Magento – Call to a member function getBackend() on a non-object

adminerrormagento-1.7

Client is trying to setup promotions via the admin but when saving and applying the promotion the server logs the following error (admin return blank screen):

PHP Fatal error: Call to a member function getBackend() on a
non-object in /app/code/core/Mage/Catalog/Model/Resource/Product/Collection.php
on line 855

Unable to find any info regarding this type of error, what may be causing it, or how to correct it.

Thanks for your help!

Best Answer

Use the following script to list product attributes with non-existant backend models:

umask(0);
require 'app/Mage.php';    
Mage::setIsDeveloperMode(true);
Mage::app('admin');

$entityType = Mage::getSingleton('eav/config')->getEntityType('catalog_product');
foreach ($entityType->getAttributeCollection() as $attribute) {
    if ($backendClass = $attribute->getBackendModel()) {
        try {
            class_exists(Mage::getConfig()->getModelClassName($backendClass), true);
        } catch (Exception $e) {
            echo "Not found the backend model {$backendClass} for product attribute {$attribute->getAttributeCode()}\n";
        }
    }
}

Related Solutions

Magento – Notice: Trying to get property of non-object

I had this same problem while installing an instance of Magento within our testing environment. Because I downloaded Magento Enterprise on my local machine and pushed the code to the test environment using GIT, my .gitignore file left out the enterprise.xml and config.xml. Because these files were missing it generated the error message described by the OP. Once in place, it sent me to the Magento Install page! Hope that helps someone out there.

Magento – Call to a member function rewrite() on a non-object in app/code/core/Mage/Core/Controller/Varien/Front.php on line 165

If you look at the file to which magento points out, you can find the below line which comes inside dispatch method

File : app/code/core/Mage/Core/Controller/Varien/Front.php

$this->_getRequestRewriteController()->rewrite();

The error says rewrite() is calling on a non-object. This means that, $this->_getRequestRewriteController() provides you a non-object (most probably it returns an empty value).

Why $this->_getRequestRewriteController() gives you a non-object ? In order to find the reason, let us have a look on this method definition.

protected function _getRequestRewriteController()
{
    $className = (string)Mage::getConfig()->getNode('global/request_rewrite/model');

    return Mage::getSingleton('core/factory')->getModel($className, array(
        'routers' => $this->getRouters(),
    ));
}

The method just trying to create a model instance of $className. Here $className holds a value which is returned by $className = (string)Mage::getConfig()->getNode('global/request_rewrite/model');. The default value which return by this call is core/url_rewrite_request. This means the method _getRequestRewriteController() is supposed to return an instance of model class Mage_Core_Model_Url_Rewrite_Request by defalt.

Based on this analysis, the error may be caused due to

You may have a wrong class name in the above specified node. app/code/core/Mage/Core/etc/config.xml is used to define this node value. Since it is a core file, alternation happens here may be a rare chance. There is a possibility of rewriting this node by any external plugins. So this should be validated first.
Ultimately your magento application do not have the file which defines this class Mage_Core_Model_Url_Rewrite_Request which normally appers at app/code/core/Mage/Core/Model/Url/Rewrite/Request.php
I have found out some threads, which gives a hint that permission problems on var/cache directory may also cause this weird issue.

Hope that helps.

Best Answer

Related Solutions

Magento – Notice: Trying to get property of non-object

Magento – Call to a member function rewrite() on a non-object in app/code/core/Mage/Core/Controller/Varien/Front.php on line 165

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