Dear Val,
Thanks for your reply and I have good news for you.
We get it work but by debugging your plugin code and add a new short code [wcj_order_custom_meta_field] with this handling function as wcj_order_custom_meta_field.
function wcj_order_custom_meta_field( $atts ) {
if ( '' == $atts['field_id'] ) return '';
$field_value = $this->the_order->$atts['field_id'];
return ( isset( $field_value ) ) ? $field_value : '';
}
when we make the same test as you mention in your post (<p>Custom checkout field: [wcj_order_checkout_field field_id=”billing_wcj_checkout_field_1″]</p>) but we use the new short code as (<p>Custom checkout field: [wcj_order_custom_meta_field field_id=”field_id”]</p>), it works great and return the value that we need.
Here is the output as Custom checkout field: 123456789
Please, include this new option in your new version, so, it will be helpful to anyone that need this feature.
Thanks a lot for your time and efforts.