How to Add new Arguments to custom Control of customizer wordpress?

Question

The problem is that new arguments don't display at customizer.

at first, we extend WP_Customize_Control with this class:

class WP_Customize_Foo_Control extends WP_Customize_Control {
    public $type = 'foo';

    public function render_content() {
        echo $this->label;
        echo $this->description;

        echo $this->foo;  // <--- problem is here, it's not display
        echo $this->moo;  // <--- problem is here, it's not display
    }
}

at the next step we use add_setting and add_control to display our new control in static_front_page section.

$wp_customize->add_setting( 'foo_one', array(
    'type' => 'theme_mod',
    ));

$wp_customize->add_control( new WP_Customize_Foo_Control(
    $wp_customize,
    'foo_one',
    array(
        'label'         => 'Label',
        'description'   => 'desc',
        'type'          => 'foo',
        'section'       => 'static_front_page',

        'foo'           => 'John Doe',
        'moo'           => array('some','array','goes','here')

        ) 
    ));

problem is that, foo and moo arguments is not display in customizer.

Answer 1

If you check out the source of WP_Customize_Control::__construct:

public function __construct( $manager, $id, $args = array() ) {
    $keys = array_keys( get_object_vars( $this ) );
    foreach ( $keys as $key ) {
        if ( isset( $args[ $key ] ) ) {
            $this->$key = $args[ $key ];
        }
    }

    // [redacted]
 }

So you can see, in order for it pick up your custom arguments, they need to be declared as properties of your custom class:

class WP_Customize_Foo_Control extends WP_Customize_Control {
    public $foo;
    public $moo;
}