Woocommerce Products Custom Field - php

Question

I have added custom fields to my woocommerce products and have been able to enter and fill the custom field data on products. I am trying now to use the data from that custom field in a button I am adding on the woocommerce single product page.
The custom field is a URL for the product sample. I am then trying to add a "View Product Sample" button on the woocommerce single product page that navigates to the url entered int he custom field. Here is the code I have:
// 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;
// Text Field
woocommerce_wp_text_input(
array(
‘id’ => ‘product_sample’,
‘label’ => __( ‘Sample Product Link’, ‘woocommerce’ ),
‘placeholder’ => ‘http://’,
‘desc_tip’ => ‘true’,
‘description’ => __( ‘Enter the sample product link here.’, ‘woocommerce’ )
)
);
}
function woo_add_custom_general_fields_save( $post_id ){
// Textfield
$woocommerce_text_field = $_POST[‘product_sample’];
if( !empty( $woocommerce_text_field ) )
update_post_meta( $post_id, ‘product_sample’, esc_html( $woocommerce_text_field ) );
}
add_action(‘woocommerce_after_add_to_cart_button’,’cmk_additional_button’);
function cmk_additional_button() {
echo '<a href="CONTENT OF CUSTOM FIELD - URL" target="_blank" button
type="submit" class="button sample">View Product Sample</a>';
}
I need help determining how to get my custom field meta data into the link for the button that is echoed at the end of the code.
Thanks for any help anyone can give.

Answer 1

You Can use ACF plugin for it and call the shortcode on single product page
Reference Url:http://blog.adlivetech.com/get-custom-fields-woocomerce/

Answer 2

You need to use get_post_meta() function this way:
add_action( 'woocommerce_after_add_to_cart_button', 'cmk_additional_button' );
function cmk_additional_button() {
global $post;
$url = get_post_meta( $post->ID, 'product_sample', true );
echo 'View Product Sample';
}
Code goes in functions.php file of your active child theme (or theme) or also in any plugin file.
This should work.
In the code of your question you are using ’ and you should replace them by ' instead, to avoid php errors.