Removing Unnecessary CSS Files

Question

I am in the process of optimizing my Drupal site by removing unnecessary css files.

Running an audit I have found that /misc/ui/jquery.ui.core.css, /misc/ui/jquery.ui.theme.css and /misc/ui/jquery.ui.slider.css are relatively large but are never called.

I have tried removing them in my template.php file with the following but they still remain. How can I unset them?

unset($css[DRUPAL_ROOT.'/misc/ui/jquery.ui.slider.css']);
unset($css[DRUPAL_ROOT.'/misc/ui/jquery.ui.core.css']);
unset($css[DRUPAL_ROOT.'/misc/ui/jquery.ui.theme.css']);

Answer 1

You can use hook_ccs_alter

function yourmodule_css_alter(&$css) {

  unset($css['misc/ui/jquery.ui.core.css']);
}

Answer 2

An alternative way in Drupal 7 using YOUR_THEME_css_alter() is

    function YOUR_THEME_css_alter(&$css) {
    // Remove Drupal core css 
        $exclude = array( //confirm path
            'misc/ui/jquery.ui.slider.css' => FALSE,
            'misc/ui/jquery.ui.core.css' => FALSE,
            'misc/ui/jquery.ui.theme.css' => FALSE,
            // Also you can remove contrib module CSS 
            drupal_get_path('module', 'views') . '/css/views.css' => FALSE,);
        $css = array_diff_key($css, $exclude);
    }