WordPress Customizer: add contact details section

customizer.php

// Add theme customizer controls, settings, etc.
function kingdom_customize_register($wp_customize)
{
	/********************************************
	! define genric controls 
	*******************************************/	
	/**
	* create class to define textarea in Customizer
	*/
	class Kingdom_Customize_Textarea_Control extends WP_Customize_Control
	{
		public $type = 'textarea';
		public function render_content()
		{
			echo '<label>';
				echo '<span class="customize-control-title">';
					echo esc_html( $this->label );
				echo '</span>';
				echo '<textarea name="" id="" cols="" rows="2" class="widefat" ';
					$this->link();
				echo '>';
					esc_textarea( $this->value() ); 
				echo '</textarea>';
			echo '</label>';
		}
	}	

	/********************************************
	!  Contact Details
	*********************************************/
	/* add section */
	$wp_customize->add_section( 'kingdom_contact', array(
		'title' => __( 'Contact Details', 'kingdom' )
	));

	/**
	 * Address
	 */
	/* add setting */
	$wp_customize->add_setting('kingdom_address_setting', array(
		'default' => __( 'Your address', 'kingdom' )
	));
	/* add controls */
	$wp_customize->add_control( new Kingdom_Customize_Textarea_Control(
		$wp_customize,
		'kingdom_address_setting', 
		array(
			'label' => 'Address',
			'section' => 'kingdom_contact',
			'setting' => 'kingdom_address_setting'
		)
	));

	/**
	 * Phone
	 */
	/* add setting */
	$wp_customize->add_setting('kingdom_phone_setting', array(
		'default' => __( 'Your phone number', 'kingdom' )
	));
	/* add controls */
	$wp_customize->add_control( new Kingdom_Customize_Textarea_Control(
		$wp_customize,
		'kingdom_phone_setting', 
		array(
			'label' => 'Phone Number',
			'section' => 'kingdom_contact',
			'setting' => 'kingdom_phone_setting'
		)
	));

	/**
	 * Email
	 */
	/* add setting */
	$wp_customize->add_setting('kingdom_email_setting', array(
		'default' => __( 'Your email', 'kingdom' )
	));
	/* add controls */
	$wp_customize->add_control( new Kingdom_Customize_Textarea_Control(
		$wp_customize,
		'kingdom_email_setting', 
		array(
			'label' => 'Email',
			'section' => 'kingdom_contact',
			'setting' => 'kingdom_email_setting'
		)
	));
}
add_action('customize_register', 'kingdom_customize_register');

/********************************************
! add controls / content to theme 
*********************************************/
function kingdom_display_contact_details_in_header()
{
	$html = '';
	$html .= '<address>';
		// Address
		$html .= '<p class="address">';
			$html .= get_theme_mod( 'kingdom_address_setting', 'Your Address' );
		$html .= '</p><!-- /.address -->';

		// Phone
		$html .= '<p class="phone">';
			$html .=  get_theme_mod( 'kingdom_phone_setting', 'Your phone number' );
		$html .= '</p><!-- /.phone -->';

		// Email
		$html .= '<p class="email">';
			$email = get_theme_mod( 'kingdom_email_setting', 'Your email address' );
			$html .= '<a href="' . $email . ' ">';
				$html .= $email;
			$html .= '</a>';
		$html .= '</p><!-- /.email -->';
	$html .= '</address>';

	echo $html;
}
add_action('kingdom_in_header', 'kingdom_display_contact_details_in_header');

functions.php

load_template( get_template_directory() . '/includes/customizer.php' );

header.php

/* action hook for any content placed inside the right hand header, including the widget area. */

do_action ( 'kingdom_in_header' );