wp_enqueue_scripts in a plugin's class

Question

I'm trying to enqueue jQuery UI in a plugin under a class method. I have this so far:

class AV_Slider {

function slider_load_js(){
        wp_register_script('jquery-ui-core', 'http://ajax.googleapis.com/ajax/libs/jqueryui/1.5.3/jquery-ui.min.js');
        wp_enqueue_script('jquery-ui-core', array('jquery') );
        wp_enqueue_script('av_slider_js', AV_SLIDER_BASE_URL . 'includes/js/av_slider.js', array( 'jquery' ));
}


function __construct(){
    $this->hooks();
}
function hooks(){
    add_action('wp_enqueue_scripts', 'slider_load_js');
}

And I get this error on the page:

Warning: call_user_func_array() expects parameter 1 to be a valid callback, function 'slider_load_js' not found or invalid function name

I'm not sure how __construct() works other than that it creates a new Simple XML object. I also tried adding the action add_action('wp_enqueue_scripts', 'slider_load_js'); after the function but this caused an error as well.

Any help?

Answer 1

First of all - I'm not sure why you are registering jquery-ui-core. WordPress has already registered jQuery UI scripts (see here). You should use the shipped jquery and jquery-ui scripts rather than registering your own.

As for the error - the second argument add_action (and apply_filter for that matter) is a callback. To have a class method as a callback, you need to specify the class. In your case, using $this:

add_action('wp_enqueue_scripts', array($this,'slider_load_js'));