#364 Active Record Reputation System

I don't know what makes this gem different from the existing acts_as_votable gem https://github.com/ryanto/acts_as_votable?

Thanks for the episode!

Is there a best practice for leaving room for new "haikus" to still have a shot at appearing at the top?

Would it be a good idea to prepend @haikus in the index action with a few of the more recently created haikus?

Great episode as always.
I found we can apply this from-scratch solution to implement facebook-like 'Like' button. Or is there any gem to do this already?

It's worth noting that sorting things by positive votes - negative votes is not usually what you want to sort by.

Just a note (although it's already mentioned in the episode): The code of the voted_for? method is inefficient. The problem is that it actually instantiates an ActiveRecord object which, in this case, is rather unnecessary.

Instead of this

def voted_for?(haiku)
  evaluations.where(target_type: haiku.class, target_id: haiku.id).present?
end

you should use the exists? method:

def voted_for?(haiku)
  evaluations.exists?(target_type: haiku.class, target_id: haiku.id)
end

If you are using scopes or something like that, you can also suffix it to a relation:

def voted_for?(haiku)
  evaluations.where(target_type: haiku.class, target_id: haiku.id).exists?
end

In both cases, rather than instantiating an ActiveRecord object, it would just call the connection's select_value which is way more efficient.

Side note: The exists? and its sibling any? are also helpful for use cases where you want to render a collection or, if it's empty, show the user a message like "No comments yet" or whatever.

I've taken the concept of if a user has voted for something and taken it a step further. The user can see if they have up voted something or down voted something.

        def up_voted_for?(item)
                  eval = evaluations.where(target_type: item.class, target_id: item.id).first
                  eval.present? && eval.value > 0 ? true : false
        end

        def down_voted_for?(item)
                  eval = evaluations.where(target_type: item.class, target_id: item.id).first
                  eval.present? && eval.value < 0 ? true : false
        end

This came in handy when I was checking to see if the user has up voted or not so I could change the image.

      <% if can? :vote, answers %>
        <% if current_user.up_voted_for?(answers) %>
          <%= image_tag("color_up_arrow.png") %>
        <% else %> 
          <%= link_to image_tag("gray_up_arrow.png"), vote_answer_path(answers, type: "up"), method: "post" %>
        <% end %>
      <% end %>

I've also used cancan to limit the user from voting on their own Answer/Question/Post.

      can [:new, :create], Answer
      can :manage, Answer, :user_id => user.id
      can :vote, Answer
      cannot :vote, Answer, :user_id => user.id

How would this work with other query parameters such as searches or paging? It seems that a simple search parameter added to the model is not recognized after the find_with_reputation call.

hi i followed all the tutorial but when i wanna show the links to vote, it says that function can't accept my voteable model as parameter...maybe it's compulsory that user is the creator of the voteable model? in my app the admin creates voteable resources, the user creates other kind of resources...could someone help me?

I'm wondering if it's possible with this gem to sort by the reputation table (RSEvaluation) only objects that have certain properties, such as created_at > 1.day.ago? Other voting systems offer a tally/query method, but with ar-rep-system I'm struggling to write similar functionality.

I was actually looking for a solution how to eagerly-load if the user voted on the answer, so that I can display a list of answers and tell if the user voted on them without doing the additional query.

I guess this could be done with some joins, but I wasn't able to do it with the activerecord-reputation-system.

Did anyone manage to do this?

Not working...

undefined method `add_evaluation' for nil:NilClass


Anyone know why the reputation system isn't providing this method?

my error when I'm trying to get total_votes:

PGError: ERROR:  relation "album_votes" does not exist

what's wrong?

Is it possible to use this to make a review system? For example: Have a five star rating system with comments/text belonging to each vote?

