Filter out unwanted order item meta data from Woocommerce email notifications

Question

In the order email templates (for example email-order-items.php), WooCommerce uses the function wc_display_item_meta to display product details in

Answer 1

I kind of agreed with @pstidsen argument. So I was thinking about how to solve this without to re-add all the metadata, since it kind of disturbed me not to handle it in the same way as it was added before. I have additional filters to add css classes and so on to the metadata. So there would've been a need to take care of.

So here is my approach which gives you the opportunity to use it for emails, custom emails, pdf invoices or similar scenarios. I also uses a fallback to filter for our frontend or any situation we didn't consider. Please keep the order of if else in mind. I checked the admin filter the last, to make sure any other filter gets fired before. The situation for an email at example is: It's sent from the admin interface, so the admin filter is true but also is the email filter. Functionality for a different filter for admin emails is given as well.

/**
* This function filters all unwanted item metadata, if the specific filter are hooked in
* we also use a fallback filter, if none of the hooks are fired
*
* @params array() $metadata
*
*/
add_filter( 'woocommerce_order_item_get_formatted_meta_data', 'custom_filter_item_meta_data', 50, 1);
function custom_filter_item_meta_data( $metadata ){
    if ( empty( $metadata ) ) return $metadata;
    $filter_array = array();
    if ( apply_filters( 'custom_filter_item_meta_email', false ) ){
        // email filter goes here
        $filter_array = array( 'whatever','you', 'wanna', 'filter, 'for', 'email' );
    }elseif ( apply_filters( 'wrs_filter_item_meta_admin_email', false ) ){
        // admin email filter goes here
        // pass
    elseif ( apply_filters( 'custom_filter_item_meta_invoice', false ) ){
        // invoice filter goes here
        $filter_array = array( 'whatever','you', 'wanna', 'filter, 'for', 'invoices' );
    }elseif ( apply_filters( 'custom_filter_item_meta_admin', false ) ){
        // general admin filter goes here
        $filter_array = array( 'whatever','you', 'wanna', 'filter, 'for', 'admin_backend' );
    }else{
        // fallback filter
        $filter_array = array( 'whatever','you', 'wanna', 'filter, 'for', 'fallback' );
    }
    foreach ( $metadata as $key => $meta ){
        if ( in_array( $meta->key, $filter_array ) ){
            unset ( $metadata[ $key ] );
        }
    }
    return $metadata;
}

/**
* Is used to enable our item meta filter for our admin backend
* Hooked:
* @admin_init
*/
add_action( 'admin_init', 'custom_init_item_meta_filter_admin', 50, 1 );
function custom_init_item_meta_filter_admin(){
    add_filter( 'custom_filter_item_meta_admin', function(){ return true; });
}

/**
* Is used to enable our item meta filter for emails
* Hooked:
* @woocommerce_email_order_details
*/
add_action( 'woocommerce_email_order_details', 'custom_init_item_meta_filter_email' ), 10, 2);
function wrs_init_item_meta_filter_email( $order, $sent_to_admin ){
    if ( $sent_to_admin ){
        add_filter('wrs_filter_item_meta_admin_email', function(){ return true; } );
    }else{
        add_filter('wrs_filter_item_meta_email', function(){ return true; } );
    }
}

/**
* Is used to enable our item meta filter for invoices
* Hooked:
* @wpo_wcpdf_before_order_details
*/
add_filter( 'wpo_wcpdf_before_order_details', 'custom_init_item_meta_filter_invoice', 10, 1);
function custom_init_item_meta_filter_invoice(){
    add_filter( 'custom_filter_item_meta_invoice', function(){ return true; });
}

I din't test it in that "flattened" format. I used it within different classes of my oop coded plugin and edited it to post it here.