Trouble with parent and child conditional tag to show content

Question

I am trying to conditionally change a link based on what page a user is on, but I am having trouble finding the correct code to perform the action.

Here is what I want to do (In English to explain the code)

If a user is not logged-in and on a page that is either keyword or a child of keyword (for example, domain.net/keyword/pricing or domain.net/keyword/about or simply domain.net/keyword)

Then Show X

If user is not logged in and on any other page besides those mentioned above

Then Show Y

If user is logged in

Then Don't do anything

I've tried multiple conditionals and read the wordpress codex, but can't figure this one out. I am novice php user, so I wouldn't be surprised if the answer was quite simple.

I appreciate the help in advance!

Answer 1

If it is about child post types* or taxonomies**:

// page/post/cpt parent check:
$post_object = get_queried_object();
// check if the page has a parent
if ( $post_object->post_parent )
    // do stuff

// cat/tax parent check:
$taxonomy_object = get_the_category( get_query_var('cat') );
// check if the cat/tag/tax has a parent:
if ( $taxonomy_object->parent )
    // do stuff

It could be that you have to check the if against 0 !== $post_/taxonomy_object, but it should work close to shown above.

---

*) Post types are the built in ones like post and page, or custom ones like custom post types.

**) Taxonomies are the built in ones like category (hierarchical), tags (non-hierarchical), post_format, etc, or your custom ones like custom taxonomies.

Answer 2

I'm assuming you are referring to pages and child pages. If so, you can use this in your template within the loop:

$page_title = "Foo";
global $post;
$parent = $post->post_parent;

if(is_page($title))
    echo "bar";
if($parent){
    $parent = get_post($parent);
    if($parent->post_title == $title)
        echo "bar";
}
if(is_user_logged_in())
    echo "Foo Bar";