gistfile1.js

Caption.ATTRS = {
   title_element: {},
   edit_input: {},
   edit_button: {},
   save_button: {}
}; 

Caption.HTML_PARSER = {
  title_element: '.view h3',
  edit_input: '.edit input',
  edit_button: '.view a[rel=edit]',
  save_button: '.edit button'
};

Y.extend(Caption, Y.Widget, {
  bindUI: function () {
    this.get('edit_button').on('click', this.edit, this);
    this.get('save_button').on('click', this.save, this);
  },

  edit: function () {
    this.get('edit_input').set('value', this.get('title_element').get('text'));
    this.get('contentBox').addClass('editing');
  },

  save: function () {
    this.get('title_element').set('text', this.get('edit_input').get('value'));
    this.get('contentBox').removeClass('editing');
  }
});

/* instantiation */

var caption = new Caption({contentBox: Y.one('#caption1')});
caption.render();