ruby-on-railsactiverecordrails-flash

Accessing rails flash[:notice] in a model


I am trying to assign a message to flash[:notice] in a model observer.

This question has already been asked: Ruby on Rails: Observers and flash[:notice] messages?

However, I get the following error message when I try to access it in my model:

undefined local variable or method `flash' for #<ModelObserver:0x2c1742c>

Here is my code:

class ModelObserver < ActiveRecord::Observer
  observe A, B, C

  def after_save(model)
    puts "Model saved"
    flash[:notice] = "Model saved"
  end
end

I know the method is being called because "Model saved" is printed to the terminal.

Is it possible to access the flash inside an observer, and if so, how?


Solution

  • I needed to set flash[:notice] in the model to override the generic "@model was successfully updated".

    This what I did

    1. Created a virtual attribute in the respective model called validation_message
    2. Then I set the virtual attribute in the respective model when needed
    3. Used an after_action when this virtual attribute was not blank to override the default flash

    You can see my controller and model how I accomplished this below:

    class Reservation < ActiveRecord::Base
    
      belongs_to :retailer
      belongs_to :sharedorder
      accepts_nested_attributes_for :sharedorder
      accepts_nested_attributes_for :retailer
    
      attr_accessor :validation_code, :validation_messages
    
      validate :first_reservation, :if => :new_record_and_unvalidated
    
      def new_record_and_unvalidated
        if !self.new_record? && !self.retailer.validated?
          true
        else
          false
        end
      end
    
      def first_reservation
        if self.validation_code != "test" || self.validation_code.blank?
          errors.add_to_base("Validation code was incorrect") 
        else
          self.retailer.update_attribute(:validated, true)
          self.validation_message = "Your validation is successful and you will not need to do that again"
        end
      end
    end
    
    class ReservationsController < ApplicationController
    
      before_filter :authenticate_retailer!
      after_filter :validation_messages, :except => :index
    
      def validation_messages
        return unless @reservation.validation_message.present?
    
        flash[:notice] = @reservation.validation_message
      end
    end
    

    One possible refactor would be to move the actual message in a proper file (e.g. a locale) and pass to validation_message only the proper key.

    Should you need more than one notice it's easy enough to turn validation_message into an array or a hash and call it validation_messages instead.