Preserving the user line breaks in a custom text area in woocommerce - function

Question

I have managed to add a custom text area to the woocommerce product data where my client can add in a kit list that is output to the packing list for the shop floor but the line breaks don't save and the output is a flow of text making it less easy on the eye for the guys picking
This is what I have but where and how do I make it preserve the line breaks added in the admin suite to output on the packing slip:
//General Fields
add_action( 'woocommerce_product_options_general_product_data', 'woo_add_custom_general_fields',10,3
);
add_action( 'woocommerce_process_product_meta', 'woo_add_custom_general_fields_save',10,2 );
//variable data
add_action('woocommerce_product_after_variable_attributes', 'variation_settings_fields', 10, 3);
add_action('woocommerce_save_product_variation','save_variation_settings_fields',10, 2);
//data tab
add_action( 'woocommerce_product_data_panels', 'add_my_custom_product_data_fields',10,3 );
add_action( 'woocommerce_process_product_meta','woocommerce_process_product_meta_fields_save',10,2 );
function woo_add_custom_general_fields() {
global $woocommerce, $post;
// Textarea
woocommerce_wp_textarea_input(
array(
'id' => '_textarea[' . $post->ID . ']',
'label' => __( 'Kit List', 'woocommerce' ),
'placeholder' => '',
'description' => __( 'Enter the kit list here.', 'woocommerce' ),
'value' => get_post_meta( $post->ID, '_textarea', true ),
)
);
}
function woo_add_custom_general_fields_save( $post_id ){
// Textarea
$textarea = $_POST['_textarea'][ $post_id ];
if( ! empty( $textarea ) ) {
update_post_meta( $post_id, '_textarea', esc_attr( $textarea ) );
}
}
function variation_settings_fields($loop, $variation_data, $variation){
// Textarea
woocommerce_wp_textarea_input(
array(
'id' => '_textarea[' . $variation->ID . ']',
'label' => __( 'Kit List', 'woocommerce' ),
'placeholder' => '',
'description' => __( 'Enter the kit list here.', 'woocommerce' ),
'value' => get_post_meta( $variation->ID, '_textarea', true ),
)
);
}
function save_variation_settings_fields($post_id){
// Textarea
$textarea = $_POST['_textarea'][ $post_id ];
if( ! empty( $textarea ) ) {
update_post_meta( $post_id, '_textarea', esc_attr( $textarea ) );
}
}
add_action( 'wpo_wcpdf_after_item_meta', 'wpo_wcpdf_product_custom_field', 10, 3 );
function wpo_wcpdf_product_custom_field ( $template_type, $item, $order ) {
if ( $template_type == 'packing-slip' ) {
// check if product exists first
if (empty($item['product'])) return;
// replace 'Location' with your custom field name!
$field_name = '_textarea';
$textarea = method_exists($item['product'], 'get_meta') ? $item['product']
->get_meta($field_name,true,'edit') : get_post_meta( $item['product']->id, $field_name, true );
if (!empty($textarea)) {
echo nl2br('Kit List: '.$textarea.'');
}
}
}

Answer 1

That trouble in function wc_clean - it used to get value and always use _sanitize_text_fields( $str, false ), so regardless of field type, woo removes trailing characters :( See trace below:
In may situation (Need additional field in address), I found it in form edit address.
#/wp-content/plugins/woocommerce/templates/myaccount/form-edit-address.php:38
woocommerce_form_field( $key, $field, wc_get_post_data_by_key( $key, $field['value'] ) );
where wc_get_post_data_by_key function return cleaned data by wc_clean
#/wp-content/plugins/woocommerce/includes/wc-core-functions.php:2005
return wc_clean( wp_unslash( wc_get_var( $_POST[ $key ], $default ) ) ); // #codingStandardsIgnoreLine
that use satinize text
#/wp-content/plugins/woocommerce/includes/wc-formatting-functions.php:392
return is_scalar( $var ) ? sanitize_text_field( $var ) : $var;
where not keep_newlines set (by default it is false):
#WordPress/wp-includes/formatting.php:5244
$filtered = _sanitize_text_fields( $str, false );
Thus, there are no line breaks in all data of any type received by the function wc_get_post_data_by_key()
#WordPress/wp-includes/formatting.php:5317
if ( ! $keep_newlines ) {
$filtered = preg_replace( '/[\r\n\t ]+/', ' ', $filtered );
}
Solution (?)
the solution is cardinal - leave line breaks for all text fields similar to sanitize_textarea_field ():
add_filter( 'sanitize_text_field', function ( $filtered, $str ) {
return _sanitize_text_fields( $str, true );
}
, 10, 2 );