Redirect from URLs with Query Strings

Question

My old site had tens of thousands of no-longer-valid products with urls like http://example.com?product_id=123456.

They are all search-engine indexed and now resolve to 404 in Magento. I cannot possibly create a redirect for every single one.

How do I get them to resolve to my home page?

Answer 1

In this case,you can use event/observer and on event controller_front_init_before fire an observer.

First i guess that your old product id and new product id are same.

On that observer check query string($_SERVER['QUERY_STRING']) content

?product_id=productID pattern in url then basic of this redirect to current system product url.

Example:

Suppose,

Old system product url: http://example.com?product_id=123456

New system product url: http://example.com/abx.html

my code will be redirect http://example.com?product_id=123456 to http://example.com/abx.html using 301 redirection.

301 redirect, you will resolved SEO issue.

Here config.xml code:

 <global>
    <models>
      <magento67130>
        <class>StackExchange_Magento67130_Model</class>
        <resourceModel>magento67130_mysql4</resourceModel>
      </magento67130>
    </models>
    <events>
      <controller_front_init_routers> <!-- identifier of the event we want to catch -->
        <observers>
          <controller_front_init_before_handler> <!-- identifier of the event handler -->
            <type>model</type> <!-- class method call type; valid are model, object and singleton -->
            <class>magento67130/observer</class> <!-- observers class alias -->
            <method>redirectionProduct</method>  <!-- observer's method to be called -->
          </controller_front_init_before_handler>
        </observers>
      </controller_front_init_routers>
    </events>
  </global>

Observer.php code is below:

<?php
class StackExchange_Magento67130_Model_Observer
{

    public function redirectionProduct(Varien_Event_Observer $observer)
    {
        return;
        if($this->_getQueryString()){
            print_r($this->_getQueryString());

                // Check query string exits in product_id
            if(strpos($this->_getQueryString(),'product_id=')!== false){
                /* get Product ifd from query string */
                 $productid=str_replace('product_id=','',$this->_getQueryString());
                if(!empty($productid)):
                $product= Mage::getModel('catalog/product')->load($productid);
                 if ($product->getId()) {
                    echo $product->getProductUrl();
                     Mage::app()->getResponse()
                        ->setRedirect($product->getProductUrl(), 301)
                             ->sendResponse();

                             return;
                 }
                endif;
            }

        }
        //die();

    }
    /* Check here Request query string */
    protected function _getQueryString()
        {
            if (!empty($_SERVER['QUERY_STRING'])) {
                $queryParams = array();
                parse_str($_SERVER['QUERY_STRING'], $queryParams);
                $hasChanges = false;
                foreach ($queryParams as $key => $value) {
                    if (substr($key, 0, 3) === '___') {
                        unset($queryParams[$key]);
                        $hasChanges = true;
                    }
                }
                if ($hasChanges) {
                    return http_build_query($queryParams);
                } else {
                    return $_SERVER['QUERY_STRING'];
                }
            }
            return false;
        }
}

Answer 2

you have to create one little custom extension to redirect if product is not found in your database

here i have given working solution and its perfect worked for me

How to forward all the 404 Magento pages to the front page?

hope this will also work for you.