meta.rb

# from app/models/submission.rb

# Current version, does not work.

  [:submission_comments, :visible_submission_comments].each do |method|
    alias_method "old_#{method}", method
    instance_eval <<-CODE
      def #{method}(options = {})
        res = old_#{method}(options)
        res = res.select{|sc| sc.grants_right?(@comment_limiting_user, @comment_limiting_session, :read) } if @comment_limiting_user
        res
      end
    CODE
  end

# >> @sub = SubmissionComment.last.submission.tap{|s| s.limit_comments(User.find(2))}; nil
# >> @sub.visible_submission_comments.count
# => 7

# --------------------------------------------------------------------------------------------

# Works correctly

  alias_method :old_submission_comments, :submission_comments
  def submission_comments(options = {})
    res = old_submission_comments(options)
    res = res.select{|sc| sc.grants_right?(@comment_limiting_user, @comment_limiting_session, :read) } if @comment_limiting_user
    res
  end

  alias_method :old_visible_submission_comments, :visible_submission_comments
  def visible_submission_comments(options = {})
    res = old_visible_submission_comments(options)
    res = res.select{|sc| sc.grants_right?(@comment_limiting_user, @comment_limiting_session, :read) } if @comment_limiting_user
    res
  end

# >> @sub = SubmissionComment.last.submission.tap{|s| s.limit_comments(User.find(2))}; nil
# >> @sub.visible_submission_comments.count
# => 5