Hi Ryan,

I had a problem with your reputation-system-from-scratch, that all haikus with more than one vote were ordered as they had only one vote. I added the SUM() function to the by_votes class method to solve this. I also had to add group to the query to get more than one haiku. Without SUM() and group I got duplicate haikus.

def self.by_votes
  select('haikus.*, coalesce(SUM(value), 0) as votes').
  joins('left join haiku_votes on haiku_id=haikus.id').
  group('haikus.id').
  order('votes desc')
end

I have a Locations model with an belongs to association to my Areas model. The Areas model is setup with the Ancestry gem where I can build an arbitrary hierarchy of 'Areas' Say like this:

Main Area 1(id = 1)
- Sub Area 1.1 (id = 2)
-- Child Area 1.1.1 (id = 3)
-- Child Area 1.1.2 (id = 4)
- Sub Area 2 (id = 5)
-- Child Area 2.1 (id = 6)
-- etc...

So in my Locations model I have a area_id column and it's easy enough to call Locations.find(1).area.name = 'Child Area 1.1.2' and I can sort easy enough on this.

Now I have also created methods using ancestry functions in the Locations model to return the parent area's like this:

Locations.find(1).area_level_1 = 'Main Area 1'
Locations.find(1).area_level_2 = 'Sub Area 1.1'
Locations.find(1).area_level_3 = 'Child Area 1.1.2'

It's a bit of a hack but work except I can't sort on it. If I call Locations.all I can loop through and display a table etc. on a view and can create a sort function on the last child (i.e. area.name) but sorting based on area_level_1 fails. I am guessing there is an ugly manual SQL way to do this but I was hoping to perhaps find a more elegant way.

Where is really gets ugly is I am trying to leave the structure open enough where the area_id could only be 1 or 2 levels deep (i.e. id = 1 or id = 2 in my example data).

Excellent episode, hmm but how can I add some ajax to avoid reload the page when someone votes??

For accessing the total number of votes for a haiku, we need to use haiku.reputation_for(:votes) instead of haiku.reputation_value_for(:votes).

why does the line @haiku.add_or_update_evaluation(:votes, value, current_user) generate the error:

undefined local variable or method `user'

def vote
    value = params[:type] == "up" ? 1 : -1
    @haiku = Haiku.find(params[:id])
    @haiku.add_or_update_evaluation(:votes, value, current_user)
    redirect_to :back, notice: "Thank you for voting"
  end

application controller:

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

How can this be corrected?

Hey if you get: undefined method `reputation_value_for'

change `reputation_value_for' to 'reputation_for'

reputation_value_for was deprecated and replaced by reputation_for, see commit (10/03/2012)

reputation_for(reputation_name, *args)

https://github.com/twitter/activerecord-reputation-system/commit/552c04b0dead76cd79fb3915845b17b6a8de0cca

Also normalized_reputation_value_for was deprecated and replaced by normalized_reputation_for

normalized_reputation_for(reputation_name, *args)

Hey all, like @Mark says above, be sure to use reputation_value_for.

Also, the reputation system requires different names for all types of reputations (ie. users and haikus can't share the same reputation name), so the code from the example would be more like:

has_reputation :votes, 
               source: :user, 
               source_of: [{ :reputation: :user_votes, :of => :user }]
               aggregated_by: :sum

has_reputation :user_votes, 
               source: {reputation: :votes, of: :haikus],                    
               aggregated_by: :sum

I suppose that if you can decide the value of the evaluation, you could use this gem for rating 1-5 stars right? or would it be crazy?

Help me not working method voted for? After the user has voted

This a newbie question:

I am getting an error if the user is not logged in. How do you enforce signup if they want to vote, while still allowing them to look at the page if they haven't signed up?

Hi everyone, I'm trying this gem but I have different scenario. What I need this gem is for assign "points" for a "Employee" model, every-time when a "Manager" create "Job" entry. I have written a question on this on stackoverflow - appreciate if someone can help me out.

http://stackoverflow.com/questions/14556247/rails-reputation-system-for-a-content-management-system

I also have an issue, but with the SQL that is produced by the relationship between User and micropost (like haiku in the Railscast).
I posted it on stack overflow, would love it if someone could help.

Hi guys, I am very very new to ROR so I really appreciate any help.

