[WordPress]http2_push.php

http2_push.php

<?php
add_action('template_redirect', function(){
    if ( headers_sent() ) {
        return;
    }

    do_action('wp_enqueue_scripts');

    foreach( array('style' => wp_styles(), 'script' => wp_scripts()) as $as => $wp_links ) {
        $link = '';
        foreach ( $wp_links->queue as $handle ) {
            if ( $wp_links->registered[$handle] && ! preg_match('/-ie8$/i',$handle) && 'html5' !== $handle ) {
                $wp_link = $wp_links->registered[$handle];
                $src = preg_replace('#^https?://[^/]+#', '', $wp_link->src);
                $ver = $wp_link->ver ? $wp_link->ver : $wp_links->default_version;
                $link .= !empty($link) ? ', ' : '';
                $link .= " <{$src}?ver={$ver}>; rel=preload; as={$as}";
                //header("Link: <{$src}?ver={$ver}>; rel=preload; as={$as}", false);
            }
        }
        if ( !empty($link) ) {
            header("Link:$link", false);
        }
    }

}, 0, 1);

I realized that $wp_links->queue doesn't have all dependencies.

To get all dependencies:

$queue = $wp_links->queue;
$wp_links->all_deps( $queue );
$to_do = $wp_links->to_do; // All list of items that should be loaded.