Ruby on Rails

Rails relationships that is 

 

I am doing something wrong, and can't figure out what and where.

 

I have 3 models - Command, Contact, and a joined CommandsContact via has_many through relationship, because commands_contacts table holds an extra column - notification_type, which could be either set to host of service. 

 

Models 

 

contact.rb

 

This one is a special case, because it has 2 extra "virtual" relationships :host_notification_commands and :service_notification_commands, which gives me an ability to selectively get either host or service commands for a user (contact) like this:

 

Contact.first.host_notification_commands or 

Contact.find(3).service_notification_commands etc.

class Contact < ActiveRecord::Base     has_many :commands_contacts, :inverse_of => :contact   has_many :commands, :through => :commands_contacts     has_many :host_notification_commands, -> { where commands_contacts: { :notification_type => 'host' } },            :through => :commands_contacts,            :class_name => 'Command',             :source => :command     has_many :service_notification_commands, -> { where commands_contacts: { notification_type: 'service' } },            :through => :commands_contacts,            :class_name => 'Command',             :source => :command     accepts_nested_attributes_for :host_notification_commands   accepts_nested_attributes_for :service_notification_commands    end

command.rb

class Command < ActiveRecord::Base      has_many :commands_contacts, :inverse_of => :command    has_many :contacts, :through => :commands_contacts      accepts_nested_attributes_for :commands_contacts    end

commands_contracts.rb

class CommandsContact < ActiveRecord::Base     belongs_to :command   belongs_to :contact     accepts_nested_attributes_for :command   accepts_nested_attributes_for :contact    end

So far. So good. This works as expected (i think?) as I am able to manually create relationships, as long as i have a contact and a command already. 

contact = Contact.first  command = Command.find(7)  contact.host_notification_commands << command

Aaand after this things start to go down south, because a Controller, strong_parameters and accepts_nested_attributes_for come into play, and this is where I fail. 

 

My assumption is that Rails will be able to handle this for me and establish the relationship, right? 

def create    contact = Contact.new safe_params    contact.save  end

Because I use accepts_nested_attributes_for, I have to append _attributes to the names of nested objects, right? So i do a simple re-assignment here and then permit them with strong_parameters.

private  def safe_params      params[:contact][:host_notification_commands_attributes] = params[:contact][:host_notification_commands]    params[:contact][:service_notification_commands_attributes] = params[:contact][:service_notification_commands]        params.require(:contact)        .permit(:contact_name,           :host_notification_commands_attributes => [ :id, :command_name, :command_line, :command_description ],          :service_notification_commands_attributes => [ :id, :command_name, :command_line, :command_description ])

 

 

As far as I understand, this is all that needs to be done and Rails should handle the rest, right? The problem is that it does not even try to to establish a relationship. It does a SELECT and immediately fails.

 

When I try to create a new record, it fails with:

 

ActiveRecord::RecordNotFound (Couldn't find Command with ID=1 for Contact with ID=):

Because it hasn't yet created a user a hasn't established a relationship. 

 

When I try to edit and existing contact and establish a relationship with existing command, it fails with

 

   (0.1ms)  BEGIN

  Command Load (0.2ms)  SELECT `commands`.* FROM `commands` INNER JOIN `commands_contacts` ON `commands`.`id` = `commands_contacts`.`command_id` WHERE `commands_contacts`.`contact_id` = 3 AND `commands_contacts`.`notification_type` = 'host' AND `commands`.`id` = 1

   (0.1ms)  ROLLBACK

Completed 404 Not Found in 6ms

 

ActiveRecord::RecordNotFound (Couldn't find Command with ID=1 for Contact with ID=3):

 

Uhm... Of course this relationship record is not found. I am trying to create it! Why does it run SELECT instead of UPDATE / INSERT ?

 

 

So, something tells me I have this relationship defined incorrectly somewhere in my models.... but where? How do i troubleshoot this?