How to use the get_children() function in WordPress

WordPress is a large and adaptable platform, with one of its most notable features being the ability to organise information hierarchically. Understanding parent-child relationships can be useful when working with pages, posts, or custom post kinds. get_children() is a useful method that allows you to delve deep into these relationships.

In today’s post, we’ll demystify the get_children() function and explore some practical use cases.

What is the get_children() Function?

The get_children() function in WordPress retrieves the child posts of a specific post. It’s especially useful when you’re dealing with hierarchical post types, like pages.

get_children( $args );

Here, $args is an array of arguments to define which children you want to retrieve.

Basic Use of get_children()

If you wanted to get the child pages of a parent page with the ID of 10, you could do:

$child_pages = get_children( array( 'post_parent' => 10 ) );
foreach ( $child_pages as $child ) {
    echo $child->post_title . '<br>';

Real-World Use Cases

1. Displaying Child Pages on a Parent Page

Imagine you’re building a website with a services section. Each service has its dedicated page and is a child of the main “Services” page. You want to list these services on the main page.

$child_pages = get_children( array( 'post_parent' => get_the_ID() ) );

if( !empty( $child_pages ) ) {
    echo '<ul>';
    foreach ( $child_pages as $child ) {
        echo '<li><a href="' . get_permalink( $child->ID ) . '">' . $child->post_title . '</a></li>';
    echo '</ul>';
} else {
    echo 'No child pages found.';

2. Retrieving All Attachments for a Post

Let’s say you want to fetch all image attachments for a post, to create a gallery:

$attachments = get_children( array(
    'post_parent'    => get_the_ID(),
    'post_type'      => 'attachment',
    'post_mime_type' => 'image',
    'orderby'        => 'menu_order'
) );

if ( $attachments ) {
    echo '<div class="gallery">';
    foreach ( $attachments as $attachment ) {
        echo wp_get_attachment_image( $attachment->ID, 'medium' );
    echo '</div>';

3. Creating a Dropdown of Child Pages

You might want a dropdown menu on a parent page that allows users to select and visit any child page.

$child_pages = get_children( array( 'post_parent' => get_the_ID() ) );

if( !empty( $child_pages ) ) {
    echo '<select onchange="location = this.value;">';
    echo '<option>Select a child page</option>';
    foreach ( $child_pages as $child ) {
        echo '<option value="' . get_permalink( $child->ID ) . '">' . $child->post_title . '</option>';
    echo '</select>';

Wrapping it up!

The get_children() function is incredibly versatile and powerful. As we’ve seen, it’s not just about retrieving child pages. From creating galleries using attachments to dynamically listing child pages, the potential applications are endless.

Keep this function in mind the next time you’re working on a WordPress project. It might just be the answer you’re looking for!