Cast for two

Saturday, May 02, 2009

links to JPEG images in ATOM feed entries must be typed image/jpeg

After some debugging, I found a nasty bug in an ATOM feed that validated by the W3C validator service. I was trying to parse image url's out of an ATOM feed. ATOM 1.0 feeds are defined by the RFC 4287. In paragraph "4.2.7.3. The "type" Attribute" it is defined that the type must conform to the syntax of a MIME media type. The MIME media type is in turn defined by RFC 4288. Media type registrations are listed by the IANA at: http://www.iana.org/assignments/media-types/
If we look up the media subtypes of image/ we find that JPEG images have MIME type image/jpeg . The feed I was parsing had images with MIME type image/jpg instead of image/jpeg as it should have been. Apparently the W3C validator does not validate the type of links. I reported the bug/unconformence. Hopely it will be fixed soon.
A handy list with all MIME types to be used as reference is also provided by w3cschools.