WordPress Parent/Child Page Filtering - php

Question

I want to create a form with two fields. The first field lists all pages and the second field lists all child pages (if they exist) of the chosen page from the first field. When the form is submitted the site redirects the user to the chosen page. How can I implement this form?

Answer 1

You're going to need to do an AJAX request to get the second drop down list.
There is a function built into WordPress which gets the pages and you can specify parent ID's and also to show only top level pages.
Heres an example of the code but you'll need to then implement it in a way that best suits your requirements
<?php
$top_level_pages = get_pages(array('parent'=> 0));
?>
<select>
<?php
foreach($top_level_pages as $top_level_page) {
echo '<option>'.$top_level_page['post_title'].'</option>';
}
?>
</select>
You will then need to determine what option the user has clicked and run an AJAX request to fill the second select.
The second select should look something like this:
<?php
$id = $_GET['page_id']; // get the id of the page from the first select
$child_pages = get_pages(array('child_of'=>$id));
?>
<select>
<?php
foreach($child_pages as $child_page) {
echo '<option>'.$child_page['post_title'].'</option>';
}
?>
</select>
Read more about the get_pages() function here: http://codex.wordpress.org/Function_Reference/get_pages