Sidebar_Meta

/**
 * Generated by the WordPress Meta Box Generator
 */
class Rational_Meta_Box {
	private $screens = array(
		'post',
		'page',
	);
	private $fields = array(
		array(
			'id' => 'radio',
			'label' => 'Select the sidebar layout you would like for this post/page.',
			'type' => 'radio',
			'default' => '_default',
			'options' => array(
				'_default' => 'Default',
				'right_sidebar' => 'Content | Sidebar',
				'left_sidebar' => 'Sidebar | Content',
				'sidebars_right' => 'Content | Sidebar | Sidebar',
				'sidebars_left' => 'Sidebar | Sidebar | Content',
				'both_sidebars' => 'Sidebar | Content | Sidebar',
				'no_sidebars' => 'Full Width (No Sidebars)',
			),
		),
	);

	/**
	 * Class construct method. Adds actions to their respective WordPress hooks.
	 */
	public function __construct() {
		add_action( 'add_meta_boxes', array( $this, 'add_meta_boxes' ) );
		add_action( 'save_post', array( $this, 'save_post' ) );
	}

	/**
	 * Hooks into WordPress' add_meta_boxes function.
	 * Goes through screens (post types) and adds the meta box.
	 */
	public function add_meta_boxes() {
		foreach ( $this->screens as $screen ) {
			add_meta_box(
				'sidebar-layout',
				__( 'Sidebar Layout', 'themename' ),
				array( $this, 'add_meta_box_callback' ),
				$screen,
				'side',
				'default'
			);
		}
	}

	/**
	 * Generates the HTML for the meta box
	 * 
	 * @param object $post WordPress post object
	 */
	public function add_meta_box_callback( $post ) {
		wp_nonce_field( 'sidebar_layout_data', 'sidebar_layout_nonce' );
		$this->generate_fields( $post );
	}

	/**
	 * Generates the field's HTML for the meta box.
	 */
	public function generate_fields( $post ) {
		$output = '';
		foreach ( $this->fields as $field ) {
			$label = '<label for="' . $field['id'] . '">' . $field['label'] . '</label>';
			$db_value = get_post_meta( $post->ID, 'sidebar_layout_' . $field['id'], true );
			if ( empty( $db_value ) )
			$db_value = $field['default'];
			switch ( $field['type'] ) {
				case 'radio':
					$input = '<fieldset>';
					$input .= '<legend class="screen-reader-text">' . $field['label'] . '</legend>';
					$i = 0;
					foreach ( $field['options'] as $key => $value ) {
						$field_value = !is_numeric( $key ) ? $key : $value;
						$input .= sprintf(
							'<label><input %s id="%s" name="%s" type="radio" value="%s"> %s</label>%s',
							$db_value === $field_value ? 'checked' : '',
							$field['id'],
							$field['id'],
							$field_value,
							$value,
							$i < count( $field['options'] ) - 1 ? '<br>' : ''
						);
						$i++;
					}
					$input .= '</fieldset>';
					break;
				default:
					$input = sprintf(
						'<input id="%s" name="%s" type="%s" value="%s">',
						$field['id'],
						$field['id'],
						$field['type'],
						$db_value
					);
			}
			$output .= '<p>' . $label . '<br>' . $input . '</p>';
		}
		echo $output;
	}

	/**
	 * Hooks into WordPress' save_post function
	 */
	public function save_post( $post_id ) {
		if ( ! isset( $_POST['sidebar_layout_nonce'] ) )
			return $post_id;

		$nonce = $_POST['sidebar_layout_nonce'];
		if ( !wp_verify_nonce( $nonce, 'sidebar_layout_data' ) )
			return $post_id;

		if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
			return $post_id;

		foreach ( $this->fields as $field ) {
			if ( isset( $_POST[ $field['id'] ] ) ) {
				switch ( $field['type'] ) {
					case 'email':
						$_POST[ $field['id'] ] = sanitize_email( $_POST[ $field['id'] ] );
						break;
					case 'text':
						$_POST[ $field['id'] ] = sanitize_text_field( $_POST[ $field['id'] ] );
						break;
				}
				update_post_meta( $post_id, 'sidebar_layout_' . $field['id'], $_POST[ $field['id'] ] );
			} else if ( $field['type'] === 'checkbox' ) {
				update_post_meta( $post_id, 'sidebar_layout_' . $field['id'], '0' );
			}
		}
	}
}
new Rational_Meta_Box;