woocommerce remove action based on product id - php

Question

everyone, i am trying to stop a plugin function from executing if a certain product id is in the cart. I have tried and written the following code and put them in my theme functions.php, but it doesn't seem to work. Instead, the whole page become blank. Can anyone help me out?
$found = false;
global $woocommerce;
foreach($woocommerce->cart->get_cart() as $cart_item_key => $values ) {
$_product = $values['data'];
if( $_product->id == 1097 ) {
$found = true;
}
}
if ($found){
remove_action('woocommerce_before_order_notes', array($wdt, 'show_field'), 20);
}
By itself, remove_action('woocommerce_before_order_notes', array($wdt, 'show_field'), 20); works. But once i tried to link it to work base on product id, the whole website just cannot load. Thank you!

Answer 1

The variable $wdt does not seam to be initialized. You should ether use the class name(string) or an instance of that class here.
An other guess is that your code runs before the action is added. Make sure you run your code on a later hook in the execution see this for reference: http://codex.wordpress.org/Plugin_API/Action_Reference#Actions_Run_During_a_Typical_Request
So if the code that add the hook runs at init, you can try to run your code at wp_loaded. Like this:
add_action('wp_loaded','my_remove_order_notes');
function my_remove_order_notes()
{
//Your code
}
Also, make sure that the priority parameter matches with the code where the action hook is added. The default priority is 10.
Edit:
Ok, you should not remove the filter. Filters are supposed to be used for manipulating the data and the return the new data back. Like this:
add_filter( 'woocommerce_checkout_fields' , 'custom_remove_order_comments', 99 );
function custom_remove_order_comments( $fields )
{
global $woocommerce;
foreach($woocommerce->cart->get_cart() as $cart_item_key => $values ) {
$_product = $values['data'];
if( $_product->id == 1097 ) {
unset($fields['order']['order_comments']); //Remove the order comments field
}
return $fields; //Return the data back to WooCommerce
}