Question

I’ve been trying to set a tax rate or customer class rate for magento based on the discount code used. Im only using the discount code as I can use it for a input.

Does anyone have any idea how this can achieved or any pointers?

Kind Regards

Chris

Answer 1

This is what I ended up doing for this. Should prove quite useful. Copy this file app/code/core/Mage/Tax/Model/Calculation.php to app/code/local/Mage/Tax/Model/Calculation.php then on line 178 theres this function

 public function getRate($request)
    {
        if (!$request->getCountryId() || !$request->getCustomerClassId() || !$request->getProductClassId()) {
            return 0;
        }

    $cacheKey = $this->_getRequestCacheKey($request);
    if (!isset($this->_rateCache[$cacheKey])) {
        $this->unsRateValue();
        $this->unsCalculationProcess();
        $this->unsEventModuleId();
        Mage::dispatchEvent('tax_rate_data_fetch', array('request'=>$request));
        if (!$this->hasRateValue()) {
            $rateInfo = $this->_getResource()->getRateInfo($request);
            $this->setCalculationProcess($rateInfo['process']);
            $this->setRateValue($rateInfo['value']);
        } else {
            $this->setCalculationProcess($this->_formCalculationProcess());
        }
        $this->_rateCache[$cacheKey] = $this->getRateValue();
        $this->_rateCalculationProcess[$cacheKey] = $this->getCalculationProcess();
    }
    return $this->_rateCache[$cacheKey];
}

I’ve changed this to this. Its a hardcoded Discount Code and Product Tax Class Id based on my requirements for this project.

public function getRate($request)
    {
        if (!$request->getCountryId() || !$request->getCustomerClassId() || !$request->getProductClassId()) {
            return 0;
        }

    $cacheKey = $this->_getRequestCacheKey($request);
    if (!isset($this->_rateCache[$cacheKey])) {
        $this->unsRateValue();
        $this->unsCalculationProcess();
        $this->unsEventModuleId();
        Mage::dispatchEvent('tax_rate_data_fetch', array('request'=>$request));
        if (!$this->hasRateValue()) {
            $rateInfo = $this->_getResource()->getRateInfo($request);
            $this->setCalculationProcess($rateInfo['process']);
            $thisDiscountCode = Mage::getSingleton('checkout/session')->getQuote()->getCouponCode();
            $thisProductClassCode = $request->getProductClassId();
            if($thisDiscountCode == "0000" && $thisProductClassCode == "5"):
            $this->setRateValue(0);
            else:    
            $this->setRateValue($rateInfo['value']);
            endif;            
        } else {
            $this->setCalculationProcess($this->_formCalculationProcess());
        }
        $this->_rateCache[$cacheKey] = $this->getRateValue();
        $this->_rateCalculationProcess[$cacheKey] = $this->getCalculationProcess();
    }
    return $this->_rateCache[$cacheKey];
}

Cheers for the help on this