Example: add support for new schema.org type in Schema Premium plugin https://schema.press/introducing-schema-premium/

schema-premium-add-type.php

<?php //* do not include php tag

/**
 * @package Schema Premium - Class Schema New Type
 * @category Core
 * @author Hesham Zebida
 * @version 1.0.0
 */

// Exit if accessed directly
if ( ! defined( 'ABSPATH' ) ) exit;

if ( ! class_exists('Schema_WP_New_Type') ) :
	/**
	 * Schema Type
	 *
	 * @since 1.0.0
	 */
	class Schema_WP_New_Type {
		
		/** @var string Current Type */
    	protected $type = 'Type';
		
		/**
	 	* Constructor
	 	*
	 	* @since 1.0.0
	 	*/
		public function __construct () {
			
			$this->init();
		}
	
		/**
		* Init
		*
		* @since 1.0.0
	 	*/
		public function init() {
		
			add_filter( 'schema_premium_get_default_schemas', array( $this, 'schema_type' ) );
			add_filter( 'schema_premium_types', array( $this, 'schema_type_extend' ) );
		}
		
		/**
		* Get schema type label
		*
		* @since 1.0.0
		* @return array
		*/
		public function label() {
			
			return __('Type');
		}
		
		/**
		* Get schema type comment
		*
		* @since 1.0.0
		* @return array
		*/
		public function comment() {
			
			return __('An article, such as a news article or piece of investigative report. Newspapers and magazines have articles of many different types and this is intended to cover them all. (See also blog post).');
		}
		
		/**
		* Extend schema types
		*
		* @since 1.0.0
		* @return array
		*/
		public function schema_type_extend( $schema_types ) {
			
			$schema_types[$this->type] = array 
				(
					'label' => $this->label(),
					'value'	=> $this->type
				);
			
			return $schema_types;
		}
		
		/**
		* Get schema type
		*
		* @since 1.0.0
		* @return array
		*/
		public function schema_type( $schema ) {
      
			$schema[$this->type] = array (
          			'id' 		=> $this->type, 
          			'lable' 	=> $this->label(),
          			'comment' 	=> $this->comment(),
          			'properties'	=> $this->properties(),
          			'subtypes' 	=> $this->subtypes(),
			);
			
			return apply_filters( 'schema_Type', $schema );
		}
			
		/**
		* Get sub types
		*
		* @since 1.0.0
		* @return array
		*/
		public function subtypes() {}
		
		/**
		* Get properties
		*
		* @since 1.0.0
		* @return array
		*/
		public function properties() {}
		
		/**
		* Schema output
		*
		* @since 1.0.0
		* @return array
		*/
		public function schema_output( $post_id = null ) {}
	}
	
	new Schema_WP_New_Type();
	
endif;