UX: Autofocus when input is empty.

app/assets/javascripts/discourse/components/search-text-field.js.es6

@@ -9,5 +9,9 @@ export default TextField.extend({
 
   focusIn: function() {
     Em.run.later(() => { this.$().select(); });
-  }
+  },
+
+  becomeFocused: function() {
+    if (this.get('hasAutofocus')) this.$().focus();
+  }.on('didInsertElement')
 });

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

@@ -13,6 +13,11 @@ export default Ember.Controller.extend({
   context_id: null,
   context: null,
 
+  @computed('q')
+  hasAutofocus(q) {
+    return Em.isEmpty(q);
+  },
+
   @computed('skip_context', 'context')
   searchContextEnabled: {
     get(skip,context){

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

@@ -1,5 +1,5 @@
 <div class="search row clearfix">
-  {{search-text-field value=searchTerm class="input-xxlarge search no-blur" action="search"}}
+  {{search-text-field value=searchTerm class="input-xxlarge search no-blur" action="search" hasAutofocus=hasAutofocus}}
   {{d-button action="search" icon="search" class="btn-primary" disabled=isNotValidSearchTerm}}
   {{#if canBulkSelect}}
     {{#if model.posts}}