def add_filename_to_metadata(ob, metadata, request, response):
try:
field = IPrimaryFieldInfo(ob).field
except TypeError:
return
value = field.get(ob)
if INamedFile.providedBy(value):
filename = getattr(value, 'filename', None)
if filename is not None:
metadata.insert(0, 'filename:%s' % filename.encode('utf-8'))
