FEATURE: Allow staffs to tag PMs

lib/discourse_tagging.rb

@@ -4,10 +4,10 @@ module DiscourseTagging
   TAGS_FILTER_REGEXP = /[\/\?#\[\]@!\$&'\(\)\*\+,;=\.%\\`^\s|\{\}"<>]+/ # /?#[]@!$&'()*+,;=.%\`^|{}"<>
 
   def self.tag_topic_by_names(topic, guardian, tag_names_arg, append: false)
-    if SiteSetting.tagging_enabled
+    if can_tag?(topic)
       tag_names = DiscourseTagging.tags_for_saving(tag_names_arg, guardian) || []
 
-      old_tag_names = topic.tags.map(&:name) || []
+      old_tag_names = topic.tags.pluck(:name) || []
       new_tag_names = tag_names - old_tag_names
       removed_tag_names = old_tag_names - tag_names
 

lib/guardian.rb

@@ -129,6 +129,12 @@ class Guardian
   alias :can_see_flags? :can_moderate?
   alias :can_close? :can_moderate?
 
+  def can_tag?(obj)
+    return false unless obj && obj.is_a?(Topic)
+
+    obj.private_message? ? can_tag_pms? : can_tag_topics?
+  end
+
   def can_send_activation_email?(user)
     user && is_staff? && !SiteSetting.must_approve_users?
   end

lib/guardian/tag_guardian.rb

@@ -5,7 +5,11 @@ module TagGuardian
   end
 
   def can_tag_topics?
-    user && user.has_trust_level?(SiteSetting.min_trust_level_to_tag_topics.to_i)
+    user && SiteSetting.tagging_enabled && user.has_trust_level?(SiteSetting.min_trust_level_to_tag_topics.to_i)
+  end
+
+  def can_tag_pms?
+    is_staff? && SiteSetting.tagging_enabled && SiteSetting.allow_staff_to_tag_in_pm
   end
 
   def can_admin_tags?

lib/topic_query.rb

@@ -269,6 +269,14 @@ class TopicQuery
     create_list(:private_messages, {}, list)
   end
 
+  def list_private_messages_tag(user)
+    list = private_messages_for(user, :all)
+    tag_id = Tag.where('name ilike ?', @options[:tags][0]).pluck(:id).first
+    list = list.joins("JOIN topic_tags tt ON tt.topic_id = topics.id AND
+                      tt.tag_id = #{tag_id}")
+    create_list(:private_messages, {}, list)
+  end
+
   def list_category_topic_ids(category)
     query = default_results(category: category.id)
     pinned_ids = query.where('pinned_at IS NOT NULL AND category_id = ?', category.id).limit(nil).order('pinned_at DESC').pluck(:id)