Page template option not showing after update to 4.7 - php

Question

I've used this plugin for adding specific templates for page.
class PageTemplater {
protected $plugin_slug;
private static $instance;
protected $templates;
public static function get_instance() {
if( null == self::$instance ) {
self::$instance = new PageTemplater();
}
return self::$instance;
}
private function __construct() {
$this->templates = array();
add_filter('page_attributes_dropdown_pages_args', array($this, 'register_project_templates'));
// add_filter('wp_insert_post_data', array($this, 'register_project_templates'));
add_filter('template_include', array($this, 'view_project_template'));
$this->templates = array(
'page-json.php' => 'JSON list',
);
}
public function register_project_templates( $atts ) {
// Create the key used for the themes cache
$cache_key = 'page_templates-' . md5( get_theme_root_uri() . '/' . get_stylesheet() );
// Retrieve the cache list.
// If it doesn't exist, or it's empty prepare an array
$templates = wp_get_theme()->get_page_templates();
if ( empty( $templates ) ) {
$templates = array();
}
// New cache, therefore remove the old one
wp_cache_delete( $cache_key , 'themes');
// Now add our template to the list of templates by merging our templates
// with the existing templates array from the cache.
$templates = array_merge( $templates, $this->templates );
// Add the modified cache to allow WordPress to pick it up for listing
// available templates
wp_cache_add( $cache_key, $templates, 'themes', 1800 );
return $atts;
}
/**
* Checks if the template is assigned to the page
*/
public function view_project_template( $template ) {
global $post;
if (!isset($this->templates[get_post_meta( $post->ID, '_wp_page_template', true)])) {
}
$file = plugin_dir_path(__FILE__) . get_post_meta($post->ID, '_wp_page_template', true);
// Just to be safe, we check if the file exists first
if (file_exists($file)) {
return $file;
} else {
echo $file;
}
return $template;
}
}
add_action( 'plugins_loaded', array( 'PageTemplater', 'get_instance' ) );
But when I've have updated a WordPress to 4.7 page template options had stopped to show. Maybe I use some deprecated functions?
Please help.

Answer 1

Fixed code:
// Add a filter to the attributes metabox to inject template into the cache.
if ( version_compare( floatval( get_bloginfo( 'version' ) ), '4.7', '<' ) ) {
// 4.6 and older
add_filter(
'page_attributes_dropdown_pages_args',
array( $this, 'register_project_templates' )
);
} else {
// Add a filter to the wp 4.7 version attributes metabox
add_filter(
'theme_page_templates', array( $this, 'add_new_template' )
);
}
/**
* Adds our template to the page dropdown for v4.7+
*
*/
public function add_new_template( $posts_templates ) {
$posts_templates = array_merge( $posts_templates, $this->templates );
return $posts_templates;
}
source: http://www.wpexplorer.com/wordpress-page-templates-plugin/