Plugin to show pagemap beneath certain page and next/previous page beneath certain page?

Question

I'm publishing a course online. The course is written on pages and I need some kind of navigation for the course.

For navigation I want:

• Previous/next page links
• A page index

I figure that all the book pages will be subpages (in several levels) to a starting page called "Book". It should be possible to navigate between these with previous/next page. It should also be possible to navigate by clicking on a link in the page index. I imagine that I would show this index either in the sidebar or on each page.

I imagine that the shortcodes could look something like

[previous_page pages_under="/Book" text="<< Previous page"]
[next_page pages_under="/Book" text="Next page >>"]
[pageindex pages_under="/Book" bullets="numbered" hierarchy="indent" current_page_in_pageindex="Make bold and remove link"]

Answer 1

This will get you the parent page ID:

$post->post_parent

..and this will get that parent page's children:

get_children($post->post_parent);

By default that will return an object. You can then play about with that object to your heart's content, including making a navigation of sorts.

Something like this to get started:

<ul>
    <li class="heading"><?php get_title($post->post_parent); ?></li>
    <?php

        $children = get_children($post->post_parent);

        foreach($children as $c) {
            echo '<li>'.get_title($c->ID).'</li>';
        };

    ?>
</ul>