How to empty basket before adding a product - Open Cart

Question

Following this link: Opencart: Adding Buy Now Button in Opencart Product Page

I added the following script on my page:

 $('#button-cart-buy').bind('click', function() {
                $.ajax({
                    url: 'index.php?route=checkout/cart/add',
                    type: 'post',
                    data: $('.product-info input[type=\'text\'], .product-info input[type=\'hidden\'], .product-info input[type=\'radio\']:checked, .product-info input[type=\'checkbox\']:checked, .product-info select, .product-info textarea'),
                    dataType: 'json',
                    success: function(json) {
                        $('.success, .warning, .attention, information, .error').remove();

                        if (json['error']) {
                            if (json['error']['option']) {
                                for (i in json['error']['option']) {
                                    $('#option-' + i).after('<span class="error">' + json['error']['option'][i] + '</span>');
                                }
                            }

                            if (json['error']['profile']) {
                                $('select[name="profile_id"]').after('<span class="error">' + json['error']['profile'] + '</span>');
                            }
                        } 

                        if (json['success']) {window.location='<?php echo $this->url->link('checkout/checkout', '', 'SSL'); ?>'; 
                        }

                    }
                });
            });

However, I would like to empty the cart before adding the product in question.

Does anyone know how to do it or have any tips?

Answer 1

The simplest way to do this would be to edit the cart class /system/library/cart.php

Find this line (from a 1.5.5.1 install - any other version may vary slightly though unlikely to be majorly different)

public function add($product_id, $qty = 1, $option = array()) {

On a new line after it, add

$this->cart->clear();

And save. Note that this allows for a customer to add a quantity greater than 1 to a cart as long as it is the same product