Show custom field value in cart in WooCommerce - php

Question

I'm using Wordpress together with WooCommerce for my shop.
I want to output the value of my custom field in my cart and in the email order confirmation.
I have created a custom field in my functions.php:
// Display Fields
add_action( 'woocommerce_product_options_general_product_data', 'woo_add_custom_general_fields' );
// Save Fields
add_action( 'woocommerce_process_product_meta', 'woo_add_custom_general_fields_save' );
function woo_add_custom_general_fields() {
global $woocommerce, $post;
echo '<div class="options_group">';
// Input
woocommerce_wp_text_input(
array(
'id' => '_gram',
'label' => __( 'somelabel', 'woocommerce' ),
'placeholder' => '',
'description' => __( 'sometext', 'woocommerce' ),
'type' => 'number',
'custom_attributes' => array(
'step' => 'any',
'min' => '0'
)
)
);
echo '</div>';
}
function woo_add_custom_general_fields_save( $post_id ){
// Number Field
$woocommerce_number_field = $_POST['_gram'];
if( !empty( $woocommerce_number_field ) )
update_post_meta( $post_id, '_gram', esc_attr( $woocommerce_number_field ) );
}
On my pages I'm using:
get_post_meta( get_the_ID(), '_gram', true );
To show the value and that work perfect.
Now I want to show this same value under the product name in my cart and in the email confirmations.
But I cant figure out how to do this.
Does anyone knows how to do this?

Answer 1

Well it's a long process, you have to implement two filters & one action to accomplish this.
Also there is a plugin for this exact purpose along with lot of other options related to woocommerce custom fields.
Here is the direct solution for your question.
/**
* Here we are trying to add your custom data as Cart Line Item
* SO that we can add this custom data on your cart, checkout, order and email later
*/
function save_custom_data( $cart_item_data, $product_id ) {
$custom_data = get_post_meta( $product_id, '_gram', true );
if( $custom_data != null && $custom_data != "" ) {
$cart_item_data["gram"] = $custom_data;
}
return $cart_item_data;
}
add_filter( 'woocommerce_add_cart_item_data', 'save_custom_data', 10, 2 );
/**
* Here we are trying to display that custom data on Cart Table & Checkout Order Review Table
*/
function render_custom_data_on_cart_checkout( $cart_data, $cart_item = null ) {
$custom_items = array();
/* Woo 2.4.2 updates */
if( !empty( $cart_data ) ) {
$custom_items = $cart_data;
}
if( isset( $cart_item["gram"] ) ) {
$custom_items[] = array( "name" => "Gram", "value" => $cart_item["gram"] );
}
return $custom_items;
}
add_filter( 'woocommerce_get_item_data', 'render_custom_data_on_cart_checkout', 10, 2 );
/**
* We are adding that custom data ( gram ) as Order Item Meta,
* which will be carried over to EMail as well
*/
function save_custom_order_meta( $item_id, $values, $cart_item_key ) {
if( isset( $values["gram"] ) ) {
wc_add_order_item_meta( $item_id, "Gram", $values["gram"] );
}
}
add_action( 'woocommerce_add_order_item_meta', 'save_custom_order_meta', 10, 3 );