即使记录也存在，如何为.save（）返回成功？ — Rails 3.1

Question

I'm trying to modify the following code to make it return the flash notice and success if the email exists.

class SubscribersController < ApplicationController
  respond_to :json

  def create
    @subscriber = Subscriber.new(:first_name     => params[:first_name],
                                 :last_name      => params[:last_name],
                                 :email          => params[:email],
                                 :ip_address     => request.remote_ip,
                                 :referring_page => request.referer )
    if @subscriber.save
      flash[:notice] = "You've been subscribed!"
    end

    respond_with(@subscriber)
  end

end

How could I check if the email address exists already and return success with the flash message?

I don't want to throw an error if the email already exists (which the model checks for) -- I want to still say you've been subscribed.

I've tried checking with .present? but it throws an error:

<h1>
  NoMethodError
    in SubscribersController#create
</h1>
<pre>undefined method `model_name' for ActiveRecord::Relation:Class</pre>

Answer 1

I believe, you could use a dynamic finder for this matter.

@subscriber = Subscriber.find_or_initialize_by_email(params[:email], { :first_name => ..., })

however, I think, saving a persisted record will return false , so you need to check if

@subscriber.persisted? or @subscriber.save
  flash[:success] = "You've been subscribed!"
end

Answer 2

Add a validation in de subscriber model

validates_uniqueness_of :email

and in the controller

@subscriber.valid?

if @subscriber.errors.on(:email) == "XXX"
   flash[:error] = "email address exists already"
end