<?php
namespace Yoast\WP\SEO\Generators;
use WP_Block_Parser_Block;
use Yoast\WP\SEO\Context\Meta_Tags_Context;
use Yoast\WP\SEO\Generators\Schema\Abstract_Schema_Piece;
use Yoast\WP\SEO\Helpers\Schema\Replace_Vars_Helper;
use Yoast\WP\SEO\Surfaces\Helpers_Surface;
/**
* Class Schema_Generator.
*/
class Schema_Generator implements Generator_Interface {
/**
* The helpers surface.
*
* @var Helpers_Surface
*/
protected $helpers;
/**
* The Schema replace vars helper.
*
* @var Replace_Vars_Helper
*/
protected $schema_replace_vars_helper;
/**
* Generator constructor.
*
* @param Helpers_Surface $helpers The helpers surface.
* @param Replace_Vars_Helper $schema_replace_vars_helper The replace vars helper.
*/
public function __construct( Helpers_Surface $helpers, Replace_Vars_Helper $schema_replace_vars_helper ) {
$this->helpers = $helpers;
$this->schema_replace_vars_helper = $schema_replace_vars_helper;
}
/**
* Returns a Schema graph array.
*
* @param Meta_Tags_Context $context The meta tags context.
*
* @return array The graph.
*/
public function generate( Meta_Tags_Context $context ) {
$pieces = $this->get_graph_pieces( $context );
$this->schema_replace_vars_helper->register_replace_vars( $context );
foreach ( \array_keys( $context->blocks ) as $block_type ) {
/**
* Filter: 'wpseo_pre_schema_block_type_<block-type>' - Allows hooking things to change graph output based on the blocks on the page.
*
* @param WP_Block_Parser_Block[] $blocks All the blocks of this block type.
* @param Meta_Tags_Context $context A value object with context variables.
*/
\do_action( 'wpseo_pre_schema_block_type_' . $block_type, $context->blocks[ $block_type ], $context );
}
// Do a loop before everything else to inject the context and helpers.
foreach ( $pieces as $piece ) {
if ( \is_a( $piece, Abstract_Schema_Piece::class ) ) {
$piece->context = $context;
$piece->helpers = $this->helpers;
}
}
$pieces_to_generate = $this->filter_graph_pieces_to_generate( $pieces );
$graph = $this->generate_graph( $pieces_to_generate, $context );
$graph = $this->add_schema_blocks_graph_pieces( $graph, $context );
$graph = $this->finalize_graph( $graph, $context );
return [
'@context' => 'https://schema.org',
'@graph' => $graph,
];
}
/**
* Filters out any graph pieces that should not be generated.
* (Using the `wpseo_schema_needs_<graph_piece_identifier>` series of filters).
*
* @param array $graph_pieces The current list of graph pieces that we want to generate.
*
* @return array The graph pieces to generate.
*/
protected function filter_graph_pieces_to_generate( $graph_pieces ) {
$pieces_to_generate = [];
foreach ( $graph_pieces as $piece ) {
$identifier = \strtolower( \str_replace( 'Yoast\WP\SEO\Generators\Schema\\', '', \get_class( $piece ) ) );
if ( isset( $piece->identifier ) ) {
$identifier = $piece->identifier;
}
/**
* Filter: 'wpseo_schema_needs_<identifier>' - Allows changing which graph pieces we output.
*
* @param bool $is_needed Whether or not to show a graph piece.
*/
$is_needed = \apply_filters( 'wpseo_schema_needs_' . $identifier, $piece->is_needed() );
if ( ! $is_needed ) {
continue;
}
$pieces_to_generate[ $identifier ] = $piece;
}
return $pieces_to_generate;
}
/**
* Generates the schema graph.
*
* @param array $graph_piece_generators The schema graph pieces to generate.
* @param Meta_Tags_Context $context The meta tags context to use.
*
* @return array The generated schema graph.
*/
protected function generate_graph( $graph_piece_generators, $context ) {
$graph = [];
foreach ( $graph_piece_generators as $identifier => $graph_piece_generator ) {
$graph_pieces = $graph_piece_generator->generate();
// If only a single graph piece was returned.
if ( $graph_pieces !== false && \array_key_exists( '@type', $graph_pieces ) ) {
$graph_pieces = [ $graph_pieces ];
}
if ( ! \is_array( $graph_pieces ) ) {
continue;
}
foreach ( $graph_pieces as $graph_piece ) {
/**
* Filter: 'wpseo_schema_<identifier>' - Allows changing graph piece output.
