Using CMB to create an Admin Theme Options Page

This class is an example of how you can use CMB to create an Admin Theme Options Page. Keep in mind that the self::$theme_options array can be added to and extended the same way you would in the cmb_meta_boxes filter. If you want to retrieve an option, use myprefix_get_option( 'test_text' ). Obviously replace all instances of myprefix with your own custom prefix.

<?php
/**
 * CMB Theme Options
 * @version 0.1.0
 */
class myprefix_Admin {

 	/**
 	 * Option key, and option page slug
 	 * @var string
 	 */
	private $key = 'myprefix_options';

	/**
	 * Array of metaboxes/fields
	 * @var array
	 */
	protected $option_metabox = array();

	/**
	 * Options Page title
	 * @var string
	 */
	protected $title = '';

	/**
	 * Options Page hook
	 * @var string
	 */
	protected $options_page = '';

	/**
	 * Constructor
	 * @since 0.1.0
	 */
	public function __construct() {
		// Set our title
		$this->title = __( 'Site Options', 'myprefix' );

		// Set our CMB fields
		$this->fields = array(
			array(
				'name' => __( 'Test Text', 'myprefix' ),
				'desc' => __( 'field description (optional)', 'myprefix' ),
				'id'   => 'test_text',
				'type' => 'text',
			),
			array(
				'name'    => __( 'Test Color Picker', 'myprefix' ),
				'desc'    => __( 'field description (optional)', 'myprefix' ),
				'id'      => 'test_colorpicker',
				'type'    => 'colorpicker',
				'default' => '#ffffff'
			),
		);
 	}

	/**
	 * Initiate our hooks
	 * @since 0.1.0
	 */
	public function hooks() {
		add_action( 'admin_init', array( $this, 'init' ) );
		add_action( 'admin_menu', array( $this, 'add_options_page' ) );
	}

	/**
	 * Register our setting to WP
	 * @since  0.1.0
	 */
	public function init() {
		register_setting( $this->key, $this->key );
	}

	/**
	 * Add menu options page
	 * @since 0.1.0
	 */
	public function add_options_page() {
		$this->options_page = add_menu_page( $this->title, $this->title, 'manage_options', $this->key, array( $this, 'admin_page_display' ) );
	}

	/**
	 * Admin page markup. Mostly handled by CMB
	 * @since  0.1.0
	 */
	public function admin_page_display() {
		?>
		<div class="wrap cmb_options_page <?php echo $this->key; ?>">
			<h2><?php echo esc_html( get_admin_page_title() ); ?></h2>
			<?php cmb_metabox_form( $this->option_metabox(), $this->key ); ?>
		</div>
		<?php
	}

	/**
	 * Defines the theme option metabox and field configuration
	 * @since  0.1.0
	 * @return array
	 */
	public function option_metabox() {
		return array(
			'id'         => 'option_metabox',
			'show_on'    => array( 'key' => 'options-page', 'value' => array( $this->key, ), ),
			'show_names' => true,
			'fields'     => $this->fields,
		);
	}

	/**
	 * Public getter method for retrieving protected/private variables
	 * @since  0.1.0
	 * @param  string  $field Field to retrieve
	 * @return mixed          Field value or exception is thrown
	 */
	public function __get( $field ) {

		// Allowed fields to retrieve
		if ( in_array( $field, array( 'key', 'fields', 'title', 'options_page' ), true ) ) {
			return $this->{$field};
		}
		if ( 'option_metabox' === $field ) {
			return $this->option_metabox();
		}

		throw new Exception( 'Invalid property: ' . $field );
	}

}

// Get it started
$myprefix_Admin = new myprefix_Admin();
$myprefix_Admin->hooks();

/**
 * Wrapper function around cmb_get_option
 * @since  0.1.0
 * @param  string  $key Options array key
 * @return mixed        Option value
 */
function myprefix_get_option( $key = '' ) {
	global $myprefix_Admin;
	return cmb_get_option( $myprefix_Admin->key, $key );
}

Link to gist: https://gist.github.com/jtsternberg/8601075