DevTeam-Admin
3/26/2020 - 11:05 PM

Preload main JS file

This will add a preload tag to the head, so the main javascript file in the footer is downloaded asynchronously, and executed when it's called. You can add additional scripts to this function by adjusting the if statement with the handles.

function.php
content_copyfile_download
/** 
 * Preload main JS file
 */
function rs_preload_scripts() {
    global $wp_scripts;
    foreach($wp_scripts->queue as $handle) {
        if( $handle === 'theme_js' ) { // change this to the handle of your script
            $script = $wp_scripts->registered[$handle];
            $source = $script->src . ($script->ver ? "?ver={$script->ver}" : "");
            echo "<link rel='preload' href='{$source}' as='script'/>\n";
        }
    }
}
add_action('wp_head', 'rs_preload_scripts');