SNIP Comments Field

snip-comments-field.php

<?php
/*
Plugin Name: SNIP Comments Field
Description: Allows to integrate comments into Structured Data.
Author: Florian Simeth
Version: 0.1.0
Author URI: https://rich-snippets.io
Plugin URI: https://rich-snippets.io/comments-field-type/
*/

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

/**
 *
 * PHP Version check.
 *
 */
if ( version_compare( PHP_VERSION, '7.0', '<' ) ) {
	add_action( 'admin_notices', 'snip_comf_old_php_notice' );

	function snip_comf_old_php_notice() {

		printf(
			'<div class="notice error"><p>%s</p></div>',
			sprintf(
				__( 'Hey mate! Sorry for interrupting you. It seem\'s that you\'re using an old PHP version (your current version is %s). You should upgrade to at least 7.0 or higher in order to use the SNIP Field Type Example plugin. Thank you!', 'snip-comf' ),
				esc_html( PHP_VERSION )
			)
		);
	}

	# sorry. The plugin will not work with an old PHP version.
	return;
}


add_filter( 'wpbuddy/rich_snippets/fields/internal_subselect/values', 'snip_comf_subselects' );

/**
 * Adds new field to use in Global Snippets in the SNIP plugin.
 *
 * @param array $values
 *
 * @return array
 * @since 0.1.0
 *
 */
function snip_comf_subselects( $values ) {

	$values['http://schema.org/Comment'][] = [
		'id'     => 'snip_comf_comments',
		'label'  => esc_html_x( 'List of comments', 'subselect field', 'snip-comf' ),
		'method' => 'snip_comf_comments_callback',
	];

	return $values;
}


/**
 * Returns the value.
 *
 * @param                                     $val
 * @param \wpbuddy\rich_snippets\Rich_Snippet $rich_snippet
 * @param array                               $meta_info
 *
 * @return stdClass[]
 *
 * @since 0.1.0
 */
function snip_comf_comments_callback( $val, \wpbuddy\rich_snippets\Rich_Snippet $rich_snippet, array $meta_info ) {

	$comments = [];

	global $wp_query;

	if ( ! is_array( $wp_query->comments ) ) {
		return $comments;
	}

	/**
	 * @var WP_Comment $comment
	 */
	foreach ( $wp_query->comments as $comment ) {
		$c               = new stdClass();
		$c->{'@type'}    = 'Comment';
		$c->{'@context'} = 'http://schema.org';
		$c->dateCreated  = date_i18n( 'c', $comment->comment_date );
		$c->text         = esc_html( $comment->comment_content );

		$c->author               = new stdClass();
		$c->author->{'@type'}    = 'Person';
		$c->author->{'@context'} = 'http://schema.org';
		$c->author->name         = $comment->comment_author;

		$comments[] = $c;
	}

	return $comments;
}

This example shows you you can integrate an array of simple comments into Structured Data generated with SNIP - The Structured Data Plugin for WordPress.
Read the full how to here: https://rich-snippets.io/comments-field-type/