Question

The basic outline of my code is this:

1. Check to see if a user has a “vote” object associated with a particular “report”

2. If there is no such vote object, then create one.

3. Assign it a value (upvote vs. downvote)

4. If there IS such a vote object, then change the existing vote’s value.

Here’s the problem though…The program never FINDS the vote object even when it (apparently) exists in the database!

My code looks like this:

    def vote_up # voting code
      @was_new = false

      current_report = Report.find(params[:id])
      @report = current_report

      begin
        @vote = current_report.votes.find_by_user_id(current_user.id) #<<---HERE IS THE BUG!!
      rescue
        @was_new = true
        @vote = Vote.create(:user_id => current_user.id, :votable_type => 'Report', :value => 0)   # default vote score of zero
      end

      current_report.votes << @vote
      current_report.save

      if @was_new #if the vote was new...
        @report.upvotes += 1
        @vote.value = 1

      elsif !@was_new and @vote.value == -1 #else, if you are changing your vote...

        @report.upvotes += 1
        @report.downvotes -= 1
        @vote.value = 1

      end

        @vote.save
        @report.save

        redirect_to(report_path(@report))
    end

The error I receive is this:

 SQLite3::SQLException: no such column: votes.votable_id: SELECT  "votes".* FROM "votes"  WHERE "votes"."votable_id" = 3 AND "votes"."votable_type" = 'Report' AND "votes"."user_id" = 1 LIMIT 1

I feel like the solution is simple, like writing @vote = current_report.votes.find(params[:user_id], :as => :user_id) or something like that.

EDIT:

I got it working. Here’s the working code:

 def vote_up # voting code

 @exists = false

 get_vote(1)

 if !@exists #if the vote was new...
  @report.upvotes += 1

elsif @exists and @vote.value == -1 #else, if you are changing your vote...

  @report.upvotes += 1
  @report.downvotes -= 1
  @vote.value = 1

    end

    @vote.save
    @report.save

 redirect_to(report_path(@report))

end

def vote_down

 @exists = false

    get_vote(-1)

    if !@exists # this should handle vote changing
  @report.downvotes += 1

  elsif @exists and @vote.value == 1

  @report.downvotes += 1
  @report.upvotes -= 1
  @vote.value = -1

    end

    @vote.save
    @report.save

redirect_to(report_path(@report))

end

 def get_vote(val) # voting code
 current_report = Report.find(params[:id])

 @report = current_report
 @vote = current_report.votes.find_by_user_id(current_user.id) 

 unless @vote # create a vote only if it's nil
   @vote = Vote.create(:user_id => current_user.id, :votable_id => 3, :votable_type => 'Report',  :value => val) # default vote score of zero
   current_report.votes << @vote
  current_report.save
 else #if it's not nil
  @exists = true
end

end

Answer 1

Check the Dynamic attribute-based finders. You should be able to do something like: (untested code)

def vote_up # voting code
  current_report = Report.find(params[:id])
  @report = current_report

  # gets the vote or initialize a new one for that user_id
  @vote = current_report.votes.find_or_initialize_by_user_id(current_user.id) 

  if !@vote.saved?
    @vote.votable_type = 'Report' 
    @vote.value = 0
    #  current_report.votes << @vote #not sure if it's necessary
    #  current_report.save #not sure if it's necessary

    @report.upvotes += 1
    @vote.value = 1
  elsif @vote.value == -1 
    @report.upvotes += 1
    @report.downvotes -= 1
    @vote.value = 1
  end

  @vote.save
  @report.save  

  redirect_to(report_path(@report))
end

IMPORTANT: And one more thing. You should port most of this method to your Report model, it’s clearly a business thing, so there is where this should go!