Send autologin link on registration email

Hi,

Been looking throughout the code and implemented a solution that seems to work for my personal needs.

Here’s the code:

//generate autologin links for registered users
function generateRandomString($length = 60) {
    $characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
    $charactersLength = strlen($characters);
    $randomString = '';
    for ($i = 0; $i < $length; $i++) {
        $randomString .= $characters[rand(0, $charactersLength - 1)];
    }
    return $randomString;
}

add_action( 'user_register', 'myplugin_registration_save', 10, 1 );
function myplugin_registration_save( $user_id , $length ) {
	global $meta_key;
	global $my_array;
	$my_array['ID'] = $user_id;

	if ( isset(  $_POST['user_login'] ) ) {
		$my_array['user_login'] =  $_POST['user_login'];
	} else {
		$user_info = get_userdata( $user_id );
		$my_array['user_login'] = $user_info->user_login;
	}

	$meta_key = "pkg_autologin_code";
	$my_array['mkey'] = $meta_key;
	$timestampz=time();
	$tokenparta = generateRandomString();
	$key = $timestampz*3 . $tokenparta;
	$my_array['kkey'] = $key;

	update_user_meta( $user_id, $meta_key, $key,  $my_array['mkey'], $my_array['kkey']);
}

add_filter( 'wp_mail', 'send_auto_login_link' );
function send_auto_login_link( $atts ) {
	if ( isset ( $atts ['subject'] ) && $atts['subject'] = 'Your username and password' ) {
		if ( isset( $atts['message'] ) ) {
			global $my_array;
			$qstr = '?autologin_code=' . $my_array['kkey'];
			$old = '/wp-login.php';
			$new = '/' . $qstr;
			$atts['message'] = str_replace( $old, $new, $atts['message'] );
		}
	}
	return $atts;
}

I’ve used the shared code for auto generate the autologin link on user registration, and created an override for the user registration email, that gets an array of info, like the user_id, and key to replace the original message with user info and autologin link.

Let me know if it works for you too.
Thanks!