whether you were calling the Model or the Module.

Rails: How to get the model class name based on the controller class name?

This will do it:

class HouseBuyersController < ApplicationController

  def index
    @model_name = controller_name.classify
  end

end

This is often needed when abstracting controller actions:

class HouseBuyersController < ApplicationController

  def index
    # Equivalent of @house_buyers = HouseBuyer.find(:all)
    objects = controller_name.classify.constantize.find(:all)
    instance_variable_set("@#{controller_name}", objects)
  end

end

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