PHP Notice - Custom Function

Question

I am using this code:

function the_alt_title($title= '') {
    $page = get_page_by_title($title);
    if ($p = get_post_meta($page->ID, "_x_entry_alternate_index_title", true)) {
        $title = $p;
    }

    return $title;
}
add_filter('the_title', 'the_alt_title', 10, 1);

In debug.log i get

PHP Notice:  Trying to get property of non-object in /var/www/html/wp-content/themes/my-child/functions.php on this line:

 if ($p = get_post_meta($page->ID, "_x_entry_alternate_index_title", true)) {

How could I fix this?

Answer 1

$page = get_page_by_title($title) - this line is failing somewhere, so you should do a check on this to make sure it exists.

Like so:

function the_alt_title($title= '') {
    $page = get_page_by_title($title);
    if (!$page) {
        return $title;
    }

    if ($p = get_post_meta($page->ID, "_x_entry_alternate_index_title", true)) {
        $title = $p;
    }

    return $title;
}
add_filter('the_title', 'the_alt_title', 10, 1);

Answer 2

Have to globalize page to access it.

    function the_alt_title($title= '') {
    global $page; //here
    $page = get_page_by_title($title);
    if ($p = get_post_meta($page->ID, "_x_entry_alternate_index_title", true)) {
        $title = $p;
    }

    return $title;
}
add_filter('the_title', 'the_alt_title', 10, 1);