List the "Watching First Post" tags on preferences

app/assets/javascripts/discourse/models/user.js.es6

@@ -158,10 +158,10 @@ const User = RestModel.extend({
       'card_background',
       'muted_tags',
       'tracked_tags',
-            'watched_tags'
-          );
+      'watched_tags',
+      'watching_first_post_tags');
 
-    [       'email_always',
+    ['email_always',
      'mailing_list_mode',
      'mailing_list_mode_frequency',
      'external_links_in_new_tab',

app/assets/javascripts/discourse/templates/user/preferences.hbs

@@ -288,6 +288,11 @@
         {{tag-chooser tags=model.tracked_tags blacklist=selectedTags allowCreate=false placeholder="" everyTag="true" unlimitedTagCount="true"}}
       </div>
       <div class="instructions">{{i18n 'user.tracked_tags_instructions'}}</div>
+      <div class="controls tag-controls">
+        <label><span class="icon fa fa-dot-circle-o watching-first-post"></span> {{i18n 'user.watched_first_post_tags'}}</label>
+        {{tag-chooser tags=model.watching_first_post_tags blacklist=selectedTags allowCreate=false placeholder="" everyTag="true" unlimitedTagCount="true"}}
+      </div>
+      <div class="instructions">{{i18n 'user.watched_first_post_tags_instructions'}}</div>
       <div class="controls tag-controls">
         <label><span class="icon fa fa-times-circle muted"></span> {{i18n 'user.muted_tags'}}</label>
         {{tag-chooser tags=model.muted_tags blacklist=selectedTags allowCreate=false placeholder="" everyTag="true" unlimitedTagCount="true"}}

app/serializers/user_serializer.rb

@@ -84,6 +84,7 @@ class UserSerializer < BasicUserSerializer
   private_attributes :locale,
                      :muted_category_ids,
                      :watched_tags,
+                     :watching_first_post_tags,
                      :tracked_tags,
                      :muted_tags,
                      :tracked_category_ids,
@@ -258,6 +259,10 @@ class UserSerializer < BasicUserSerializer
     TagUser.lookup(object, :tracking).joins(:tag).pluck('tags.name')
   end
 
+  def watching_first_post_tags
+    TagUser.lookup(object, :watching_first_post).joins(:tag).pluck('tags.name')
+  end
+
   def watched_tags
     TagUser.lookup(object, :watching).joins(:tag).pluck('tags.name')
   end

app/services/user_updater.rb

@@ -8,6 +8,7 @@ class UserUpdater
   }
 
   TAG_NAMES = {
+    watching_first_post_tags: :watching_first_post,
     watched_tags: :watching,
     tracked_tags: :tracking,
     muted_tags: :muted

config/locales/client.en.yml

@@ -553,6 +553,9 @@ en:
       tracked_categories_instructions: "You will automatically track all topics in these categories. A count of new posts will appear next to the topic."
       watched_first_post_categories: "Watching First Post"
       watched_first_post_categories_instructions: "You will be notified of the first post in each new topic in these categories."
+      watched_first_post_tags: "Watching First Post"
+      watched_first_post_tags_instructions: "You will be notified of the first post in each new topic with these tags."
+
       muted_categories: "Muted"
       muted_categories_instructions: "You will not be notified of anything about new topics in these categories, and they will not appear in latest."
       delete_account: "Delete My Account"