JSON sitemap generation for use with UnCSS (+ Sage theme)

extras.php

<?php

/**
 * Generate JSON sitemap for use with UnCSS
 */

function show_sitemap() {
	
	if (WP_ENV === 'development' && isset($_GET['show_sitemap'])) {
		
		$the_query = new \WP_Query(array('post_type' => 'any', 'posts_per_page' => '-1', 'post_status' => 'publish'));
		$urls = array();
		
		while($the_query->have_posts()) {
			
			$the_query->the_post();
			$urls[] = get_permalink();
		}
		
		// include category-template(s), one would actually suffice...
		$categories = get_categories();
		
		foreach($categories as $category) {
			
			$urls[] = home_url().get_category_link( $category->term_id );
		}
		
		$urls[] = get_search_link('liebe'); // some search-term to include search-template, should throw at least one result 
		$urls[] = home_url().'/somethingyouwillneverfind'; // generate 404-template page
		$urls[] = home_url(); // include home-url (no static page is used)
		
		die(json_encode($urls));
	}
}

add_action('template_redirect', __NAMESPACE__ . '\\show_sitemap');

?>