Defer javascript for for page speed

<?php

/*
Plugin Name: Defer parsing Javascript Firoze
Plugin URI:
Description: Just a defer parsing javascript plugin for WordPress site.
Author: Firoze
Version: 1.0.0
Author URI:
*/


/*-----------------------------------------------------
 *Latest Jquery For WP defer parsing javascript
 *------------------------------------------------------*/
function defer_parsing_javascript() {
	wp_enqueue_script( 'jquery' );
}
add_action( 'init', 'defer_parsing_javascript' );



/*-----------------------------------------------------
 * Some predefine Set-up for WP defer parsing javascript
 *-----------------------------------------------------*/
define('WP_defer_PlUGIN', WP_PLUGIN_URL . '/' . plugin_basename( dirname(__FILE__) ) . '/' );



/*------------------------------------------------------------
 * Main Jquery and Style for WP defer parsing javascript
 *------------------------------------------------------------*/
function wp_defer_main_jquery() {

	wp_enqueue_script( 'wp-defer-parsing', WP_defer_PlUGIN.'js/defer.js', array('jquery'), 1.0, false);

}
add_action( 'init', 'wp_defer_main_jquery' );




// Defer Javascripts
// Defer jQuery Parsing using the HTML5 defer property
if (!(is_admin() )) {
    function defer_parsing_of_js ( $url ) {
        if ( FALSE === strpos( $url, '.js' ) ) return $url;
        if ( strpos( $url, 'jquery.js' ) ) return $url;
        // return "$url' defer ";
        return "$url' defer onload='";
    }
    add_filter( 'clean_url', 'defer_parsing_of_js', 11, 1 );
}


// Move all JS from header to footer
if(!is_admin()) {
    remove_action('wp_head', 'wp_print_scripts');
    remove_action('wp_head', 'wp_print_head_scripts', 9);
    remove_action('wp_head', 'wp_enqueue_scripts', 1);
    add_action('wp_footer', 'wp_print_scripts', 5);
    add_action('wp_footer', 'wp_enqueue_scripts', 5);
    add_action('wp_footer', 'wp_print_head_scripts', 5);
}

// Defer JS for Contact Form 7

! defined( 'ABSPATH' ) and exit;

if ( ! function_exists( 'add_defer_to_cf7' ) )
{
function add_defer_to_cf7( $url )
{
if ( // comment the following line out add 'defer' to all scripts
// FALSE === strpos( $url, 'contact-form-7' ) or
FALSE === strpos( $url, '.js' )
)
{ // not our file
return $url;
}
// Must be a ', not "!
return "$url' defer='defer";
}
add_filter( 'clean_url', 'add_defer_to_cf7', 11, 1 );
}


// Remove query string from static files
function ewp_remove_scriptP( $src ){
	return remove_query_arg( 'ver', $src );
}
add_filter( 'script_loader_src', 'ewp_remove_scriptP', 15, 1 );
add_filter( 'style_loader_src', 'ewp_remove_scriptP', 15, 1 );



/*---------------------------------------------------
 * Add script in footer for WP  defer parsing javascript
 *---------------------------------------------------*/
function wp_def_active_foot(){
?>

<?php
}
add_action('wp_footer', 'wp_def_active_foot');


/*---------------------------------------------------
 * Add script in header for WP  defer parsing javascript
 *---------------------------------------------------*/
function wp_def_active_hed(){
?>
<script type="text/javascript">
function downloadJSAtOnload() {
var element = document.createElement("script");

element.src = "www.ideal-pro.com/Avada/wp-content/plugins/deferparsingjavascript/js/defer.js"; // defer.js

//element.src = "http://localhost/homelandwp/wp-content/plugins/deferparsingjavascript/js/defer.js"; // defer.js

document.body.appendChild(element);
}
if (window.addEventListener)
window.addEventListener("load", downloadJSAtOnload, false);
else if (window.attachEvent)
window.attachEvent("onload", downloadJSAtOnload);
else window.onload = downloadJSAtOnload;
</script>
<?php
}
add_action('wp_head', 'wp_def_active_hed');