Structured data in Divi theme

Structured data in Divi theme.php

<?php
add_action( 'wp_enqueue_scripts', 'ahmedkaludi_enqueue_styles' );
function ahmedkaludi_enqueue_styles() {
    wp_enqueue_style( 'parent-style', get_template_directory_uri() . '/style.css' );

}

// Display Tag code
function ahmedkaludi_structured_data_keyword() {
    if ( is_single() ) {
        $tags   = '"keywords" : [' . strip_tags(get_the_tag_list('"','", "','"')) . ']'; 
    } else { }
    echo $tags;
}


function ahmedkaludi_structured_data_output() { 
    if ( is_single() ) { 
        $article_author_name    =   get_the_author_meta( 'nickname', $author_id );
        $article_published_date =   get_the_time('c');
        $thumb_id = get_post_thumbnail_id();
        $thumb_url = wp_get_attachment_image_src($thumb_id,'large', true);


?>

        <script type="application/ld+json">
            {
              "@context": "http://schema.org",
              "@type": "Article",
              "headline": "<?php the_title(); ?>",
                  "image": {
                   "@type": "ImageObject",
                   "url": "<?php echo $thumb_url[0]; ?>",
                   "width": 1024,
                   "height": 1024
                  },
                <?php
                    if(function_exists('ahmedkaludi_structured_data_keyword'))
                    {
                        ahmedkaludi_structured_data_keyword();
                    };
                ?>,
                "datePublished": "<?php echo $article_published_date ?>",
                "dateModified": "<?php echo $article_published_date ?>",
                "articleSection": "<?php $categories = get_the_category(); foreach($categories as $category) { $cat_name = $category->name;  echo  $cat_name ; } ?>",
                "publisher":{
                    "@type": "Organization",
                    "name": "<?php echo $article_author_name ?>",
                    "logo": {
                        "@type": "ImageObject",
                        "url": "http://ahmedkaludi.com/logo.jpg",
                        "width": 600,
                        "height": 60
                    }
                },
               "author": {
                "@type": "Person",
                "name": "<?php echo $article_author_name ?>"
               },
                "articleBody": "<?php $excerpt = strip_tags(get_the_excerpt()); echo $excerpt; ?>",
              "mainEntityOfPage": "True"
            }
        </script> 
    <?php }
} 

add_action('wp_footer','ahmedkaludi_structured_data_output'); 


?>