Source

File: wp-includes/class-wp-post-type.php

public function set_props( $args ) {
		$args = wp_parse_args( $args );

		/**
		 * Filters the arguments for registering a post type.
		 *
		 * @since 4.4.0
		 *
		 * @param array  $args      Array of arguments for registering a post type.
		 * @param string $post_type Post type key.
		 */
		$args = apply_filters( 'register_post_type_args', $args, $this->name );

		$has_edit_link = ! empty( $args['_edit_link'] );

		// Args prefixed with an underscore are reserved for internal use.
		$defaults = array(
			'labels'                => array(),
			'description'           => '',
			'public'                => false,
			'hierarchical'          => false,
			'exclude_from_search'   => null,
			'publicly_queryable'    => null,
			'show_ui'               => null,
			'show_in_menu'          => null,
			'show_in_nav_menus'     => null,
			'show_in_admin_bar'     => null,
			'menu_position'         => null,
			'menu_icon'             => null,
			'capability_type'       => 'post',
			'capabilities'          => array(),
			'map_meta_cap'          => null,
			'supports'              => array(),
			'register_meta_box_cb'  => null,
			'taxonomies'            => array(),
			'has_archive'           => false,
			'rewrite'               => true,
			'query_var'             => true,
			'can_export'            => true,
			'delete_with_user'      => null,
			'show_in_rest'          => false,
			'rest_base'             => false,
			'rest_controller_class' => false,
			'_builtin'              => false,
			'_edit_link'            => 'post.php?post=%d',
		);

		$args = array_merge( $defaults, $args );

		$args['name'] = $this->name;

		// If not set, default to the setting for 'public'.
		if ( null === $args['publicly_queryable'] ) {
			$args['publicly_queryable'] = $args['public'];
		}

		// If not set, default to the setting for 'public'.
		if ( null === $args['show_ui'] ) {
			$args['show_ui'] = $args['public'];
		}

		// If not set, default to the setting for 'show_ui'.
		if ( null === $args['show_in_menu'] || ! $args['show_ui'] ) {
			$args['show_in_menu'] = $args['show_ui'];
		}

		// If not set, default to the setting for 'show_in_menu'.
		if ( null === $args['show_in_admin_bar'] ) {
			$args['show_in_admin_bar'] = (bool) $args['show_in_menu'];
		}

		// If not set, default to the setting for 'public'.
		if ( null === $args['show_in_nav_menus'] ) {
			$args['show_in_nav_menus'] = $args['public'];
		}

		// If not set, default to true if not public, false if public.
		if ( null === $args['exclude_from_search'] ) {
			$args['exclude_from_search'] = ! $args['public'];
		}

		// Back compat with quirky handling in version 3.0. #14122.
		if ( empty( $args['capabilities'] )
			&& null === $args['map_meta_cap'] && in_array( $args['capability_type'], array( 'post', 'page' ), true )
		) {
			$args['map_meta_cap'] = true;
		}

		// If not set, default to false.
		if ( null === $args['map_meta_cap'] ) {
			$args['map_meta_cap'] = false;
		}

		// If there's no specified edit link and no UI, remove the edit link.
		if ( ! $args['show_ui'] && ! $has_edit_link ) {
			$args['_edit_link'] = '';
		}

		$this->cap = get_post_type_capabilities( (object) $args );
		unset( $args['capabilities'] );

		if ( is_array( $args['capability_type'] ) ) {
			$args['capability_type'] = $args['capability_type'][0];
		}

		if ( false !== $args['query_var'] ) {
			if ( true === $args['query_var'] ) {
				$args['query_var'] = $this->name;
			} else {
				$args['query_var'] = sanitize_title_with_dashes( $args['query_var'] );
			}
		}

		if ( false !== $args['rewrite'] && ( is_admin() || get_option( 'permalink_structure' ) ) ) {
			if ( ! is_array( $args['rewrite'] ) ) {
				$args['rewrite'] = array();
			}
			if ( empty( $args['rewrite']['slug'] ) ) {
				$args['rewrite']['slug'] = $this->name;
			}
			if ( ! isset( $args['rewrite']['with_front'] ) ) {
				$args['rewrite']['with_front'] = true;
			}
			if ( ! isset( $args['rewrite']['pages'] ) ) {
				$args['rewrite']['pages'] = true;
			}
			if ( ! isset( $args['rewrite']['feeds'] ) || ! $args['has_archive'] ) {
				$args['rewrite']['feeds'] = (bool) $args['has_archive'];
			}
			if ( ! isset( $args['rewrite']['ep_mask'] ) ) {
				if ( isset( $args['permalink_epmask'] ) ) {
					$args['rewrite']['ep_mask'] = $args['permalink_epmask'];
				} else {
					$args['rewrite']['ep_mask'] = EP_PERMALINK;
				}
			}
		}

		foreach ( $args as $property_name => $property_value ) {
			$this->$property_name = $property_value;
		}

		$this->labels = get_post_type_labels( $this );
		$this->label  = $this->labels->name;
	}