* This filter can be called with either an identifier or a block type (see `add_schema_blocks_graph_pieces()`).
*
* @param array $graph_piece The graph piece to filter.
* @param Meta_Tags_Context $context A value object with context variables.
* @param Abstract_Schema_Piece $graph_piece_generator A value object with context variables.
* @param Abstract_Schema_Piece[] $graph_piece_generators A value object with context variables.
*/
$graph_piece = \apply_filters( 'wpseo_schema_' . $identifier, $graph_piece, $context, $graph_piece_generator, $graph_piece_generators );
$graph_piece = $this->type_filter( $graph_piece, $identifier, $context, $graph_piece_generator, $graph_piece_generators );
$graph_piece = $this->validate_type( $graph_piece );
if ( \is_array( $graph_piece ) ) {
$graph[] = $graph_piece;
}
}
}
/**
* Filter: 'wpseo_schema_graph' - Allows changing graph output.
*
* @param array $graph The graph to filter.
* @param Meta_Tags_Context $context A value object with context variables.
*/
$graph = \apply_filters( 'wpseo_schema_graph', $graph, $context );
return $graph;
}
/**
* Adds schema graph pieces from Gutenberg blocks on the current page to
* the given schema graph.
*
* Think of blocks like the Yoast FAQ block or the How To block.
*
* @param array $graph The current schema graph.
* @param Meta_Tags_Context $context The meta tags context.
*
* @return array The graph with the schema blocks graph pieces added.
*/
protected function add_schema_blocks_graph_pieces( $graph, $context ) {
foreach ( $context->blocks as $block_type => $blocks ) {
foreach ( $blocks as $block ) {
$block_type = \strtolower( $block['blockName'] );
/**
* Filter: 'wpseo_schema_block_<block-type>'.
* This filter is documented in the `generate_graph()` function in this class.
*/
$graph = \apply_filters( 'wpseo_schema_block_' . $block_type, $graph, $block, $context );
if ( isset( $block['attrs']['yoast-schema'] ) ) {
$graph[] = $this->schema_replace_vars_helper->replace( $block['attrs']['yoast-schema'], $context->presentation );
}
}
}
return $graph;
}
/**
* Finalizes the schema graph after all filtering is done.
*
* @param array $graph The current schema graph.
* @param Meta_Tags_Context $context The meta tags context.
*
* @return array The schema graph.
*/
protected function finalize_graph( $graph, $context ) {
$graph = $this->remove_empty_breadcrumb( $graph, $context );
return $graph;
}
/**
* Removes the breadcrumb schema if empty.
*
* @param array $graph The current schema graph.
* @param Meta_Tags_Context $context The meta tags context.
*
* @return array The schema graph with empty breadcrumbs taken out.
*/
protected function remove_empty_breadcrumb( $graph, $context ) {
if ( $this->helpers->current_page->is_home_static_page() || $this->helpers->current_page->is_home_posts_page() ) {
return $graph;
}
// Remove the breadcrumb piece, if it's empty.
$index_to_remove = 0;
foreach ( $graph as $key => $piece ) {
if ( \in_array( 'BreadcrumbList', $this->get_type_from_piece( $piece ), true ) ) {
if ( isset( $piece['itemListElement'] ) && \is_array( $piece['itemListElement'] ) && \count( $piece['itemListElement'] ) === 1 ) {
$index_to_remove = $key;
break;
}
}
}
// If the breadcrumb piece has been removed, we should remove its reference from the WebPage node.
if ( $index_to_remove !== 0 ) {
\array_splice( $graph, $index_to_remove, 1 );
// Get the type of the WebPage node.
$webpage_types = \is_array( $context->schema_page_type ) ? $context->schema_page_type : [ $context->schema_page_type ];
foreach ( $graph as $key => $piece ) {
if ( ! empty( \array_intersect( $webpage_types, $this->get_type_from_piece( $piece ) ) ) && isset( $piece['breadcrumb'] ) ) {
unset( $piece['breadcrumb'] );
$graph[ $key ] = $piece;
}
}
}
return $graph;
}
/**
* Adapts the WebPage graph piece for password-protected posts.
*
* It should only have certain whitelisted properties.
* The type should always be WebPage.
*
* @param array $graph_piece The WebPage graph piece that should be adapted for password-protected posts.
*
* @return array The WebPage graph piece that has been adapted for password-protected posts.
