Wordpress: Hide the editor on defined pages

wordpress-hide-editor-on-pages.php

/**
 * Hide the main editor on specific pages
 */
define('EDITOR_HIDE_PAGE_TITLES', json_encode(array()));
define('EDITOR_HIDE_PAGE_TEMPLATES', json_encode(array('template-cars.php')));


/**
 * Hide the main editor on defined pages
 * 
 * You can choose between page titles or page templates. Just set them 
 * accordingly like this:
 * 
 * define('EDITOR_HIDE_PAGE_TITLES', json_encode(array('Home', 'Some post archive', 'Some Listing')));
 * define('EDITOR_HIDE_PAGE_TEMPLATES', json_encode(array('template-of-something.php', 'archive-customposttype.php')));
 * 
 * 
 * @global string $pagenow
 * @return void
 */
function atz_hide_editor() {
	global $pagenow;
    if(!('post.php' == $pagenow)){
		return;
	}
	
	// Get the Post ID.
	$post_id = filter_input(INPUT_GET, 'post') ? filter_input(INPUT_GET, 'post') : filter_input(INPUT_POST, 'post_ID');
	if(!isset($post_id)) {
		return;
	}

	// Hide the editor on the page titled 'Homepage'
	if(in_array(get_the_title($post_id), json_decode(EDITOR_HIDE_PAGE_TITLES))) {
		remove_post_type_support('page', 'editor');
	}

	// Hide the editor on a page with a specific page template
	$template_filename = get_post_meta($post_id, '_wp_page_template', true);

	if(in_array($template_filename, json_decode(EDITOR_HIDE_PAGE_TEMPLATES))) {
		remove_post_type_support('page', 'editor');
	}
}
add_action('admin_init', 'atz_hide_editor');