Problem
You have an Ember.TextField instance that you would like become focused after it’s been inserted.
Solution
Subclass Ember.TextField and define a method marked with
.on('didInsertElement'). Inside this method apply focus
to the text field by accessing the components’s jQuery $ property:
App.FocusInputComponent = Ember.TextField.extend({
becomeFocused: function() {
this.$().focus();
}.on('didInsertElement')
});For the component’s template:
Focus Input component!{{focus-input}}Discussion
Custom components provide a way to extend native HTML elements with new behavior like autofocusing.
Our App.FocusInputComponent is an extension of the Ember.TextField component
with a becomeFocused method added. After it is added to the DOM, every
component in Ember.js has access to an underlying jQuery object. This object wraps
the component’s element and provides a unified, cross-browser interface for DOM
manipulations like triggering focus.
Because we can only work with these DOM features once an Ember.js component has
been added to the DOM we need to wait for this event to occur. Component’s have a
didInsertElement event that is triggered when the component has been added to the
DOM.
By default Ember.js extends the native Function.prototype object to include a
number of additional functions, the on function among them. on gives us a declarative
syntax for signify that a method should be called when a specific event has fired. In this case,
we want to call our new becomeFocused method when the didInsertElement is fired for an instance
of our component.
Prototype extension can be disabled by setting the Ember.EXTEND_PROTOTYPES property to false.