Calculate function definition location in OpenCart - php

Question

I just started studying OpenCart, downloaded latest version of opencart and reading the documentation about where to find the function definition of tax calculate function.
In the non admin side, opening any Products shows data with tax calculation. Here is code it uses it.
$this->tax->calculate($product_info['price'], $product_info['tax_class_id'], $this->config->get('config_tax'))
Is there any link to check the location of tax class for checking the calculate function definition?

Answer 1

Not quite sure what exactly do you want to achieve. But the calculate function you can find in system/library/cart/tax.php.
public function calculate($value, $tax_class_id, $calculate = true) {
if ($tax_class_id && $calculate) {
$amount = 0;
$tax_rates = $this->getRates($value, $tax_class_id);
foreach ($tax_rates as $tax_rate) {
if ($calculate != 'P' && $calculate != 'F') {
$amount += $tax_rate['amount'];
} elseif ($tax_rate['type'] == $calculate) {
$amount += $tax_rate['amount'];
}
}
return $value + $amount;
} else {
return $value;
}
}
Although in this file you will find a lot of interesting connected with tax processing in OpenCart.
If this information not enough - please, describe the desired result with more details and I will try to help.