FEATURE: wiki editors are allowed edit tags for wiki topics.

If a wiki editor's TL is greater than 'min trust level to tag topics' site setting then they can edit the tags for any wiki topic.

app/assets/javascripts/discourse/components/composer-title.js.es6

@@ -10,6 +10,7 @@ import afterTransition from "discourse/lib/after-transition";
 export default Ember.Component.extend({
   classNames: ["title-input"],
   watchForLink: Ember.computed.alias("composer.canEditTopicFeaturedLink"),
+  disabled: Ember.computed.or("composer.loading", "composer.disableTitleInput"),
 
   didInsertElement() {
     this._super(...arguments);

app/assets/javascripts/discourse/controllers/composer.js.es6

@@ -186,6 +186,9 @@ export default Ember.Controller.extend({
     );
   },
 
+  disableCategoryChooser: Ember.computed.not("model.topic.details.can_edit"),
+  disableTagsChooser: Ember.computed.not("model.topic.canEditTags"),
+
   isStaffUser: Ember.computed.reads("currentUser.staff"),
 
   canUnlistTopic: Ember.computed.and("model.creatingTopic", "isStaffUser"),

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

@@ -141,6 +141,7 @@ const Composer = RestModel.extend({
   creatingPrivateMessage: Ember.computed.equal("action", PRIVATE_MESSAGE),
   notCreatingPrivateMessage: Ember.computed.not("creatingPrivateMessage"),
   notPrivateMessage: Ember.computed.not("privateMessage"),
+  disableTitleInput: Ember.computed.not("topic.details.can_edit"),
 
   @computed("privateMessage", "archetype.hasOptions")
   showCategoryChooser(isPrivateMessage, hasOptions) {
@@ -784,31 +785,31 @@ const Composer = RestModel.extend({
     let promise = Ember.RSVP.resolve();
 
     // Update the topic if we're editing the first post
-    if (
-      this.title &&
-      post.post_number === 1 &&
-      this.get("topic.details.can_edit")
-    ) {
-      const topicProps = this.getProperties(
-        Object.keys(_edit_topic_serializer)
-      );
-      // frontend should have featuredLink but backend needs featured_link
-      if (topicProps.featuredLink) {
-        topicProps.featured_link = topicProps.featuredLink;
-        delete topicProps.featuredLink;
-      }
-
+    if (this.title && post.post_number === 1) {
       const topic = this.topic;
 
-      // If we're editing a shared draft, keep the original category
-      if (this.action === EDIT_SHARED_DRAFT) {
-        const destinationCategoryId = topicProps.categoryId;
-        promise = promise.then(() =>
-          topic.updateDestinationCategory(destinationCategoryId)
+      if (topic.details.can_edit) {
+        const topicProps = this.getProperties(
+          Object.keys(_edit_topic_serializer)
         );
-        topicProps.categoryId = topic.get("category.id");
+        // frontend should have featuredLink but backend needs featured_link
+        if (topicProps.featuredLink) {
+          topicProps.featured_link = topicProps.featuredLink;
+          delete topicProps.featuredLink;
+        }
+
+        // If we're editing a shared draft, keep the original category
+        if (this.action === EDIT_SHARED_DRAFT) {
+          const destinationCategoryId = topicProps.categoryId;
+          promise = promise.then(() =>
+            topic.updateDestinationCategory(destinationCategoryId)
+          );
+          topicProps.categoryId = topic.get("category.id");
+        }
+        promise = promise.then(() => Topic.update(topic, topicProps));
+      } else if (topic.details.can_edit_tags) {
+        promise = promise.then(() => topic.updateTags(this.tags));
       }
-      promise = promise.then(() => Topic.update(topic, topicProps));
     }
 
     const props = {

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

@@ -546,6 +546,7 @@ const Topic = RestModel.extend({
 
   readLastPost: propertyEqual("last_read_post_number", "highest_post_number"),
   canClearPin: Ember.computed.and("pinned", "readLastPost"),
+  canEditTags: Ember.computed.or("details.can_edit", "details.can_edit_tags"),
 
   archiveMessage() {
     this.set("archiving", true);
@@ -610,6 +611,17 @@ const Topic = RestModel.extend({
     return ajax(`/t/${this.id}/reset-bump-date`, { type: "PUT" }).catch(
       popupAjaxError
     );
+  },
+
+  updateTags(tags) {
+    if (!tags || tags.length === 0) {
+      tags = [""];
+    }
+
+    return ajax(`/t/${this.id}/tags`, {
+      type: "PUT",
+      data: { tags: tags }
+    });
   }
 });
 

app/assets/javascripts/discourse/templates/components/composer-title.hbs

@@ -3,7 +3,7 @@
              id="reply-title"
              maxLength=titleMaxLength
              placeholderKey=composer.titlePlaceholder
-             disabled=composer.loading
+             disabled=disabled
              autocomplete="discourse"}}
 
