WordPress SJON-LD Structured Data (Rich Snippets)

if (is_single()) {
	$sd_title		= esc_html(get_the_title());
	$sd_headline		= substr(wp_strip_all_tags(get_the_excerpt()),0,107) . '...';
	$sd_image		= get_the_post_thumbnail_url();
	$sd_permalink		= esc_url(get_permalink());
	$sd_published		= get_the_date('c');
	$sd_modified		= get_the_modified_date('c');
	$sd_author		= esc_html(get_the_author());
	$sd_organization	= get_bloginfo('name');
	$sd_modified		= get_the_modified_date('c');

	echo '
		<script type="application/ld+json">
		{
		  "@context": "http://schema.org",
		  "@type": "Article",
		  "mainEntityOfPage": {
			"@type": "WebPage",
			"@id": "' . $sd_permalink .'"
		  },
		  "headline": "' . $sd_headline . '",
		  "image": [
			"' . $sd_image . '"
		   ],
		  "datePublished": "' . $sd_published . '",
		  "dateModified": "' . $sd_modified . '",
		  "author": {
			"@type": "Person",
			"name": "' . $sd_author . '"
		  },
		   "publisher": {
			"@type": "Organization",
			"name": "' . $sd_organization . '",
			"logo": {
			  "@type": "ImageObject",
			  "url": "your-url-to-the-logo-image"
			}
		  },
		  "description": "' . $sd_title . '"
		}
		</script>
		';
	}