Rails Conditional Routing

rails.rb

# Conditional Routing in Rails
# Send requests matching the same path to different controller actions based on information in the request
# http://bjedrocha.com/rails/2015/03/18/role-based-routing-in-rails/

class ThingsConstraint
  def initialize(*names)
    @matches = names
  end

  def matches?(request)
    user_name, _ = ActionController::HttpAuthentication::Basic.user_name_and_password(request)
    @matches.include?(user_name)
  end
end

# config/routes.rb
resources :things, :path => 'things', :only => [] do
  member do
    # routes to new_things#doit if the constraint evaluates to true
    post :doit, constraints: ThingsConstraint.new('jane'), to: 'new_things#doit'
    # routes to the original controller action if previous route did not match
    post :doit
  end
end

# Rails unhandled exception to error mappings are defined here:
Rails.configuration.action_dispatch.rescue_responses

# And processed via the ExceptionWrapper middleware
# https://github.com/rails/rails/blob/v5.1.6.1/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb

# Stop spring
spring stop

# validates that field is present
validate :field, presence: true
# validates that field is not present
validate :field, absence: true

# Disable ActiveRecord Callbacks

# disables all *save callbacks on all ModelClass instances
ModelClass._save_callbacks.each do |cb|
  ModelClass.skip_callback(cb.name, cb.kind, cb.filter)
end

# enables all *save callbacks on all ModelClass instances
ModelClass._save_callbacks.each do |cb|
  ModelClass.set_callback(cb.name, cb.kind, cb.filter)
end