Every custom field can be set as a filters’ source data. However, these fields must be first registered – this process is not done automatically. Our integrations with third-party plugins, such as Advanced Custom Fields, are the exception. In this case, custom fields will be immediately selectable as a data source.
To make any custom field selectable from the Data source dropdown, you need to register them with this PHP snippet:
add_filter(
'fibofilters/filters/custom_sources/custom_fields',
function ( $custom_fields ) {
$custom_fields[] = [
'field_slug' => 'size', // meta_key
'label' => 'My custom field: Size',
'label_front' => 'Size',
];
return $custom_fields;
}
);
In the example above, a field is registered, whose meta_key in the postmeta table is size.
After adding this snippet, a new position “My custom fields: Size” should be selectable from the Data source dropdown:
