<?php
/**
* ElasticPress related posts feature
*
* @since 2.1
* @package elasticpress
*/
namespace ElasticPress\Feature\RelatedPosts;
use WP_Query;
use ElasticPress\Elasticsearch;
use ElasticPress\Feature;
use ElasticPress\REST;
use ElasticPress\Utils;
/**
* Related posts feature class
*/
class RelatedPosts extends Feature {
/**
* Initialize feature setting it's config
*
* @since 3.0
*/
public function __construct() {
$this->slug = 'related_posts';
$this->requires_install_reindex = false;
parent::__construct();
}
/**
* Sets i18n strings.
*
* @return void
* @since 5.2.0
*/
public function set_i18n_strings(): void {
$this->title = esc_html__( 'Related Posts', 'elasticpress' );
$this->summary = '<p>' . __( 'Instantly deliver engaging and precise related content with no impact on site performance. Output related content using our block or directly in your theme using our <a href="https://www.elasticpress.io/documentation/article/related-posts-api/">API functions</a>.', 'elasticpress' ) . '</p>';
$this->docs_url = __( 'https://www.elasticpress.io/documentation/article/configuring-elasticpress-via-the-plugin-dashboard/#related-posts', 'elasticpress' );
}
/**
* Format args for related posts
*
* @param array $formatted_args Formatted ES args
* @param array $args WP_Query args
* @return array
*/
public function formatted_args( $formatted_args, $args ) {
if ( ! empty( $args['more_like'] ) ) {
// lets compare ES version to see if new MLT structure applies
$new_mlt = version_compare( (string) Elasticsearch::factory()->get_elasticsearch_version(), 6.0, '>=' );
if ( $new_mlt && is_array( $args['more_like'] ) ) {
foreach ( $args['more_like'] as $id ) {
$ids[] = array( '_id' => $id );
}
} elseif ( $new_mlt && ! is_array( $args['more_like'] ) ) {
$ids = array( '_id' => $args['more_like'] );
} else {
$ids = is_array( $args['more_like'] ) ? $args['more_like'] : array( $args['more_like'] );
}
$mlt_key = ( $new_mlt ) ? 'like' : 'ids';
$formatted_args['query'] = array(
'more_like_this' => array(
$mlt_key => $ids,
/**
* Filter fields used to determine related posts
*
* @hook ep_related_posts_fields
* @param {array} $fields Related post fields
* @return {array} New fields
*/
'fields' => apply_filters(
'ep_related_posts_fields',
array(
'post_title',
'post_content',
'terms.post_tag.name',
)
),
/**
* Filter related posts minimum term frequency
*
* @hook ep_related_posts_min_term_freq
* @param {int} $minimum Minimum term frequency
* @return {array} New value
*/
'min_term_freq' => apply_filters( 'ep_related_posts_min_term_freq', 1 ),
/**
* Filter related posts maximum query terms
*
* @hook ep_related_posts_max_query_terms
* @param {int} $maximum Maximum query terms
* @return {array} New value
*/
'max_query_terms' => apply_filters( 'ep_related_posts_max_query_terms', 12 ),
/**
* Filter related posts minimum document frequency
*
* @hook ep_related_posts_min_doc_freq
* @param {int} $minimum Minimum document frequency
* @return {array} New value
*/
'min_doc_freq' => apply_filters( 'ep_related_posts_min_doc_freq', 1 ),
),
);
}
return $formatted_args;
}
/**
* Search Elasticsearch for related content
*
* @param int $post_id Post ID
* @param int $post_return Number of posts to return
* @since 4.1.0
* @return WP_Query
*/
public function get_related_query( $post_id, $post_return = 5 ) {
$args = array(
'more_like' => $post_id,
'posts_per_page' => $post_return,
'ep_integrate' => true,
'ignore_sticky_posts' => true,
);
/**
* Filter WP Query related post arguments
*
* @hook ep_find_related_args
