Enqueue Scripts / Styles when shortcode is present

I found an other way that works well for me:

• When initializing the plugin, do not enqueue your scripts and styles, but register them with wp_register_style and wp_register_script.

• Next you can load the script/style on demand. For example when you render a shortcode with wp_enqueue_style("your_style") and wp_enqueue_script("your_script").

Here is an example plugin using this method that lets you use get_avatar in a shortcode. The stylesheet is only enqueued when the shortcode is present.

Usage (id defaults to current user):

[get_avatar id="" size="32" default="mystery" alt="Profile Photo" class="round"]

function wpse_165754_avatar_shortcode_wp_enqueue_scripts() {
    wp_register_style( 'get-avatar-style', plugins_url( '/css/style.css', __FILE__ ), array(), '1.0.0', 'all' );
}

add_action( 'wp_enqueue_scripts', 'wpse_165754_avatar_shortcode_wp_enqueue_scripts' );
if ( function_exists( 'get_avatar' ) ) {
    function wpse_165754_user_avatar_shortcode( $attributes ) {

        global $current_user;
        get_currentuserinfo();

        extract( shortcode_atts(
                     array(
                         "id"      => $current_user->ID,
                         "size"    => 32,
                         "default" => 'mystery',
                         "alt"     => '',
                         "class"   => '',
                     ), $attributes, 'get_avatar' ) );
        
        $get_avatar = get_avatar( $id, $size, $default, $alt );

        wp_enqueue_style( 'get-avatar-style' );

        return '<span class="get_avatar ' . $class . '">' . $get_avatar . '</span>';
    }

    add_shortcode( 'get_avatar', wpse_165754_user_avatar_shortcode' );
}