show how many users are filtering each tag

app/assets/javascripts/select2.js

@@ -493,7 +493,7 @@
                         if (i === 0 && placeholder !== undefined && text === "") return true;
 
                         if (query.matcher(term, text)) {
-                            data.results.push({id: e.attr("value"), text: text});
+                            data.results.push({id: e.attr("value"), text: (e.attr("data-html") == undefined ? text : e.attr("data-html")) });
                         }
                     });
                     query.callback(data);

app/assets/stylesheets/application.css

@@ -1109,3 +1109,10 @@ div.modal_confirm_content div.modal_confirm_buttonbar input.default_button {
 	-o-box-shadow     : none;
 	box-shadow        : none;
 }
+
+.select2-container .select2-results li em {
+	background: none;
+	color: #aaa;
+	font-style: italic;
+	padding-left: 0.5em;
+}

app/models/tag.rb

@@ -1,2 +1,16 @@
 class Tag < ActiveRecord::Base
+  attr_accessor :filtered_count
+
+  def self.all_with_filtered_counts
+    counts = TagFilter.count(:group => "tag_id")
+
+    Tag.order(:tag).all.map{|t|
+      t.filtered_count = counts[t.id].to_i
+      t
+    }
+  end
+
+  def filtered_count
+    @filtered_count ||= TagFilter.where(:tag_id => self.id).count
+  end
 end

app/views/stories/_form.html.erb

@@ -23,9 +23,14 @@
   <div class="boxline" style="margin-bottom: 2px;">
 	<%= f.label :tags_a, "Tags:", :class => "required",
     :style => "line-height: 2.3em;" %>
-  <%= f.select "tags_a", Tag.order(:tag).map{|t|
-    [ "#{t.tag} - #{t.description}", t.tag ] }, {},
-    { :multiple => true } %>
+  <%= f.select "tags_a", options_for_select(
+    Tag.all_with_filtered_counts.map{|t|
+    [ "#{t.tag} - #{t.description}", t.tag, { "data-html" => raw("<strong>") +
+      t.tag + raw("</strong> - ") + t.description.to_s +
+      (t.filtered_count == 0 ? "" :
+      raw(" <em>") + "#{t.filtered_count} user" +
+      (t.filtered_count == 1 ? "" : "s") + " filtering" +
+      raw("</em>")) } ]}), {}, { :multiple => true } %>
   </div>
 
   <div class="boxline">