Episode Details

class Episode_Details_Meta_Box {

	public function __construct() {

		if ( is_admin() ) {
			add_action( 'load-post.php',     array( $this, 'init_metabox' ) );
			add_action( 'load-post-new.php', array( $this, 'init_metabox' ) );
		}

	}

	public function init_metabox() {

		add_action( 'add_meta_boxes',        array( $this, 'add_metabox' )         );
		add_action( 'save_post',             array( $this, 'save_metabox' ), 10, 2 );

	}

	public function add_metabox() {

		add_meta_box(
			'episode_details',
			__( 'Episode Details', 'episcopal' ),
			array( $this, 'render_metabox' ),
			'episode',
			'normal',
			'default'
		);

	}

	public function render_metabox( $post ) {

		// Add nonce for security and authentication.
		wp_nonce_field( 'episode_nonce_action', 'episode_nonce' );

		// Retrieve an existing value from the database.
		$episode_episode_subtitle = get_post_meta( $post->ID, 'episode_episode_subtitle', true );
		$episode_season_number = get_post_meta( $post->ID, 'episode_season_number', true );
		$episode_episode_number = get_post_meta( $post->ID, 'episode_episode_number', true );
		$episode_podcast = get_post_meta( $post->ID, 'episode_podcast', true );

		// Set default values.
		if( empty( $episode_episode_subtitle ) ) $episode_episode_subtitle = '';
		if( empty( $episode_season_number ) ) $episode_season_number = '';
		if( empty( $episode_episode_number ) ) $episode_episode_number = '';
		if( empty( $episode_podcast ) ) $episode_podcast = '';

		// Form fields.
		echo '<table class="form-table">';

		echo '	<tr>';
		echo '		<th><label for="episode_episode_subtitle" class="episode_episode_subtitle_label">' . __( 'Episode Subtitle', 'episcopal' ) . '</label></th>';
		echo '		<td>';
		echo '			<textarea id="episode_episode_subtitle" name="episode_episode_subtitle" class="episode_episode_subtitle_field" placeholder="' . esc_attr__( '', 'episcopal' ) . '">' . $episode_episode_subtitle . '</textarea>';
		echo '			<p class="description">' . __( 'Subtitle appears in the iTunes Description', 'episcopal' ) . '</p>';
		echo '		</td>';
		echo '	</tr>';

		echo '	<tr>';
		echo '		<th><label for="episode_season_number" class="episode_season_number_label">' . __( 'Season Number', 'episcopal' ) . '</label></th>';
		echo '		<td>';
		echo '			<input type="number" id="episode_season_number" name="episode_season_number" class="episode_season_number_field" placeholder="' . esc_attr__( '', 'episcopal' ) . '" value="' . esc_attr( $episode_season_number ) . '">';
		echo '		</td>';
		echo '	</tr>';

		echo '	<tr>';
		echo '		<th><label for="episode_episode_number" class="episode_episode_number_label">' . __( 'Episode Number', 'episcopal' ) . '</label></th>';
		echo '		<td>';
		echo '			<input type="number" id="episode_episode_number" name="episode_episode_number" class="episode_episode_number_field" placeholder="' . esc_attr__( '', 'episcopal' ) . '" value="' . esc_attr( $episode_episode_number ) . '">';
		echo '		</td>';
		echo '	</tr>';

		echo '	<tr>';
		echo '		<th><label for="episode_podcast" class="episode_podcast_label">' . __( 'Podcasts', 'episcopal' ) . '</label></th>';
		echo '		<td>';
		wp_dropdown_pages( array( 'id' => 'episode_podcast', 'name' => 'episode_podcast', 'class' => 'episode_podcast_field', 'selected' => $episode_podcast ) );
		echo '		</td>';
		echo '	</tr>';

		echo '</table>';

	}

	public function save_metabox( $post_id, $post ) {

		// Add nonce for security and authentication.
		$nonce_name   = isset( $_POST['episode_nonce'] ) ? $_POST['episode_nonce'] : '';
		$nonce_action = 'episode_nonce_action';

		// Check if a nonce is set.
		if ( ! isset( $nonce_name ) )
			return;

		// Check if a nonce is valid.
		if ( ! wp_verify_nonce( $nonce_name, $nonce_action ) )
			return;

		// Check if the user has permissions to save data.
		if ( ! current_user_can( 'edit_post', $post_id ) )
			return;

		// Check if it's not an autosave.
		if ( wp_is_post_autosave( $post_id ) )
			return;

		// Sanitize user input.
		$episode_new_episode_subtitle = isset( $_POST[ 'episode_episode_subtitle' ] ) ? sanitize_text_field( $_POST[ 'episode_episode_subtitle' ] ) : '';
		$episode_new_season_number = isset( $_POST[ 'episode_season_number' ] ) ? floatval( $_POST[ 'episode_season_number' ] ) : '';
		$episode_new_episode_number = isset( $_POST[ 'episode_episode_number' ] ) ? floatval( $_POST[ 'episode_episode_number' ] ) : '';
		$episode_new_podcast = isset( $_POST[ 'episode_podcast' ] ) ? sanitize_text_field( $_POST[ 'episode_podcast' ] ) : '';

		// Update the meta field in the database.
		update_post_meta( $post_id, 'episode_episode_subtitle', $episode_new_episode_subtitle );
		update_post_meta( $post_id, 'episode_season_number', $episode_new_season_number );
		update_post_meta( $post_id, 'episode_episode_number', $episode_new_episode_number );
		update_post_meta( $post_id, 'episode_podcast', $episode_new_podcast );

	}

}

new Episode_Details_Meta_Box;