* @param {array} $args WP Query arguments
* @since 2.1
* @return {array} New arguments
*/
return new WP_Query( apply_filters( 'ep_find_related_args', $args ) );
}
/**
* Search Elasticsearch for related content
*
* @param int $post_id Post ID
* @param int $post_return Number of posts to return
*
* @since 2.1
* @uses get_related_query
*
* @return array|bool
*/
public function find_related( $post_id, $post_return = 5 ) {
$query = $this->get_related_query( $post_id, $post_return );
if ( ! $query->have_posts() ) {
return false;
}
return $query->posts;
}
/**
* Setup all feature filters
*
* @since 2.1
*/
public function setup() {
add_action( 'widgets_init', [ $this, 'register_widget' ] );
add_filter( 'widget_types_to_hide_from_legacy_widget_block', [ $this, 'hide_legacy_widget' ] );
add_filter( 'ep_formatted_args', [ $this, 'formatted_args' ], 10, 2 );
add_action( 'init', [ $this, 'register_block' ] );
add_action( 'rest_api_init', [ $this, 'setup_endpoint' ] );
}
/**
* Setup REST endpoints
*
* @since 3.2
*/
public function setup_endpoint() {
$controller = new REST\RelatedPosts();
$controller->register_routes();
}
/**
* Register gutenberg block
*
* @since 3.2
*/
public function register_block() {
/**
* Registering it here so translation works
*
* @see https://core.trac.wordpress.org/ticket/54797#comment:20
*/
wp_register_script(
'ep-related-posts-block-script',
EP_URL . 'dist/js/related-posts-block-script.js',
Utils\get_asset_info( 'related-posts-block-script.js', 'dependencies' ),
Utils\get_asset_info( 'related-posts-block-script.js', 'version' ),
true
);
wp_set_script_translations( 'ep-related-posts-block-script', 'elasticpress' );
register_block_type_from_metadata(
EP_PATH . 'assets/js/blocks/related-posts',
[
'render_callback' => [ $this, 'render_block' ],
]
);
}
/**
* Render Gutenberg block
*
* @param array $attributes Block attributes
* @since 3.2
* @return string
*/
public function render_block( $attributes ) {
$posts = $this->find_related( get_the_ID(), $attributes['number'] );
if ( empty( $posts ) ) {
return '';
}
$class = 'wp-block-elasticpress-related-posts';
if ( ! empty( $attributes['align'] ) ) {
$class .= ' align' . $attributes['align'];
}
ob_start();
$wrapper_attributes = get_block_wrapper_attributes( [ 'class' => $class ] );
?>
<section <?php echo wp_kses_data( $wrapper_attributes ); ?>">
<ul>
<?php foreach ( $posts as $related_post ) : ?>
<li>
<a href="<?php echo esc_url( get_permalink( $related_post->ID ) ); ?>">
<?php echo wp_kses( get_the_title( $related_post->ID ), 'ep-html' ); ?>
</a>
</li>
<?php endforeach; ?>
</ul>
</section>
<?php
$block_content = ob_get_clean();
return $block_content;
}
/**
* Register related posts widget
*
* @since 2.2
*/
public function register_widget() {
register_widget( __NAMESPACE__ . '\Widget' );
}
/**
* Hide the legacy widget.
*
* Hides the legacy widget in favor of the Block when the block editor
* is in use and the legacy widget has not been used.
*
* @since 4.3
* @param array $widgets An array of excluded widget-type IDs.
* @return array array of excluded widget-type IDs to hide.
*/
public function hide_legacy_widget( $widgets ) {
$widgets[] = 'ep-related-posts';
return $widgets;
}
/**
* Output feature box long
*
* @since 2.1
*/
public function output_feature_box_long() {
?>
<p><?php echo wp_kses_post( __( 'Output related content using our Widget or directly in your theme using our <a href="https://www.elasticpress.io/documentation/article/related-posts-api/">API functions.</a>', 'elasticpress' ) ); ?></p>
<?php
}
}