Added reset-to-homepage behaviour when clicking "view site" link

no issue
- return a basic "guid" from the site's `model` hook so that we have some data which changes on each refresh
- add an action to the wrapper element of the "view site" link which will cause the route to refresh when clicked if we're already on the route
- move the site iframe into a component so that it can watch an @uuid property and force a reset of the iframe's `src` when it detects a change

ghost/admin/app/components/gh-nav-menu.js

@@ -1,6 +1,7 @@
 import Component from '@ember/component';
 import calculatePosition from 'ember-basic-dropdown/utils/calculate-position';
 import {computed} from '@ember/object';
+import {getOwner} from '@ember/application';
 import {htmlSafe} from '@ember/string';
 import {inject as service} from '@ember/service';
 
@@ -8,7 +9,7 @@ export default Component.extend({
     config: service(),
     feature: service(),
     ghostPaths: service(),
-    router: service('router'),
+    router: service(),
     session: service(),
     ui: service(),
 
@@ -42,6 +43,17 @@ export default Component.extend({
         this._setIconStyle();
     },
 
+    actions: {
+        transitionToOrRefreshSite() {
+            let {currentRouteName} = this.router;
+            if (currentRouteName === 'site') {
+                getOwner(this).lookup(`route:${currentRouteName}`).refresh();
+            } else {
+                this.router.transitionTo('site');
+            }
+        }
+    },
+
     // equivalent to "left: auto; right: -20px"
     userDropdownPosition(trigger, dropdown) {
         let {horizontalPosition, verticalPosition, style} = calculatePosition(...arguments);

ghost/admin/app/components/gh-site-iframe.js

@@ -0,0 +1,20 @@
+import Component from '@ember/component';
+import {inject as service} from '@ember/service';
+
+export default Component.extend({
+    config: service(),
+
+    tagName: '',
+
+    didReceiveAttrs() {
+        // reset the src attribute each time the guid changes - allows for
+        // a click on the navigation item to reset back to the homepage
+        if (this.guid !== this._lastGuid) {
+            let iframe = document.querySelector('#site-frame');
+            if (iframe) {
+                iframe.src = `${this.config.get('blogUrl')}/`;
+            }
+        }
+        this._lastGuid = this.guid;
+    }
+});

ghost/admin/app/controllers/site.js

@@ -0,0 +1,6 @@
+import Controller from '@ember/controller';
+import {alias} from '@ember/object/computed';
+
+export default Controller.extend({
+    guid: alias('model')
+});

ghost/admin/app/routes/site.js

@@ -4,5 +4,9 @@ import styleBody from 'ghost-admin/mixins/style-body';
 export default AuthenticatedRoute.extend(styleBody, {
     titleToken: 'Site',
 
-    classNames: ['view-site']
+    classNames: ['view-site'],
+
+    model() {
+        return (new Date()).valueOf();
+    }
 });

ghost/admin/app/templates/components/gh-nav-menu.hbs

@@ -42,7 +42,9 @@
             {{gh-search-input class="gh-nav-search-input"}}
         </section>
         <ul class="gh-nav-list gh-nav-main">
-            <li>{{#link-to "site" data-test-nav="site"}}{{svg-jar "view-site-embed"}}View site{{/link-to}}</li>
+            <li {{action "transitionToOrRefreshSite" on="click"}}>
+                {{#link-to "site" data-test-nav="site" preventDefault=false}}{{svg-jar "view-site-embed"}}View site{{/link-to}}
+            </li>
         </ul>
         <ul class="gh-nav-list gh-nav-manage">
             <li class="gh-nav-list-h">Manage</li>

ghost/admin/app/templates/components/gh-site-iframe.hbs

@@ -0,0 +1,15 @@
+<iframe id="site-frame" class="site-frame" src="{{this.config.blogUrl}}/" frameborder="0" allowtransparency="true"></iframe>
+
+<style>
+.site-frame {
+    position: absolute;
+    top: 0;
+    right: 0;
+    bottom: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    border: none;
+    transform: translate3d(0, 0, 0);
+}
+</style>

ghost/admin/app/templates/site.hbs

@@ -1,15 +1 @@
-<iframe class="site-frame" src="{{config.blogUrl}}/" frameborder="0" allowtransparency="true"></iframe>
-
-<style>
-.site-frame {
-    position: absolute;
-    top: 0;
-    right: 0;
-    bottom: 0;
-    left: 0;
-    width: 100%;
-    height: 100%;
-    border: none;
-    transform: translate3d(0, 0, 0);
-}
-</style>
+<GhSiteIframe @guid={{this.guid}}></GhSiteIframe>