Staff action logs can be filtered to changes of one site setting

app/assets/javascripts/admin/controllers/admin_logs_staff_action_logs_controller.js

@@ -18,7 +18,7 @@ Discourse.AdminLogsStaffActionLogsController = Ember.ArrayController.extend(Disc
       self.set('content', result);
       self.set('loading', false);
     });
-  }.observes('filters.action_name', 'filters.staff_user', 'filters.target_user'),
+  }.observes('filters.action_name', 'filters.staff_user', 'filters.target_user', 'filters.subject'),
 
   toggleFullDetails: function(target) {
     target.set('showFullDetails', !target.get('showFullDetails'));
@@ -26,7 +26,7 @@ Discourse.AdminLogsStaffActionLogsController = Ember.ArrayController.extend(Disc
 
   filtersExists: function() {
     return (_.size(this.get('filters')) > 0);
-  }.property('filters.action_name', 'filters.staff_user', 'filters.target_user'),
+  }.property('filters.action_name', 'filters.staff_user', 'filters.target_user', 'filters.subject'),
 
   clearFilter: function(key) {
     delete this.get('filters')[key];
@@ -55,5 +55,9 @@ Discourse.AdminLogsStaffActionLogsController = Ember.ArrayController.extend(Disc
 
   filterByTargetUser: function(target_user) {
     this.set('filters.target_user', target_user.username);
+  },
+
+  filterBySubject: function(subject) {
+    this.set('filters.subject', subject);
   }
 });

app/assets/javascripts/admin/templates/logs/staff_action_logs.js.handlebars

@@ -20,6 +20,12 @@
       <i class="icon icon-remove-sign"></i>
     </a>
   {{/if}}
+  {{#if filters.subject}}
+    <a {{action clearFilter "subject"}} class="filter">
+      <span class="label">{{i18n admin.logs.staff_actions.subject}}</span>: {{filters.subject}}
+      <i class="icon icon-remove-sign"></i>
+    </a>
+  {{/if}}
 </div>
 
 <div class='table staff-actions'>

app/assets/javascripts/admin/templates/logs/staff_action_logs_list_item.js.handlebars

@@ -11,7 +11,7 @@
     <a {{action filterByTargetUser target_user}}>{{target_user.username}}</a>
   {{/if}}
   {{#if subject}}
-    <span {{bindAttr title="subject"}}>{{subject}}</span>
+    <a {{action filterBySubject subject}} {{bindAttr title="subject"}}>{{subject}}</a>
   {{/if}}
 </div>
 <div class="col value created_at">{{unboundAgeWithTooltip created_at}}</div>

app/controllers/admin/staff_action_logs_controller.rb

@@ -1,7 +1,7 @@
 class Admin::StaffActionLogsController < Admin::AdminController
 
   def index
-    staff_action_logs = StaffActionLog.with_filters(params.slice(:action_name, :staff_user, :target_user)).limit(200).order('id DESC').includes(:staff_user, :target_user).to_a
+    staff_action_logs = StaffActionLog.with_filters(params.slice(:action_name, :staff_user, :target_user, :subject)).limit(200).order('id DESC').includes(:staff_user, :target_user).to_a
     render_serialized(staff_action_logs, StaffActionLogSerializer)
   end
 

app/models/staff_action_log.rb

@@ -22,6 +22,7 @@ class StaffActionLog < ActiveRecord::Base
         query = query.where("#{key.to_s}_id = ?", obj_id)
       end
     end
+    query = query.where("subject = ?", filters[:subject]) if filters[:subject]
     query
   end
 end

db/migrate/20130820174431_add_subject_index_to_staff_action_logs.rb

@@ -0,0 +1,5 @@
+class AddSubjectIndexToStaffActionLogs < ActiveRecord::Migration
+  def change
+    add_index :staff_action_logs, [:subject, :id]
+  end
+end