 {{popup-input-tip validation=validation}}

app/assets/javascripts/discourse/templates/composer.hbs

@@ -76,12 +76,13 @@
                         fullWidthOnMobile=true
                         value=model.categoryId
                         scopedCategoryId=scopedCategoryId
+                        isDisabled=disableCategoryChooser
                         tabindex="3"}}
                       {{popup-input-tip validation=categoryValidation}}
                     </div>
                   {{/if}}
                   {{#if canEditTags}}
-                    {{mini-tag-chooser tags=model.tags tabindex="4" categoryId=model.categoryId minimum=model.minimumRequiredTags}}
+                    {{mini-tag-chooser tags=model.tags tabindex="4" categoryId=model.categoryId minimum=model.minimumRequiredTags isDisabled=disableTagsChooser}}
                     {{popup-input-tip validation=tagValidation}}
                   {{/if}}
                 </div>

app/controllers/topics_controller.rb

@@ -374,6 +374,16 @@ class TopicsController < ApplicationController
     success ? render_serialized(topic, BasicTopicSerializer) : render_json_error(topic)
   end
 
+  def update_tags
+    params.require(:tags)
+    topic = Topic.find_by(id: params[:topic_id])
+    guardian.ensure_can_edit_tags!(topic)
+
+    success = PostRevisor.new(topic.first_post, topic).revise!(current_user, { tags: params[:tags] }, validate_post: false)
+
+    success ? render_serialized(topic, BasicTopicSerializer) : render_json_error(topic)
+  end
+
   def feature_stats
     params.require(:category_id)
     category_id = params[:category_id].to_i

app/serializers/topic_view_details_serializer.rb

@@ -14,7 +14,8 @@ class TopicViewDetailsSerializer < ApplicationSerializer
      :can_reply_as_new_topic,
      :can_flag_topic,
      :can_convert_topic,
-     :can_review_topic]
+     :can_review_topic,
+     :can_edit_tags]
   end
 
   attributes(
@@ -128,6 +129,10 @@ class TopicViewDetailsSerializer < ApplicationSerializer
     scope.can_convert_topic?(object.topic)
   end
 
+  def include_can_edit_tags?
+    !scope.can_edit?(object.topic) && scope.can_edit_tags?(object.topic)
+  end
+
   def allowed_users
     object.topic.allowed_users.reject { |user| object.group_allowed_user_ids.include?(user.id) }
   end

config/routes.rb

@@ -754,6 +754,7 @@ Discourse::Application.routes.draw do
   delete "t/:topic_id/timings" => "topics#destroy_timings", constraints: { topic_id: /\d+/ }
   put "t/:topic_id/bookmark" => "topics#bookmark", constraints: { topic_id: /\d+/ }
   put "t/:topic_id/remove_bookmarks" => "topics#remove_bookmarks", constraints: { topic_id: /\d+/ }
+  put "t/:topic_id/tags" => "topics#update_tags", constraints: { topic_id: /\d+/ }
 
   post "t/:topic_id/notifications" => "topics#set_notifications" , constraints: { topic_id: /\d+/ }
 

lib/guardian/topic_guardian.rb

@@ -184,4 +184,16 @@ module TopicGuardian
   def can_banner_topic?(topic)
     topic && authenticated? && !topic.private_message? && is_staff?
   end
+
+  def can_edit_tags?(topic)
+    return false unless can_tag_topics?
+    return false if topic.private_message? && !can_tag_pms?
+    return true if can_edit_topic?(topic)
+
+    if topic&.first_post&.wiki && (@user.trust_level >= SiteSetting.min_trust_to_edit_wiki_post.to_i)
+      return can_create_post?(topic)
+    end
+
+    false
+  end
 end

spec/requests/topics_controller_spec.rb

@@ -1027,6 +1027,31 @@ RSpec.describe TopicsController do
             expect(topic.tags.pluck(:id)).to contain_exactly(tag.id)
           end
 
+          it "can add a tag to wiki topic" do
+            SiteSetting.min_trust_to_edit_wiki_post = 2
+            topic.first_post.update!(wiki: true)
+            user = Fabricate(:user)
+            sign_in(user)
+
+            expect do
+              put "/t/#{topic.id}/tags.json", params: {
+                tags: [tag.name]
+              }
+            end.not_to change { topic.reload.first_post.revisions.count }
+
+            expect(response.status).to eq(403)
+            user.update!(trust_level: 2)
+
+            expect do
+              put "/t/#{topic.id}/tags.json", params: {
+                tags: [tag.name]
+              }
+            end.to change { topic.reload.first_post.revisions.count }.by(1)
+
+            expect(response.status).to eq(200)
+            expect(topic.tags.pluck(:id)).to contain_exactly(tag.id)
+          end
+
           it 'does not remove tag if no params is given' do
             topic.tags << tag
 

spec/serializers/topic_view_serializer_spec.rb

@@ -257,6 +257,26 @@ describe TopicViewSerializer do
       expect(details[:allowed_users].find { |au| au[:id] == pm.user_id }).to be_present
       expect(details[:allowed_groups].find { |ag| ag[:id] == group.id }).to be_present
     end
+
+    context "can_edit_tags" do
+      before do
+        SiteSetting.tagging_enabled = true
+        SiteSetting.min_trust_to_edit_wiki_post = 2
+      end
+
+      it "returns true when user can edit a wiki topic" do
+        post = Fabricate(:post, wiki: true)
+        topic = Fabricate(:topic, first_post: post)
+
+        json = serialize_topic(topic, user)
+        expect(json[:details][:can_edit_tags]).to be_nil
+
+        user.update!(trust_level: 2)
+
+        json = serialize_topic(topic, user)
+        expect(json[:details][:can_edit_tags]).to eq(true)
+      end
+    end
   end
 
 end