When I place the

           has_reputation :votes, source: :user, aggregated_by: :sum

in my post model, my page shows up as

"undefined method `has_reputation' for #Class:0x007fe5708753e0"

and then reloading turns it into

"undefined method `key?' for nil:NilClass"

If I take away these codes in my post model, the page will show fine then I try to click on the "up" button, and this shows up

undefined method `add_evaluation' for #Post:0x007fe57100e2c8

anyone can help me out? thank you so much

this is my post_controller

def vote
value = params[:type] == "up" ? 1 : -1
@post = Post.find(params[:id])
@post.add_or_update_evaluation(:votes, value, current_user)
redirect_to :back, notice: "Thank you for voting"
end

Hi. I am trying to implement a reset voting feature. So when a user voted up and clicks again on thumbs up, the vote should be reset. I tried to delete evaluation but it does not work. Any clue or someone implement something similar?
Thanks

As much as I love Ryan and all the Railscasts, this one is a bit confusing, for this reason:

When Ryan talks about "reputation_value_for" (now "reputation_for") as giving him the "total number of votes," it is in fact giving him the SUM OF THE VOTE VALUES. So, if one is looking for the actual total number of votes, regardless of vote value, the returned value is incorrect.

In fact, as far as I can tell, there is no generic way to get the total number of votes on a model without assigning a constant "1" to a vote tally value and using reputation_for(:vote_tally). So, in order to end up with:

78% of 281 voters like this Haiku. You like it, too.

...there is a need to add a THIRD reputation to get the count of ReputationSystem::Evaluations on the Haiku model, since we need to use:

has_reputation :votes, source: :user, aggregated_by: :sum
has_reputation :avg_vote, source: :user, aggregated_by: :average

...in order to get the user's vote (assigned as 1 = like or 0 = unlike) as well as the average vote. So we add:

has_reputation :vote_tally, source: :user, aggregated_by: :sum

Then, in the vote action in the controller:

v_value = params[:type] == "up" ? 1 : 0
@haiku.add_or_update_evaluation(:votes, v_value, current_user)
@haiku.add_or_update_evaluation(:avg_vote, v_value, current_user)
@haiku.add_or_update_evaluation(:vote_tally, "1", current_user)

If there's an easier way to get the total number of votes on a model, I'd love to hear about it.

Any suggestions for how to implement caching of activerecord-reputation scores? Calculating these for each call creates a ton of overhead in my application.

Any idea for how to adapt user.voted_for? for a specific metric? I'm tracking up votes and down votes separately for comments in my app and would like to display a "toggled" look if a user has already voted.

This is my vote method on my comments controller:

def vote
  value = params[:type] == "up" ? 1 : -1
  @public_comment = PublicComment.find(params[:id])
  if value > 0
    @public_comment.add_or_update_evaluation(:pubcom_votes_up, value, @current_user)
  else
    @public_comment.add_or_update_evaluation(:pubcom_votes_down, value, @current_user)
  end

  respond_to do |format|
    format.js # vote.js.erb
  end
end

my buttons vote other comments up....help!

github.com/egong/scribe

Does this gem work in Rails 4? Documentation is unclear. I could greenfield a 3.2 app if need be.

Hey everyone, so I am trying to use this on Rails 4 with Devise, is this not supported?

I get this error:

activemodel-4.0.0/lib/active_model/deprecated_mass_assignment_security.rb:14:in attr_accessible': attr_accessible is extracted out of Rails into a gem. Please use new recommended protection model for params(strong_parameters) or add protected_attributes to your Gemfile to use old one. (RuntimeError)

Should I be using the "Protected Attributes" or having strong parameters defined in a controller somewhere, but which fields?

Thank you.

hey @ryan! I used your home brew in a rails 4 app, but the self.by_votes method doesn't seem to work. As is... it orders things, but it duplicates each item for each time they've been voted on. I was wondering if you had any ideas?

Has anyone tried to implement an Activity tracker (see ep. 407, et.al) with this?

THIS GEM DOES NOT WORK WITH RAILS 4. Don't even try it. The employee who made it formerly worked for Twitter, then left Twitter, and no one else on the team is interested in supporting it. Recommend the Thumbs Up gem. https://github.com/bouchard/thumbs_up

UPDATE: Rails 4 support was just merged into this, so it should work with Rails 4 now.

UPDATE:
for evaluation I used:

has_many :rs_evaluations, class_name: "ReputationSystem::Evaluation", as: :source

so change is just class_name