FEATURE: if full search returns no results, show google search form

app/assets/javascripts/discourse/components/google-search.js.es6

@@ -0,0 +1,13 @@
+import computed from "ember-addons/ember-computed-decorators";
+
+export default Ember.Component.extend({
+  classNames: ['google-search-form'],
+  classNameBindings: ['hidden:hidden'],
+
+  hidden: Ember.computed.alias('siteSettings.login_required'),
+
+  @computed
+  siteUrl() {
+    return `${location.protocol}//${location.host}${Discourse.getURL('/')}`;
+  }
+});

app/assets/javascripts/discourse/controllers/full-page-search.js.es6

@@ -87,6 +87,11 @@ export default Ember.Controller.extend({
     return escapeExpression(q);
   },
 
+  @computed('canCreateTopic', 'siteSettings.login_required')
+  showSuggestion(canCreateTopic, loginRequired) {
+    return canCreateTopic || !loginRequired;
+  },
+
   _searchOnSortChange: true,
 
   setSearchTerm(term) {

app/assets/javascripts/discourse/templates/components/google-search.hbs

@@ -0,0 +1,7 @@
+<div>
+  <form action='//google.com/search' id='google-search'>
+    <input type="text" name="q" value="{{searchTerm}}">
+    <input type='hidden' name="as_sitesearch" value="{{siteUrl}}">
+    <button class="btn btn-primary">{{i18n 'search.search_google_button'}}</button>
+  </form>
+</div>

app/assets/javascripts/discourse/templates/full-page-search.hbs

@@ -15,7 +15,9 @@
       {{/if}}
     </div>
 
+    {{#if hasResults}}
       {{create-topic-button canCreateTopic=canCreateTopic action=(action "createTopic" searchTerm)}}
+    {{/if}}
 
     {{#if canBulkSelect}}
       {{d-button icon="list" class="bulk-select" title="topics.bulk.toggle" action="toggleBulkSelect"}}
@@ -116,11 +118,25 @@
 
     {{#conditional-loading-spinner condition=loading }}
       {{#unless hasResults}}
-        <h3>
         {{#if searchActive}}
-              {{i18n "search.no_results"}}
+          <h3>{{i18n "search.no_results"}}</h3>
+
+          {{#if showSuggestion}}
+            <div class="no-results-suggestion">
+              {{i18n "search.cant_find"}}
+              {{#if canCreateTopic}}
+                <a href {{action "createTopic" searchTerm}}>{{i18n "search.start_new_topic"}}</a>
+                {{#unless siteSettings.login_required}}
+                  {{i18n "search.or_search_google"}}
+                {{/unless}}
+              {{else}}
+                {{i18n "search.search_google"}}
+              {{/if}}
+            </div>
+
+            {{google-search searchTerm=searchTerm}}
+          {{/if}}
         {{/if}}
-        </h3>
       {{/unless}}
 
       {{#if hasResults}}

app/assets/stylesheets/common/base/search.scss

@@ -121,6 +121,9 @@
   }
 }
 
+.no-results-suggestion {
+  margin-top: 30px;
+}
 .search-footer {
   margin-bottom: 30px;
 }
@@ -162,3 +165,7 @@
     margin-bottom: 4px;
   }
 }
+
+.google-search-form {
+  margin-top: 2em;
+}

config/locales/client.en.yml

@@ -1353,6 +1353,12 @@ en:
       post_format: "#{{post_number}} by {{username}}"
       results_page: "Search Results"
       more_results: "There are more results. Please narrow your search criteria."
+      cant_find: "Can't find what you're looking for?"
+      start_new_topic: "Why not create a topic?"
+      or_search_google: "Or use Google to search instead:"
+      search_google: "Try searching with Google instead:"
+      search_google_button: "Google"
+      search_google_title: "Search this site"
 
       context:
         user: "Search posts by @{{username}}"

test/javascripts/acceptance/search-full-test.js.es6

@@ -53,7 +53,10 @@ QUnit.test("perform various searches", assert => {
   fillIn('.search input.full-page-search', 'none');
   click('.search .btn-primary');
 
-  andThen(() => assert.ok(find('.fps-topic').length === 0), 'has no results');
+  andThen(() => {
+    assert.ok(find('.fps-topic').length === 0, 'has no results');
+    assert.ok(find('.no-results-suggestion .google-search-form'));
+  });
 
   fillIn('.search input.full-page-search', 'posts');
   click('.search .btn-primary');