Enqueue scripts inside a class

Question

I have written a small class that will handle enqueues in my theme :

<?php

class Header {

    public function init_hooks()
    {
        add_action('wp_print_scripts', array(__CLASS__,'include_all_files'));
    }

    public function include_css_files()
    {
        wp_register_script('style.css', get_bloginfo('stylesheet_url'));
        wp_enqueue_script('style.css');
    }

    public function include_js_files()
    {
        wp_register_script('jquery-min', "http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js");
        wp_enqueue_script('jquery-min');        
    }

    public function include_all_files()
    {
        $this->include_css_files();
        $this->include_js_files();
    }

}

?>

I call it right before closing the head tag, like :

$header = new Header();
$header->init_hooks(); 

But it does not work. There is no error, but no script is added. Any ideas ?

Answer 1

You mean you call your class right before closing HTML tag? It is too late to enqueue scripts then.

Don't hook into wp_print_scripts to enqueue your scripts and styles. I just learned this today from Rarst.

So change your init_hooks function to something like following:

public function init_hooks()
{
    add_action('wp_enqueue_scripts', array(__CLASS__,'include_all_files'));
}

Also you are using wp_register_script and wp_enqueue_script functions to enqueue your styles, Wordpress has separate functions to enqueue your styles wp_register_style and wp_enqueue_style. Your include_css_files should look like:

public function include_css_files()
{
    // NOTE: you don't really have to use the filename as style slug.
    wp_register_style('my_style', get_bloginfo('stylesheet_url'));
    wp_enqueue_style('my_style');
}

Now about instantiating your class and calling init_hooks. You can either place it directly inside your functions.php, or you can use the init action to instantiate your class.