Callbacks in aasm gem and ActionMailer - ruby-on-rails

Question

Im learning ruby on rails and have a trouble with aasm callbacks and actionmailer.
I have a hotels model. Heres a code:
class Hotel < ActiveRecord::Base
include AASM
scope :approved_hotels, -> { where(aasm_state: "approved") }
has_many :comments
belongs_to :user, :counter_cache => true
has_many :ratings
belongs_to :address
aasm do
state :pending, initial: true
state :approved
state :rejected
event :approve, :after => :send_email do
transitions from: :pending, to: :approved
end
event :reject, :after => :send_email do
transitions from: :pending, to: :rejected
end
end
def send_email
end
end
As you see user has to get email when state of the hotel he added was changed. Heres what i wrote but its not THE solution cos user gets emails every time admin updates hotel with "pending" state.
class HotelsController < ApplicationController
before_filter :authenticate_user!, except: [:index, :show, :top5hotels]
def update
#hotel = Hotel.find(params[:id])
if #hotel.aasm_state == "pending"
#hotel.aasm_state = params[:state]
UserMailer.changed_state_email(current_user, #hotel.name,
#hotel.aasm_state).deliver
end
if #hotel.update_attributes!(params[:hotel])
redirect_to admin_hotel_path(#hotel), notice: "Hotel was successfully updated."
else
render "edit"
end
end
end
So i think i need to use callback but i dont know how to call
UserMailer.changed_state_email(current_user, #hotel.name,
#hotel.aasm_state).deliver
from the model.
I tried
UserMailer.changed_state_email(User.find(:id), Hotel.find(:name),
Hotel.find(aasm_state)).deliver
but that doesnt work.
Im really out of options and looking for any help.
Thanks!
UPDATE 1:
Thank to Amit Sharma! I`ve made these changes and now getting
NoMethodError: undefined method `email' for nil:NilClass
Looks like user object Im passing to changed_state_email() method is nill but I have no idea why.
Here is my mailer file aswell:
class UserMailer < ActionMailer::Base
default from: "localhost"
# Send email to user when hotels state change
def changed_state_email(user, hotel_name, current_state)
mail(to: user.email, subject: 'State of your hotel '+hotel_name+'has been
changed to '+current_state)
end
end
Here is a result of puts "====#{self.inspect}":
====#<Hotel id: nil, name: "CoolName", breakfast: nil, room_description: nil, price_for_room: 34, star_rating: 3, user_id: nil, address_id: nil, created_at: nil, updated_at: nil, average_rating: nil, photo_file_name: nil, photo_content_type: nil, photo_file_size: nil, photo_updated_at: nil, aasm_state: "approved">
F.====#
F.====#
UPDATE 2:
It returns user object. Output from the console:
1.9.3-p551 :006 > h = Hotel.find(1)
Hotel Load (0.4ms) SELECT "hotels".* FROM "hotels" WHERE "hotels"."id" = ? LIMIT 1 [["id", 1]]
=> #<Hotel id: 1, name: "QWERTYUI", breakfast: nil, room_description: nil, price_for_room: 44, star_rating: 4, user_id: 2, address_id: nil, created_at: "2015-05-30 22:55:01", updated_at: "2015-05-30 22:55:01", average_rating: nil, photo_file_name: nil, photo_content_type: nil, photo_file_size: nil, photo_updated_at: nil, aasm_state: "pending">
1.9.3-p551 :007 > h
=> #<Hotel id: 1, name: "QWERTYUI", breakfast: nil, room_description: nil, price_for_room: 44, star_rating: 4, user_id: 2, address_id: nil, created_at: "2015-05-30 22:55:01", updated_at: "2015-05-30 22:55:01", average_rating: nil, photo_file_name: nil, photo_content_type: nil, photo_file_size: nil, photo_updated_at: nil, aasm_state: "pending">
1.9.3-p551 :008 > h.user
User Load (0.2ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 2]]
=> #<User id: 2, name: "qwerty", email: "qweqweqweqwe#qwe.com", encrypted_password: "$2a$10$FG5xXb/9wYLcdsCrfJtuDOTsslyY8p.m0qkbP4a5OEvJ...", reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil, sign_in_count: 0, current_sign_in_at: nil, last_sign_in_at: nil, current_sign_in_ip: nil, last_sign_in_ip: nil, admin: false, created_at: "2015-05-30 22:54:14", updated_at: "2015-05-30 22:54:14", comments_count: 0, hotels_count: 1>

Answer 1

You can Try this. I hope this will help you.
In Hotels Controller.
class HotelsController < ApplicationController
before_filter :authenticate_user!, except: [:index, :show, :top5hotels]
def update
#hotel = Hotel.find(params[:id])
if #hotel.pending?
if params[:state] == "approved"
#hotel.approved!
elsif params[:state] == "rejected"
#hotel.rejected!
end
end
if #hotel.update_attributes!(params[:hotel])
redirect_to admin_hotel_path(#hotel), notice: "Hotel was successfully updated."
else
render "edit"
end
end
end
In Hotel model.
def send_email
user = self.user
puts "====#{self.inspect}===#{user.inspect}"
UserMailer.changed_state_email(user, self.name,
self.aasm_state).deliver
end
Please revert back to me if you face any issue.