How to remove CSS files if the page being rendered is a front page in a theme?

Question

I want to remove default Drupal CSS files if it is a front page in Drupal 7 theme.

Following is the code (got from http://www.grahamgilchrist.com/blog/25) that I am trying to put in the template.php for barktik1 theme. How do I check if rendering page is a front page or not? Only $css variable is passed as an argument to the theme_css_alter() function while for other process functions $variables is passed from which it is easy to determine if it is a front page or not.

function bartik1_css_alter(&$css) { 

//do something to check if it is a front page
if ($is_front){
    //make a list of module css to remove 
    $css_to_remove = array(); 
    $css_to_remove[] = drupal_get_path('module','system').'/system.base.css'; 
    $css_to_remove[] = drupal_get_path('module','system').'/system.menus.css'; 

    // now we can remove the contribs from the array 
    foreach ($css_to_remove as $index => $css_file) { 
      unset($css[$css_file]); 
    } 
    }
} 

Thanks!

Answer 1

The function you're looking for is drupal_is_front_page().

Answer 2

In both Drupal 7 and 8 you have hook_css_alter for altering CSS files before output on the page.

If you want to remove some default css file from your Drupal 7 home page you can go with:

function YOUR_THEME_css_alter(&$css) {
  if (drupal_is_front_page() == TRUE  )  {
    unset($css['/'.drupal_get_path('theme', 'YOUR_THEME').'/css/removeme.css'] );
  }
}