[Zope] Displaying BLOB's with Zope

[Mark Evans]

Hi all,

I have been reading everything I can find on the web on this and just c=
an't find
exactly what I need.  I hope someone can help.

I have recently begun learning about BLOBs in Oracle8i.  I have success=
fully
created a table 'blobtest' consisting of two fields, 'ID' and 'Image' a=
nd loaded
a jpeg file into it using sqlloader.  I am using DCOracle2, Zope2.5.1,M=
ozilla1.x
and Python2.2.1.  Zope and Oracle are running on Solaris and my client =
is W2K.

I have an external method called 'blobtest' that retrieves the blob:

import string, DCOracle2 as dco
def main ():
    dCon =3D dco.connect("foo/moo@myfoo")
    dCur =3D dCon.cursor()
    sql =3D "select image from blobtest where id=3D'1'"
    dCur.execute(sql)
    result =3D dCur.fetchone()
    lob =3D result[0]
    pic =3D lob.read()
    return pic

I have a DTML method that calls the External Method:

<dtml-var standard_html_header>
Method 1: Display image in-line, retrieved by External Method<BR>
<img src=3D&dtml-blobtest;>
</p>
<dtml-var standard_html_footer>

What I want it to do is display the image on the html page.  What it do=
es is
open a browser dialog box asking me to select an application to open a =
file of
type 'application/octet-stream'.  If I select an image viewing program =
like
IrfanView, Irfan tells me the file is of type jpeg, but missing the fil=
e
extension.  When I click 'ok' it displays the correct image and display=
s it
properly.

This leads me to suspect that a) the blob that is returned does not hav=
e a name
and therefore doesn't have a file type extension and b) my problem prob=
ably has
something to do with setting the content-type header properly to image/=
jpeg.
How do I do this using an external method?

Alternatively, I have tried to adapt the MySQL HowTo by murphy (
http://www.zope.org/Members/murphy/MySQL-BLOBs) in the following way:

Created a python script called 'retrieveImage':

    photo =3D context.getImage()
    container.REQUEST.RESPONSE.setHeader('content-type', 'image/jpeg')
    return  photo[0].image

which calls the ZSQL method 'getImage':

    select image from blobtest
    where id=3D'1'

When I click on the 'test' tab for the python script, I get the followi=
ng
message:
The image "http://foo.com/blobtest2/retrieveImage" cannot be displayed,=
 because
it contains errors.

What am I missing here?  Thanks in advance for the help.

Regards,

Mark Evans=