SQLFORM onvalidate

[leone]

I have questions about SQLFORM onvalidate.
Before inserting a row I have to resize an image by PIL and push
b64encoded bytes on a blob field.
So I have defined onvalidate=DoSomething in SQLFORM.
DoSomething has form as input arg, resize image as thumbnails, encode
it and push in form.vars.myblob
(or db.mytable.myblob???).
The new record is OK, but blob field is empty.
Can someone orient me?

[leone]

excuse me: onvalidation not onvalidate.

[leone]

Solved:

if form.accepts(request.vars, session, keepvalues=True,
onvalidation=WriteThumb):
.........

def WriteThumb(form):
i = cStringIO.StringIO()
o = cStringIO.StringIO()
i.write(form.vars.imgfile.value)
i.seek(0)
im = Image.open(i, 'r')
im.thumbnail((100,100),Image.ANTIALIAS)
im.save(o,'jpeg')
form.vars.thumbnail = base64.b64encode(o.getvalue())
o.close()
i.close()

<img src="data:image/jpeg;base64,{{=row['thumbnail']}}"
alt="Thumbnail photo" />

[leone]

I forget:

from PIL import Image