如何在Wordpress中调用儿童主题

Question

I am currently trying to edit someone elses code and they have written the following;

?>

<?php get_header(); ?>
   <?php include(TEMPLATEPATH.'/navigation.php'); ?>   
   <div class="main">
<?php
if(is_subpage()){  /// THIS LINE RETURNS ERROR
   $parent_title = get_the_title($post->post_parent);
   echo '<h2>Distributor Support Site</h2>';
}
?>

However, this code returns the following error for is_subpage

( ! ) Fatal error: Call to undefined function is_subpage() in aaaaaaaaa.php on line 53 (is_sub)

I believe someome was trying to check if the parent theme has a child theme? Does anyone know the proper way to acheive this?

Thanks in advance!

Answer 1

Wordpress does not have a core function, that checks if you are currently on a sub/childpage - So at some point, a function must have been lost -

It looks very much like the function that I use myself, taken from github : Here

If at some point, this github page is removed - I will paste the function here as well.

With this function - everything should work again.

---

Function :

/**
* Is SubPage?
*
* Checks if the current page is a sub-page and returns true or false.
*
* @param $page mixed optional ( post_name or ID ) to check against.
* @param $single boolean optional - default true to check against all parents, false to check against immediate parent.
* @return boolean
*/

function is_subpage( $page = null, $all = true ) {
  global $post;
    // is this even a page?
    if ( ! is_page() )
        return false;
    // does it have a parent?
    if ( ! isset( $post->post_parent ) OR $post->post_parent <= 0 )
        return false;
    // is there something to check against?
    if ( ! isset( $page ) ) {
        // yup this is a sub-page
        return true;
    } else {
        // if $page is an integer then its a simple check
        if ( is_int( $page ) ) {
            // check
            if ( $post->post_parent == $page )
                return true;
        } else if ( is_string( $page ) ) {
            // get ancestors
            $parents = get_ancestors( $post->ID, 'page' );
            // does it have ancestors?
            if ( empty( $parents ) )
                return false;
            if ( $all == true ) { // check against all parents
                // loop through ancestors
                foreach ( $parents as $parent ) {
                    $parent = get_post( $parent );
                    if ( is_page() && $parent->post_name == $page) {
                        return true;
                    }
                }
            } else { // check against immediate parent
                // get the first ancestor
                $parent = get_post( $parents[0] );
                // compare the post_name
                if ( $parent->post_name == $page )
                    return true;
            }
        }
        return false;
    }
}