Enqueue scripts inside a class in a plugin

By the time your widget (or sidebar if this is hard-coded) loads you have already missed the wp_enqueue_scripts hook, which runs in the header and that means that you have missed the window for registering the script in the <head> at all, which you are trying to do– there is no fifth parameter that would load the script in the footer.

You can enqueue in wp_footer or any other hook that runs after wp_enqueue_scripts so long as you add the fifth parameter so that the script loads in the footer.

class MyPlugin
{
  public function __construct()
  {
    add_action('wp_footer', array($this, 'enqueueAssets'));
  }

  public function enqueueAssets()
  {
    wp_register_script('myplugin', plugins_url('myplugin.js', __FILE__), array('jquery'), '', true);
    wp_enqueue_script('myplugin');
  }

  // More methods
}

While the Codex does state that you should register on wp_enqueue_scripts, it also says:

As of Version 3.3, the function can be called mid-page (before the
wp_footer() template tag) or using the wp_head action hook. This will
place the script in the footer as if the $in_footer parameter was set
to true.

http://codex.wordpress.org/Function_Reference/wp_enqueue_script

Related Posts: