Validation required for zip codes less than 6 digits

Question

we have custom module for entering zip codes in backend, only if those zip codes if we enter in shipping address, than it will display COD under payment method , otherwise it will hide COD.

Here problem is it is working only for 6 digits.

if we enter any below 6 digit zip codes in shipping address , its displaying COD. This is problem.

ex: 2,24, 246, 2468, 12345

but if we enter any 6 digit zip codes other than zipcodes which is present backend, its not displaying COD. This is fine.

ex: 123456, 333999, 666666

as validation is working fine for 6 digits we want for other digits also.

Observer.php

<?php
class Mfp_Cod_Model_Observer {

    public function getCashOnDelvery(Varien_Event_Observer $observer) {
        $event           = $observer->getEvent();
        $method          = $event->getMethodInstance();
        $result          = $event->getResult();
        $isModuleEnable = Mage::getStoreConfig('cod/cod/enable');

        if($isModuleEnable) {

            if($method->getCode() == 'cashondelivery' ){

                $quote = Mage::getSingleton('checkout/cart')->getQuote();
                $add = $quote->getShippingAddress();
                $postcode = $add->getData('postcode');

                $comparisonMode = Mage::getStoreConfig('cod/cod/mode');
                $zipCodes = Mage::getStoreConfig('cod/cod/zipcode');
                $isExist = false;

                if(trim($zipCodes) == '') {             
                    $result->isAvailable = true;
                } else {    

                    if(strpos($zipCodes, $postcode) !==  false) {
                        $isExist = true;
                    }


                    if($isExist != true) {

                        $zipCodesArray = explode(',', nl2br($zipCodes));
                        if(count($elementLineArray) > 1) {
                            foreach($zipCodesArray as $codzipLine) {
                                $elementLineArray = explode('-', $codzipLine);
                                if(count($elementLineArray) == 2 && ( $postcode >= $elementLineArray[0] && $postcode <= $elementLineArray[1] )) {
                                    $isExist = true;
                                    break;
                                } else if($postcode == $codzipLine) {
                                    $isExist = true;
                                    break;
                                }
                            }
                        }
                    }

                    $returnValue = '';
                        $returnValue = ($isExist)?true:false;

                    $result->isAvailable = $returnValue;

                }   

            } 
        }   
    }
}

config.xml

<?xml version="1.0"?>
<config>
  <modules>
    <Mfp_Cod>
      <version>1.0.0</version>
    </Mfp_Cod>
  </modules>
  <global>
          <models>
            <cod>
                <class>Mfp_Cod_Model</class>
            </cod>
        </models>

    <helpers>
      <cod>
        <class>Mfp_Cod_Helper</class>
      </cod>
    </helpers>
  </global>
    <frontend>
        <events>
            <payment_method_is_active>
                <observers>
                    <paymentfilter_payment_method_is_active>
                        <type>singleton</type>
                        <class>Mfp_Cod_Model_Observer</class>
                        <method>getCashOnDelvery</method>
                    </paymentfilter_payment_method_is_active>
                </observers>
            </payment_method_is_active>
        </events>
    </frontend>
</config> 

Answer 1

Try this code in Observer.php

<?php
class Mfp_Cod_Model_Observer 
{

    public function getCashOnDelvery(Varien_Event_Observer $observer) {
        $event           = $observer->getEvent();
        $method          = $event->getMethodInstance();
        $result          = $event->getResult();
        $isModuleEnable = Mage::getStoreConfig('cod/cod/enable');
        $returnValue = false;
        if($isModuleEnable) {

            if($method->getCode() == 'cashondelivery' ){

                $quote = Mage::getSingleton('checkout/cart')->getQuote();
                $add = $quote->getShippingAddress();
                $postcode = $add->getData('postcode');
                $comparisonMode = Mage::getStoreConfig('cod/cod/mode');
                $zipCodes = Mage::getStoreConfig('cod/cod/zipcode');
                $isExist = false;
                if(strlen($postcode) >= 6) {
                    if(trim($zipCodes) == '') {             
                        $result->isAvailable = true;
                    } else {    

                        if(strpos($zipCodes, $postcode) !==  false) {
                            $isExist = true;
                        }

                        if($isExist != true) {

                            $zipCodesArray = explode(',', nl2br($zipCodes));
                            if(count($elementLineArray) > 1) {
                                foreach($zipCodesArray as $codzipLine) {
                                    $elementLineArray = explode('-', $codzipLine);
                                    if(count($elementLineArray) == 2 && ( $postcode >= $elementLineArray[0] && $postcode <= $elementLineArray[1] )) {
                                        $isExist = true;
                                        break;
                                    } else if($postcode == $codzipLine) {
                                        $isExist = true;
                                        break;
                                    }
                                }
                            }
                        }
                        $returnValue = ($isExist)?true:false;
                        $result->isAvailable = $returnValue;
                    }
                }
                $result->isAvailable = $returnValue;   

            } 
        }   
    }
}