*/
public function protected_webpage_schema( $graph_piece ) {
$properties_to_show = \array_flip(
[
'@type',
'@id',
'url',
'name',
'isPartOf',
'inLanguage',
'datePublished',
'dateModified',
'breadcrumb',
],
);
$graph_piece = \array_intersect_key( $graph_piece, $properties_to_show );
$graph_piece['@type'] = 'WebPage';
return $graph_piece;
}
/**
* Gets all the graph pieces we need.
*
* @param Meta_Tags_Context $context The meta tags context.
*
* @return Abstract_Schema_Piece[] A filtered array of graph pieces.
*/
protected function get_graph_pieces( $context ) {
if ( $context->indexable->object_type === 'post' && \post_password_required( $context->post ) ) {
$schema_pieces = [
new Schema\WebPage(),
new Schema\Website(),
new Schema\Organization(),
];
\add_filter( 'wpseo_schema_webpage', [ $this, 'protected_webpage_schema' ], 1 );
}
else {
$schema_pieces = [
new Schema\Article(),
new Schema\WebPage(),
new Schema\Main_Image(),
new Schema\Breadcrumb(),
new Schema\Website(),
new Schema\Organization(),
new Schema\Person(),
new Schema\Author(),
new Schema\FAQ(),
new Schema\HowTo(),
];
}
/**
* Filter: 'wpseo_schema_graph_pieces' - Allows adding pieces to the graph.
*
* @param array $pieces The schema pieces.
* @param Meta_Tags_Context $context An object with context variables.
*/
return \apply_filters( 'wpseo_schema_graph_pieces', $schema_pieces, $context );
}
/**
* Allows filtering the graph piece by its schema type.
*
* Note: We removed the Abstract_Schema_Piece type-hint from the $graph_piece_generator argument, because
* it caused conflicts with old code, Yoast SEO Video specifically.
*
* @param array $graph_piece The graph piece we're filtering.
* @param string $identifier The identifier of the graph piece that is being filtered.
* @param Meta_Tags_Context $context The meta tags context.
* @param Abstract_Schema_Piece $graph_piece_generator A value object with context variables.
* @param Abstract_Schema_Piece[] $graph_piece_generators A value object with context variables.
*
* @return array The filtered graph piece.
*/
private function type_filter( $graph_piece, $identifier, Meta_Tags_Context $context, $graph_piece_generator, array $graph_piece_generators ) {
$types = $this->get_type_from_piece( $graph_piece );
foreach ( $types as $type ) {
$type = \strtolower( $type );
// Prevent running the same filter twice. This makes sure we run f/i. for 'author' and for 'person'.
if ( $type && $type !== $identifier ) {
/**
* Filter: 'wpseo_schema_<type>' - Allows changing graph piece output by @type.
*
* @param array $graph_piece The graph piece to filter.
* @param Meta_Tags_Context $context A value object with context variables.
* @param Abstract_Schema_Piece $graph_piece_generator A value object with context variables.
* @param Abstract_Schema_Piece[] $graph_piece_generators A value object with context variables.
*/
$graph_piece = \apply_filters( 'wpseo_schema_' . $type, $graph_piece, $context, $graph_piece_generator, $graph_piece_generators );
}
}
return $graph_piece;
}
/**
* Retrieves the type from a graph piece.
*
* @param array $piece The graph piece.
*
* @return array An array of the piece's types.
*/
private function get_type_from_piece( $piece ) {
if ( isset( $piece['@type'] ) ) {
if ( \is_array( $piece['@type'] ) ) {
// Return as-is, but remove unusable values, like sub-arrays, objects, null.
return \array_filter( $piece['@type'], 'is_string' );
}
return [ $piece['@type'] ];
}
return [];
}
/**
* Validates a graph piece's type.
*
* When the type is an array:
* - Ensure the values are unique.
* - Only 1 value? Use that value without the array wrapping.
*
* @param array $piece The graph piece.
*
* @return array The graph piece.
*/
private function validate_type( $piece ) {
if ( ! isset( $piece['@type'] ) ) {
// No type to validate.
return $piece;
}
// If it is not an array, we can return immediately.
if ( ! \is_array( $piece['@type'] ) ) {
return $piece;
}
/*
* Ensure the types are unique.
* Use array_values to reset the indices (e.g. no 0, 2 because 1 was a duplicate).
*/
$piece['@type'] = \array_values( \array_unique( $piece['@type'] ) );
// Use the first value if there is only 1 type.
if ( \count( $piece['@type'] ) === 1 ) {
$piece['@type'] = \reset( $piece['@type'] );
}
return $piece;
}
}