prevent users with much negative karma from submitting new stories

app/controllers/stories_controller.rb

@@ -3,6 +3,7 @@ class StoriesController < ApplicationController
     :only => [ :upvote, :downvote, :unvote, :hide, :unhide, :preview ]
   before_filter :require_logged_in_user, :only => [ :destroy, :create, :edit,
     :fetch_url_attributes, :new, :suggest ]
+  before_filter :verify_user_can_submit_stories, :only => [ :new, :create ]
   before_filter :find_user_story, :only => [ :destroy, :edit, :undelete,
     :update ]
   before_filter :find_story!, :only => [ :suggest, :submit_suggestions ]
@@ -378,4 +379,11 @@ private
       end
     end
   end
+
+  def verify_user_can_submit_stories
+    if !@user.can_submit_stories?
+      flash[:error] = "You are not allowed to submit new stories."
+      return redirect_to "/"
+    end
+  end
 end

app/models/user.rb

@@ -64,6 +64,9 @@ class User < ActiveRecord::Base
   # minimum karma required to be able to offer title/tag suggestions
   MIN_KARMA_TO_SUGGEST = 10
 
+  # minimum karma required to be able to submit new stories
+  MIN_KARMA_TO_SUBMIT_STORIES = -4
+
   def self.recalculate_all_karmas!
     User.all.each do |u|
       u.karma = u.stories.map(&:score).sum + u.comments.map(&:score).sum
@@ -178,10 +181,18 @@ class User < ActiveRecord::Base
     false
   end
 
+  def can_invite?
+    !disabled_invite_at? && self.can_submit_stories?
+  end
+
   def can_offer_suggestions?
     !self.is_new? && (self.karma >= MIN_KARMA_TO_SUGGEST)
   end
 
+  def can_submit_stories?
+    self.karma >= MIN_KARMA_TO_SUBMIT_STORIES
+  end
+
   def check_session_token
     if self.session_token.blank?
       self.session_token = Utils.random_str(60)
@@ -281,10 +292,6 @@ class User < ActiveRecord::Base
     banned_at?
   end
 
-  def can_invite?
-    !disabled_invite_at?
-  end
-
   def is_new?
     Time.now - self.created_at <= NEW_USER_DAYS.days
   end

app/views/layouts/application.html.erb

@@ -55,7 +55,7 @@
           "/comments" => t('.commentslink')
         } %>
 
-        <% if @user %>
+        <% if @user && @user.can_submit_stories? %>
           <% links.merge!({ "/threads" => t('.yourthreadslink'),
             "/stories/new" => t('.submitstorylink') }) %>
         <% end %>