FEATURE: add setting to display tags by tag groups

app/assets/javascripts/discourse/controllers/tags-index.js.es6

@@ -1,7 +1,20 @@
+import computed from 'ember-addons/ember-computed-decorators';
+
 export default Ember.Controller.extend({
   sortProperties: ['count:desc', 'id'],
 
   canAdminTags: Ember.computed.alias("currentUser.staff"),
+  groupedByCategory: Ember.computed.notEmpty('model.extras.categories'),
+  groupedByTagGroup: Ember.computed.notEmpty('model.extras.tag_groups'),
+
+  @computed('groupedByCategory', 'groupedByTagGroup')
+  otherTagsTitleKey(groupedByCategory, groupedByTagGroup) {
+    if (!groupedByCategory && !groupedByTagGroup) {
+      return 'tagging.all_tags';
+    } else {
+      return 'tagging.other_tags';
+    }
+  },
 
   actions: {
     sortByCount() {

app/assets/javascripts/discourse/templates/components/tag-list.hbs

@@ -4,6 +4,9 @@
 {{#if category}}
   {{category-title-link category=category}}
 {{/if}}
+{{#if tagGroupName}}
+  <h3>{{tagGroupName}}</h3>
+{{/if}}
 {{#each sortedTags as |tag|}}
   <div class='tag-box'>
     {{#if tag.count}}

app/assets/javascripts/discourse/templates/tags/index.hbs

@@ -23,4 +23,8 @@
   {{tag-list tags=category.tags sortProperties=sortProperties categoryId=category.id}}
 {{/each}}
 
-{{tag-list tags=model sortProperties=sortProperties titleKey="tagging.all_tags"}}
+{{#each model.extras.tag_groups as |tagGroup|}}
+  {{tag-list tags=tagGroup.tags sortProperties=sortProperties tagGroupName=tagGroup.name}}
+{{/each}}
+
+{{tag-list tags=model sortProperties=sortProperties titleKey=otherTagsTitleKey}}

app/controllers/tags_controller.rb

@@ -19,30 +19,60 @@ class TagsController < ::ApplicationController
   before_action :set_category_from_params, except: [:index, :update, :destroy, :tag_feed, :search, :notifications, :update_notifications]
 
   def index
-    categories = Category.where("id in (select category_id from category_tags)")
-      .where("id in (?)", guardian.allowed_category_ids)
-      .preload(:tags)
-    category_tag_counts = categories.map do |c|
-      h = Tag.category_tags_by_count_query(c, limit: 300).count(Tag::COUNT_ARG)
-      h.merge!(c.tags.where.not(name: h.keys).inject({}) { |sum, t| sum[t.name] = 0; sum }) # unused tags
-      { id: c.id, tags: self.class.tag_counts_json(h) }
-    end
-
-    tag_counts = self.class.tags_by_count(guardian, limit: 300).count(Tag::COUNT_ARG)
-    @tags = self.class.tag_counts_json(tag_counts)
-
     @description_meta = I18n.t("tags.title")
     @title = @description_meta
 
     respond_to do |format|
+
       format.html do
+        tag_counts = self.class.tags_by_count(guardian, limit: 300).count(Tag::COUNT_ARG)
+        @tags = self.class.tag_counts_json(tag_counts)
         render :index
       end
+
       format.json do
-        render json: {
-          tags: @tags,
-          extras: { categories: category_tag_counts }
-        }
+        if SiteSetting.tags_listed_by_group
+          # TODO: performance is bad
+          grouped_tag_counts = TagGroup.order('name ASC').preload(:tags).map do |tag_group|
+            h = Tag.tags_by_count_query(limit: 300)
+              .joins("LEFT JOIN tag_group_memberships ON tags.id = tag_group_memberships.tag_id")
+              .where('tag_group_memberships.tag_group_id = ?', tag_group.id)
+              .count(Tag::COUNT_ARG)
+            { id: tag_group.id, name: tag_group.name, tags: self.class.tag_counts_json(h) }
+          end
+
+          ungrouped_tag_counts = guardian.filter_allowed_categories(
+            Tag.tags_by_count_query(limit: 300)
+              .where("tags.id NOT IN (select tag_id from tag_group_memberships)")
+              .count(Tag::COUNT_ARG)
+          )
+
+          render json: {
+            tags: self.class.tag_counts_json(ungrouped_tag_counts), # tags that don't belong to a group
+            extras: { tag_groups: grouped_tag_counts }
+          }
+        else
+          unrestricted_tag_counts = guardian.filter_allowed_categories(
+            Tag.tags_by_count_query(limit: 300)
+              .where("tags.id NOT IN (select tag_id from category_tags)")
+              .count(Tag::COUNT_ARG)
+          )
+
+          categories = Category.where("id in (select category_id from category_tags)")
+            .where("id in (?)", guardian.allowed_category_ids)
+            .preload(:tags)
+
+          category_tag_counts = categories.map do |c|
+            h = Tag.category_tags_by_count_query(c, limit: 300).count(Tag::COUNT_ARG)
+            h.merge!(c.tags.where.not(name: h.keys).inject({}) { |sum, t| sum[t.name] = 0; sum }) # unused tags
+            { id: c.id, tags: self.class.tag_counts_json(h) }
+          end
+
+          render json: {
+            tags: self.class.tag_counts_json(unrestricted_tag_counts),
+            extras: { categories: category_tag_counts }
+          }
+        end
       end
     end
   end

config/locales/client.en.yml

@@ -2507,6 +2507,7 @@ en:
 
     tagging:
       all_tags: "All Tags"
+      other_tags: "Other Tags"
       selector_all_tags: "all tags"
       selector_no_tags: "no tags"
       changed: "tags changed:"

config/locales/server.en.yml

@@ -1584,6 +1584,7 @@ en:
     show_filter_by_tag: "Show a dropdown to filter a topic list by tag."
     max_tags_in_filter_list: "Maximum number of tags to show in the filter dropdown. The most used tags will be shown."
     tags_sort_alphabetically: "Show tags in alphabetical order. Default is to show in order of popularity."
+    tags_listed_by_group: "List tags by tag group on the Tags page (/tags)."
     tag_style: "Visual style for tag badges."
     staff_tags: "A list of tags that can only be applied by staff members"
     min_trust_level_to_tag_topics: "Minimum trust level required to tag topics"

config/site_settings.yml

@@ -1521,6 +1521,9 @@ tags:
     client: true
     default: false
     refresh: true
+  tags_listed_by_group:
+    client: true
+    default: false
   staff_tags:
     type: list
     client: true