While trying to trap the Event for Product Detail page in Magento facing issue

Question

I am using magento 1.9.1.0 in that i want to trap the event observer for product detail page .So for that we had created a custom observer and it is working properly for target_path url present in core_url_rewrite like (1.e catalog/product/view/id/1241641/category/352/store/2) but when i am using request path for the same (i.e /women/accessories/handbags/bag.html) then we are getting "The page you requested was not found".

My custom Module details are given below

Observer.php

class Gamer_CustomProduct_Model_Observer {

    public function getProductView(Varien_Event_Observer $observer) {

            echo "In getProductView";
            exit;

            }

} 

Config.xml

<config>
    <modules>
        <Gamer_CustomProduct>
            <version>0.1.0</version>
        </Gamer_CustomProduct>
    </modules>
    <global>
        <models>
            <customproduct>
                <class>Gamer_CustomProduct_Model</class>
            </customproduct>
        </models>
        <events>
            <catalog_controller_product_init_before> 
                <observers>
                    <catalog_controller_product_init_before_handler> 
                        <type>model</type> 
                        <class>customproduct/observer</class> <!-- observers class alias -->
                        <method>getProductView</method>  
                    </catalog_controller_product_init_before_handler>
                </observers>
            </catalog_controller_product_init_before>
        </events>

    </global>
</config>

Answer 1

You should observe some generic event, such as controller_front_send_response_before and check if 404 page is going to be rendered. I show you an approach using a 301 redirect

public function yourFunction($observer){

    $resp = $observer->getEvent()->getFront()->getAction()->getRequest();
    if ($resp->getActionName() == 'noRoute'){

        $requestUri = $resp->getRequestString();
        // match this with your url rewrites table
        // maybe you should want to trim the / in $requestUri, print_r() it
        // if it is found then...
        header("Location: " . Mage::getBaseUrl() . $yourMatchedUrl, 301);
        exit;
    }

}