new 'addNavigationBarItem' plugin api

app/assets/javascripts/discourse/lib/plugin-api.js.es6

@@ -20,10 +20,11 @@ import { addPostClassesCallback } from 'discourse/widgets/post';
 import { addPostTransformCallback } from 'discourse/widgets/post-stream';
 import { attachAdditionalPanel } from 'discourse/widgets/header';
 import { registerIconRenderer } from 'discourse-common/lib/icon-library';
+import { addNavItem } from 'discourse/models/nav-item';
 
 
 // If you add any methods to the API ensure you bump up this number
-const PLUGIN_API_VERSION = '0.8.8';
+const PLUGIN_API_VERSION = '0.8.9';
 
 class PluginApi {
   constructor(version, container) {
@@ -524,6 +525,22 @@ class PluginApi {
   addPostTransformCallback(callback) {
     addPostTransformCallback(callback);
   }
+
+  /**
+  *
+  * Adds a new item in the navigation bar.
+  *
+  * Example:
+  *
+  * addNavigationBarItem({
+  *   name: "discourse",
+  *   displayName: "Discourse"
+  *   href: "https://www.discourse.org",
+  * })
+  */
+  addNavigationBarItem(item) {
+    addNavItem(item);
+  }
 }
 
 let _pluginv01;

app/assets/javascripts/discourse/models/nav-item.js.es6

@@ -1,83 +1,92 @@
 import { toTitleCase } from 'discourse/lib/formatter';
+import computed from 'ember-addons/ember-computed-decorators';
 
 const NavItem = Discourse.Model.extend({
 
-  displayName: function() {
-    var categoryName = this.get('categoryName'),
-        name = this.get('name'),
-        count = this.get('count') || 0;
+  @computed("categoryName", "name", "count")
+  displayName(categoryName, name, count) {
+    count = count || 0;
 
     if (name === 'latest' && !Discourse.Site.currentProp('mobileView')) {
       count = 0;
     }
 
-    var extra = { count: count };
-    var titleKey = count === 0 ? '.title' : '.title_with_count';
+    let extra = { count: count };
+    const titleKey = count === 0 ? '.title' : '.title_with_count';
 
     if (categoryName) {
       name = 'category';
       extra.categoryName = toTitleCase(categoryName);
     }
-    return I18n.t("filters." + name.replace("/", ".") + titleKey, extra);
-  }.property('categoryName', 'name', 'count'),
 
-  categoryName: function() {
-    var split = this.get('name').split('/');
+    return I18n.t(`filters.${name.replace("/", ".") + titleKey}`, extra);
+  },
+
+  @computed("name")
+  categoryName(name) {
+    const split = name.split('/');
     return split[0] === 'category' ? split[1] : null;
-  }.property('name'),
+  },
 
-  categorySlug: function() {
-    var split = this.get('name').split('/');
+  @computed("name")
+  categorySlug(name) {
+    const split = name.split('/');
     if (split[0] === 'category' && split[1]) {
-      var cat = Discourse.Site.current().categories.findBy('nameLower', split[1].toLowerCase());
+      const cat = Discourse.Site.current().categories.findBy('nameLower', split[1].toLowerCase());
       return cat ? Discourse.Category.slugFor(cat) : null;
     }
     return null;
-  }.property('name'),
+  },
+
+  @computed("filterMode")
+  href(filterMode) {
+    let customHref = null;
 
-  href: function() {
-    var customHref = null;
     _.each(NavItem.customNavItemHrefs, function(cb) {
       customHref = cb.call(this, this);
       if (customHref) { return false; }
     }, this);
+
     if (customHref) { return customHref; }
-    return Discourse.getURL("/") + this.get('filterMode');
-  }.property('filterMode'),
 
-  // href from this item
-  filterMode: function() {
-    var name = this.get('name');
+    return Discourse.getURL("/") + filterMode;
+  },
 
-    if( name.split('/')[0] === 'category' ) {
-      return 'c/' + this.get('categorySlug');
+  @computed("name", "category", "categorySlug", "noSubcategories")
+  filterMode(name, category, categorySlug, noSubcategories) {
+    if (name.split('/')[0] === 'category') {
+      return 'c/' + categorySlug;
     } else {
-      var mode = "",
-      category = this.get("category");
-
-      if(category){
+      let mode = "";
+      if (category) {
         mode += "c/";
-        mode += Discourse.Category.slugFor(this.get('category'));
-        if (this.get('noSubcategories')) { mode += '/none'; }
+        mode += Discourse.Category.slugFor(category);
+        if (noSubcategories) { mode += '/none'; }
         mode += "/l/";
       }
       return mode + name.replace(' ', '-');
     }
-  }.property('name'),
+  },
 
-  count: function() {
-    var state = this.get('topicTrackingState');
+  @computed("topicTrackingState", "name", "category")
+  count(state, name, category) {
     if (state) {
-      return state.lookupCount(this.get('name'), this.get('category'));
+      return state.lookupCount(name, category);
     }
-  }.property('topicTrackingState.messageCount')
+  }
 
 });
 
+ const ExtraNavItem = NavItem.extend({
+  @computed("href")
+  href: (href) => href
+});
+
 NavItem.reopenClass({
 
   extraArgsCallbacks: [],
   customNavItemHrefs: [],
+  extraNavItems: [],
 
   // create a nav item from the text, will return null if there is not valid nav item for this particular text
   fromText(text, opts) {
@@ -113,16 +122,24 @@ NavItem.reopenClass({
       items.push(args.filterMode);
     }
 
-    return items.map(i => Discourse.NavItem.fromText(i, args))
-                .filter(i => i !== null && !(category && i.get("name").indexOf("categor") === 0));
+    items = items.map(i => Discourse.NavItem.fromText(i, args))
+                 .filter(i => i !== null && !(category && i.get("name").indexOf("categor") === 0));
+
+    return items.concat(NavItem.extraNavItems);
   }
 
 });
 
 export default NavItem;
+
 export function extraNavItemProperties(cb) {
   NavItem.extraArgsCallbacks.push(cb);
 }
+
 export function customNavItemHref(cb) {
   NavItem.customNavItemHrefs.push(cb);
 }
+
+export function addNavItem(item) {
+  NavItem.extraNavItems.push(ExtraNavItem.create(item));
+}