[Zope] Header information on file upload

[Martin Gebert]

Hi!

In my HowTo about dealing with BLOBs 
<http://www.zope.org/Members/murphy/MySQL-BLOBs> I use a rather 
unelegant but working method to get the content type of an uploaded 
file. Stefan Tjarks has now drawn my attention to the Header attributes 
of the uploaded form data, namely the "Content-Type" attribute which 
seems to reveal the MIME type (photo.headers['Content-Type'] for the 
given exsample).
My sorrow is now that this information isn't 100 % reliable, 'cause the 
Zope core (esp. the Image and File classes) doesn't seem to use this 
possibility either, but implements it's own methods which I use in the 
HowTo, too. The responsible class ZPublisher.HTTPRequest.FileUpload 
seems only to reach through the header information from the browser. 
Also I've learned through SelfHTML that the MIME type support of 
browsers has holes sometimes, as described for the accept attribute of 
the <form> tag.
Does anybody have further information on that issue, and why 
headers['Content-Type'] isn't used by Zope (it is, in fact, but in 
ZPublisher for seemingly other purposes)?

Martin