Styjun

I have a code that displays the checkbox on the product edit page.

Here is my code:

// Display Roast Level Custom Fields
add_action( 'woocommerce_product_options_general_product_data', 'woo_roast_general_fields' );

function woo_roast_general_fields() 
// Create a custom checkbox field

// Checkbox
woocommerce_wp_checkbox( 
array( 
 'id' => '_roast', 
 'label' => __('Roast Level', 'woocommerce' ), 
 'description' => __( 'Enable roast level!', 'woocommerce' ) 
)
); 



// Save Fields
add_action( 'woocommerce_process_product_meta', 'woo_roast_general_fields_save' );

/** Hook callback function to save custom fields information */
function woo_roast_general_fields_save( $post_id ) 

// Save Checkbox
$checkbox = isset( $_POST['_roast'] ) ? 'yes' : 'no';
update_post_meta( $post_id, '_roast', $checkbox );

When you click on this checkbox, on the page of a single product, the selection field should be displayed. After selecting the options, these data should be displayed in the shopping cart, on the checkout page, on the Thank You page, email and when editing the order.

Here is my second code:

// The product custom field before add-to-cart button 
add_action( 'woocommerce_before_add_to_cart_button', 'woo_roast_custom_field' );

function woo_roast_custom_field() 
global $product;

echo '<div>';

woocommerce_form_field( 'roast_custom_field', array(
 'type' => 'select',
 'class' => array('my-field-class form-row-wide'),
 'label' => __('Roast Level'), 
 'required' => false,
 'options' => array( 
 '' => 'Please select', 
 'Blue' => 'Blue', 
 'Rare' => 'Rare',
 'Medium Rare' => 'Medium Rare',
 'Medium' => 'Medium',
 'Medium Well' => 'Medium Well',
 'Well Done' => 'Well Done'
)), '' );

echo '</div>';


// Save the new unique value in the array of values (as product meta data)
add_action( 'woocommerce_add_to_cart', 'roast_custom_field_add_to_cart', 20, 6 );

function roast_custom_field_add_to_cart( $cart_item_key, $product_id, $quantity, $variation_id, $variation, $cart_item_data )

if( isset($_POST['roast_custom_field']) )
 // Get the array of existing values
 $roast_values = (array) get_post_meta( $product_id, '_roast_custom_field_values', true );
 // append the new value to the array of values
 $roast_values[] = sanitize_text_field( $_POST['roast_custom_field'] );
 // Save the appended array
 update_post_meta( $product_id, '_roast_custom_field_values', $roast_values );

But unfortunately, I do not know how to make a condition so that when you click on the checkbox, a selection box will appear on the page of a single product.

It should be noted that if the checkbox is not active, then the selection field should not be displayed on the page of a single product.

Also, I'm not quite sure about the correctness of the code when saving data.

I ask for your help!