The reason this is not working is because you are trying to use undefined variables, they are declared outside the function and can therefor not be used without prefixing them with the global
keyword.
If you have error_reporting
enabled you would see warnings like this:
Notice: Undefined variable: current_user in
/… on line 11Notice: Undefined variable: author_id in
/… on line 11
You enable debugging by setting WP_DEBUG
to true
in your wp-config.php
file.
Adding the global
keyword would make the variables accessible from within the function:
function showSidebarWhenNeeded()
{
global $current_user;
global $author_id;
if ( $current_user->ID !== $author_id ) {
// ...
}
}
I would instead set the variables inside the function:
function showSidebarWhenNeeded($post_id)
{
$author_id = get_post_field ( 'post_author', $post_id );
$current_user = wp_get_current_user();
if ( $current_user->ID !== $author_id ) {
// ...
}
}