FEATURE: Support filtering of groups page by category if in url

app/assets/javascripts/discourse/components/group-activity-filter.js.es6

@@ -0,0 +1,3 @@
+export default Ember.Component.extend({
+  tagName: 'li'
+});

app/assets/javascripts/discourse/controllers/group-activity-posts.js.es6

@@ -2,6 +2,7 @@ import { fmt } from 'discourse/lib/computed';
 
 export default Ember.Controller.extend({
   group: Ember.inject.controller(),
+  groupActivity: Ember.inject.controller(),
   loading: false,
   emptyText: fmt('type', 'groups.empty.%@'),
 
@@ -14,7 +15,9 @@ export default Ember.Controller.extend({
         const beforePostId = posts[posts.length-1].get('id');
         const group = this.get('group.model');
 
-        const opts = { beforePostId, type: this.get('type') };
+        let categoryId = this.get('groupActivity.category_id');
+        const opts = { beforePostId, type: this.get('type'), categoryId };
+
         group.findPosts(opts).then(newPosts => {
           posts.addObjects(newPosts);
           this.set('loading', false);

app/assets/javascripts/discourse/controllers/group-activity.js.es6

@@ -2,6 +2,7 @@ import computed from 'ember-addons/ember-computed-decorators';
 
 export default Ember.Controller.extend({
   application: Ember.inject.controller(),
+  queryParams: ['category_id'],
 
   @computed('model.is_group_user')
   showGroupMessages(isGroupUser) {

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

@@ -203,12 +203,13 @@ const Group = RestModel.extend({
   findPosts(opts) {
     opts = opts || {};
 
-    const type = opts['type'] || 'posts';
+    const type = opts.type || 'posts';
 
     var data = {};
     if (opts.beforePostId) { data.before_post_id = opts.beforePostId; }
+    if (opts.categoryId) { data.category_id = parseInt(opts.categoryId); }
 
-    return ajax(`/groups/${this.get('name')}/${type}.json`, { data: data }).then(posts => {
+    return ajax(`/groups/${this.get('name')}/${type}.json`, { data }).then(posts => {
       return posts.map(p => {
         p.user = User.create(p.user);
         p.topic = Topic.create(p.topic);

app/assets/javascripts/discourse/routes/group-activity-posts.js.es6

@@ -6,8 +6,9 @@ export function buildGroupPage(type) {
       return I18n.t(`groups.${type}`);
     },
 
-    model() {
-      return this.modelFor("group").findPosts({ type });
+    model(params, transition) {
+      let categoryId = Ember.get(transition, 'queryParams.category_id');
+      return this.modelFor("group").findPosts({ type, categoryId });
     },
 
     setupController(controller, model) {

app/assets/javascripts/discourse/templates/components/group-activity-filter.hbs

@@ -0,0 +1,3 @@
+{{#link-to (concat 'group.activity.' filter) (query-params category_id=categoryId)}}
+  {{i18n (concat 'groups.' filter)}}
+{{/link-to}}

app/assets/javascripts/discourse/templates/group/activity.hbs

@@ -1,21 +1,10 @@
 <div class='group-activity container'>
   {{#mobile-nav class='group-activity-nav' desktopClass="pull-left nav nav-stacked" currentPath=application.currentPath}}
-    <li>
-      {{#link-to 'group.activity.posts'}}{{i18n 'groups.posts'}}{{/link-to}}
-    </li>
-
-    <li>
-      {{#link-to 'group.activity.topics'}}{{i18n 'groups.topics'}}{{/link-to}}
-    </li>
-
-    <li>
-      {{#link-to 'group.activity.mentions'}}{{i18n 'groups.mentions'}}{{/link-to}}
-    </li>
-
+    {{group-activity-filter filter="posts" categoryId=category_id}}
+    {{group-activity-filter filter="topics" categoryId=category_id}}
+    {{group-activity-filter filter="mentions" categoryId=category_id}}
     {{#if showGroupMessages}}
-      <li>
-        {{#link-to 'group.activity.messages'}}{{i18n 'groups.messages'}}{{/link-to}}
-      </li>
+      {{group-activity-filter filter="messages"}}
     {{/if}}
   {{/mobile-nav}}