Patching the Magento USPS module

Since their last update on Jan 3rd, 2011 USPS has stopped working on all of my Magento distro’s. The reason for that is a change in USPS’ response XML values. Magento has its part of blame here, first for not patching it immediately (which again shows how much they care about the CE users) and second for not coding it properly in the first place – they’re using the method name (i.e. Express Mail) to see if that method is allowed from the admin, instead of using the CLASSID attribute.

This issue has been reported on magentocommerce.com bug tracking system and it’s also discussed in the forum. USPS makes it clear that they’ll discontinue all API versions prior RateV4 ad IntlRateV2:
“All Rate Calculator API integrators are encouraged to migrate to the latest API versions (RateV4, IntlRateV2):
RateV4 and IntlRateV2 will be the only Rate Calculator API versions to offer the full range of new products and functionality
Rate, RateV2, RateV3 and IntlRate will be retired in May 2011, requiring all integrators to migrate to the latest versions”

As explained on the forums, the fix is quite simple, as USPS only added the <sup>®</sup> which is the encoded (twice 🙂 ) version of the registered sign in a sup tag. Magento values are defined without those so when the code tries to match them it fails. All you have to do is clean that string and you’re good to go. I don’t like to modify core files so the fix involves copying app/code/core/Mage/Usa/Model/Shipping/Carrier/Usps.php to app/code/local/Mage/Usa/Model/Shipping/Carrier/ and working on the local version of Usps.php. Strip the special chars:

$mailService = str_replace('®', '', strip_tags(htmlspecialchars_decode(htmlspecialchars_decode((string)$postage->MailService))));

and

$svcDescription = str_replace('®', '', strip_tags(htmlspecialchars_decode(htmlspecialchars_decode((string)$service->SvcDescription))));

Here’s the archive with the patch. Just download it and unzip it in the root of your Magento distribution. USPS patch for Magento 1.4.2.0 (1039 downloads)

Note: This patch applies to Magento CE 1.4.2.0. For all other versions you will have to do it manually as explained above.