PHP error with `template_include` filter hook

Fatal error:
Uncaught TypeError:
Argument 1 passed to WebManDesign\Eimear\Plugin\WooCommerce\Single::product_page_template_load() must be of the type string, null given,
called in C:\wamp64\www\eimear\wp-includes\class-wp-hook.php on line 287
and defined in C:\wamp64\www\eimear\wp-content\themes\eimear\includes\Plugin\WooCommerce\Single.php on line 168

– But this error is for WooCommerce single product page.

WCFM does not have any effect on this page templates. This is no way relate to store page and WCFMmp_Rewrites->store_template()

Still if you thing some changes required then know me.

function store_template( $template ) {
		global $WCFM, $WCFMmp;
		
		if ( !WCFMmp_Dependencies::woocommerce_plugin_active_check() ) {
			return $template;
		}
		
		if( $WCFMmp->store_template_loaded ) return $template;
		
		$store_name = get_query_var( $this->wcfm_store_url );

		if ( !empty( $store_name ) ) {
			$store_user = get_user_by( 'slug', $store_name );
			
			remove_filter( 'template_include', array( 'WC_Template_Loader', 'template_loader' ) );
			$WCFMmp->store_template_loaded = true;
			
			// no user found
			if ( ! $store_user ) {
				return get_404_template();
			}

			// check if the user is seller
			if ( ! wcfm_is_vendor( $store_user->ID ) ) {
				return get_404_template();
			}
			
			// Disable Store URL Visit
			if( apply_filters( 'wcfm_is_disable_store_url_access', false ) ) {
				wp_safe_redirect( get_permalink( wc_get_page_id( 'shop' ) ) );
				exit;
			}
			
			// Check is store Online
			$is_store_offline = get_user_meta( $store_user->ID, '_wcfm_store_offline', true );
			$is_store_offline = apply_filters( 'wcfmmp_is_store_offline', $is_store_offline, $store_user->ID );
			if ( $is_store_offline ) {
				return get_404_template();
			}
			
			// WCFM Marketplace Elementor Compatibility
			$wcfmem_template = apply_filters( 'wcfmem_locate_store_template', '' );
			if( $wcfmem_template ) return $wcfmem_template;
			
			// Dive Theme Builder Support
			if( function_exists( 'et_theme_builder_frontend_override_template' ) ) {
				$layouts         = et_theme_builder_get_template_layouts();
				$override_header = et_theme_builder_overrides_layout( ET_THEME_BUILDER_HEADER_LAYOUT_POST_TYPE );
				$override_footer = et_theme_builder_overrides_layout( ET_THEME_BUILDER_FOOTER_LAYOUT_POST_TYPE );
				if ( $override_header || $override_footer ) {
					add_action( 'get_header', 'et_theme_builder_frontend_override_header' );
					add_action( 'get_footer', 'et_theme_builder_frontend_override_footer' );
						
					et_theme_builder_frontend_enqueue_styles( $layouts );
				}
			}
			
			if ( get_query_var( $this->store_endpoint('about') ) ) {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => 'about' ) );
			} elseif ( get_query_var( $this->store_endpoint('policies') ) ) {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => 'policies' ) );
			} elseif ( get_query_var( $this->store_endpoint('reviews') ) ) {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => 'reviews' ) );
			} elseif ( get_query_var( $this->store_endpoint('followers') ) ) {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => 'followers' ) );
			} elseif ( get_query_var( $this->store_endpoint('followings') ) ) {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => 'followings' ) );
			} elseif ( get_query_var( $this->store_endpoint('articles') ) ) {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => 'articles' ) );
			} else {
				return $WCFMmp->template->get_template( 'store/wcfmmp-view-store.php', array( 'store_tab' => apply_filters( 'wcfmmp_store_default_query_vars', apply_filters( 'wcfmp_store_default_query_vars', 'products', $store_user->ID ), 'products', $store_user->ID ) ) );
			}
		}

		return $template;
	}

Hi,

– But this error is for WooCommerce single product page. WCFM does not have any effect on this page templates. This is no way relate to store page and WCFMmp_Rewrites->store_template()

I’m sorry, but it is related and the issue is not for WooCommerce single product page. It’s just a name of the theme method that makes you think so.

To explain, WordPress template_include filter hook is being executed on every front-end page. The WebManDesign\Eimear\Plugin\WooCommerce\Single::product_page_template_load() method is the first one that is being queued to the filter right after your plugin filters it. And as your plugin outputs NULL instead of string and the WebManDesign\Eimear\Plugin\WooCommerce\Single::product_page_template_load() receives NULL while it strictly expects string (as according to WordPress documentation and code) the PHP throws error. It has nothing to do with WooCommerce single product page or any other page for that matter.

Still if you thing some changes required then know me.

I’ve checked your plugin code and found the source of the issue:

All of your $WCFMmp->template->get_template() methods return NULL. Actually, I’m not really sure why you are using theme with return $WCFMmp->template->get_template(...); as the method does not even contain any return statement within itself and that’s actually why it defaults to returning NULL in PHP.

To fix the issue, please add return (string) $located; as the last line into the WCFMmp_Template->get_template() method within core/class-wcfmmp-template.php file.

Also, I have found similar method WCFM_Template->get_template() in core/class-wcfm-template.php file of your other plugin wc-frontend-manager. The issue is the same: the method does not return anything, which is interpreted by PHP as NULL. If these methods are used in WordPress’ template_include filter hook, they should always return string.

Please fix all of such methods in all of your plugins (where applicable).

Thank you.

Best regards,

Oliver

Hi guys,

Any update on this please?

Thanks and regards,

Oliver