CODEWITHSUNDEEP
ruby-on-rails
sja
sja

Reputation: 347

how to grab the correct User from a different model

I'm trying to calculate a conversion rate. However I've only been able to get it working using

User.first

however I don't really want the first user, as my app can have many. I want the specific user that is currently signed in to be that user.

Here's how the conversion rate method looks (campaign belongs to user):

campaign.rb 

def conversion_rate
  fav = self.favorites.where(favorited: true)
  val = fav.present? ? self.favorites.where(:owner_id => User.first.followers.map(&:follower_id)).count.to_f / fav.count.to_f * 100 : 0.0
  val
end

what's the right method after the User here in order to find the actual user?

Upvotes: 1

Views: 23

Answers (3)

Zoë Sparks
Zoë Sparks

Reputation: 340

Basically, you want to get the user's ID from the current session. The details of this will vary based on how you've implemented user authentication and so on, but in general when a user logs in they'll get a session ID from your application that will be stored locally in their browser and used to track their actions while logged in. This ID is generally accessible through something like session[:user_id] in your application, enabling you to get the currently-logged-in user through something like User.find(session[:user_id]). See http://guides.rubyonrails.org/security.html#sessions for more information on this. Also, if you're using an authentication library (like Devise or something), check in its documentation for information on how it handles sessions.

Upvotes: 0

zetetic
zetetic

Reputation: 47548

The conversion_rate method depends on a user. You can pass that into the method as an argument:

def conversion_rate(user)
  fav = self.favorites.where(favorited: true)
  val = fav.present? ? self.favorites.where(:owner_id => user.followers.map(&:follower_id)).count.to_f / fav.count.to_f * 100 : 0.0
  val
end

Then it is only a matter of getting the currently logged in user. This depends on your application, but a typical Rails app has a current_user method defined in ApplicationController. You would have to call the conversion_rate method at a point in your code where current_user is available, i.e. in a controller action.

Upvotes: 0

Sonalkumar sute
Sonalkumar sute

Reputation: 2575

So I think you have current_user in your application_controller

def current_user  
    @current_user ||= User.find(session[:user_id]) if session[:user_id]  
end

then this will be accessible in all controllers and views

So you can call @campaign.conversion_rate(current_user), and pass current_user

def conversion_rate(user)
    fav = self.favorites.where(favorited: true)
    val = fav.present? ? self.favorites.where(:owner_id => user.followers.map(&:follower_id)).count.to_f / fav.count.to_f * 100 : 0.0 val  
end

Upvotes: 1

Related Questions