Add new custom fields via child theme in Metabox

All of our themes use Metabox plugin to add custom fields. Sometimes you may need to add additional fields to an existing metabox. This can be done with a simple function added to your child theme. Below is an example showing additional fields to obituary metabox of our Obsequy theme. All of our themes comes bundled with a basic child theme.

To add additional fields to the obituary_meta_box metabox created with the Metabox plugin via a child theme, follow these steps:

Steps to Add Fields via Child Theme:

1. Hook into rwmb_meta_boxes
   The Metabox plugin uses the rwmb_meta_boxes filter to register custom metaboxes. You can modify it in your child theme by adding new fields.

2. Locate the Existing Metabox Key
   Ensure the obituary_meta_box is the correct metabox ID registered in the parent theme/plugin.

3. Add Additional Fields in Your Child Theme’s functions.php
   Use the following code in your child theme’s functions.php:

function child_theme_add_obituary_meta_fields( $meta_boxes ) {
    foreach ( $meta_boxes as &$meta_box ) {
        if ( isset( $meta_box['id'] ) && $meta_box['id'] === 'obituary_meta_box' ) {
            $meta_box['fields'][] = [
                'name'  => 'Cause of Death',
                'id'    => 'cause_of_death',
                'type'  => 'text',
                'desc'  => 'Enter the cause of death',
            ];

            $meta_box['fields'][] = [
                'name'  => 'Burial Location',
                'id'    => 'burial_location',
                'type'  => 'text',
                'desc'  => 'Enter the burial location',
            ];
        }
    }
    return $meta_boxes;
}
add_filter( 'rwmb_meta_boxes', 'child_theme_add_obituary_meta_fields', 20 );

Modify the type accordingly based on your needs. See all the available field types with documentation here