Correct methods in Ruby on Rails model

Question

My Rails model has some bad lines. In general, first error is when accessing roles variable from has_access def. And then, second is when making where action.

class Organization < ActiveRecord::Base

  has_and_belongs_to_many :organizations_users
  belongs_to :user

  validates :name, :presence => true, :length => { minimum: 4, maximum: 35 }, uniqueness: true
  roles = { :administrator => 1, :support => 2 }

  def has_access(chosen_user, role)
      self.organizations_users.where('user_id = ? and role = ?', chosen_user.id, roles[role]).exists?
  end

  def add_user(chosen_user, role)
      if !self.has_access(chosen_user, role)
          self.organizations_users.create({user_id: chosen_user.id, role: roles[role]})
      end
      has_access(chosen_user,role)
  end

end

I need also to query over organizations_users table to get information about access. How can I fix that?

For where statement (2nd) is "undefined method `where' for #". For roles is undefined local variable or method `roles' for # — Haris Bašić, Jun 19 '14 at 19:07
What do you want to do? Explain what do you expect this method to do. — Jorge de los Santos, Jun 19 '14 at 19:12
I need to have method which will be accessible both within a class and on instance. I want those methods to return does user have access to organization and to add user to organization. — Haris Bašić, Jun 19 '14 at 19:13
Can't you turn that has_access into a scope? Then you would reference it as `!Organization.has_access(chosen_user, role)` — Tacoman667, Jun 19 '14 at 19:14
Something like `scope :has_access, lambda { |chosen_user, role| #something something.... }` — Tacoman667, Jun 19 '14 at 19:17
If you do User.first.method you always generating an instance of the user and has_access will work. — Jorge de los Santos, Jun 19 '14 at 19:22
Edit the question to explain what are you trying to do, this fails and pasting a piece of code is not enough to solve a question that changes on each solution. — Jorge de los Santos, Jun 19 '14 at 19:24
You want add_user to find the entry in the user_organizations table, or create one if it doesn't exist? — Jorge de los Santos, Jun 19 '14 at 19:36

Jorge de los Santos · Answer 1 · 2014-06-19T19:40:14.817

0

To find or add the organization do:

def has_access(role)
  self.organizations_user.find_or_create_by_role(role)
end

This allow you to use:

user = User.has_access("administrator")

user = User.first.has_acess("administrator")

And will do a find in the table user_organizations or create a new entry if can't find one. ActiveRecord relation will take care of the user_id

edited Jun 19 '14 at 19:40

answered Jun 19 '14 at 19:09

Jorge de los Santos

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But then it is not accessible like `user_access = User.first.has_access...` – Haris Bašić Jun 19 '14 at 19:10
That's because User.first is returning a single instance, and then you are trying to do a .where which is a Class method for arrays. – Jorge de los Santos Jun 19 '14 at 19:11
However, this self. doesn't work, tried it now. I need to have method which will be accessible both within a class and on instance – Haris Bašić Jun 19 '14 at 19:13
`def self.*` makes Organization.* class method. Think static methods in a statically compiled language. You cannot call self.*, you would have to call Organization.* – Tacoman667 Jun 19 '14 at 19:16
Try this as long as has access is a boolean. – Jorge de los Santos Jun 19 '14 at 19:20
Again mistake, I need to make a join on has_and_belongs_to_many table is has_access method. – Haris Bašić Jun 19 '14 at 19:22
What about this one, is this what you need? – Jorge de los Santos Jun 19 '14 at 19:40

score 0 · Answer 2 · answered Jun 19 '14 at 19:22

Simplest fix would be to change

def has_access(chosen_user, role)
  where('user_id = ? and role = ?', chosen_user.id, roles[role]).exists?
end

to:

def has_access(chosen_user, role)
  Organization.where('user_id = ? and role = ?', chosen_user.id, roles[role]).exists?
end

The reason for this is the where() method is a class method and only accessible from the class itself, IE. Organization.where. BTW, I am assuming (dangerously :) ) That this where clause is used from Organization.

Correct methods in Ruby on Rails model

2 Answers2