[Zope] adding properties trough pythonscript

[Sean Hastings]

> Hopefully, you observe that it does *NOT* depend on the type
> of errors you are trapping but whether or not you changed
> (in the try block) persistent state *before* the exception occurred
> (in this block).

I do not yet understanding that part. My second example was:


1	def fooEdit(self,REQUEST):
2		"foo is a string - foo2 is an int"
3		try:
4			self.foo = REQUEST.get('foo','')
5			self.foo2 = int(REQUEST.get('foo2',0)
6		except ValueError, e:
7			self.foo2 = 0


Here I am modifying the persistent object's "foo" property in line 4, then
trapping an exception that the "int" function could raise in line 5. Unless
line 4 can also raise a ValueError (and I don't think it can), why am I not
safe in assuming one of these three cases?

A.  A ValueError raised in line 5 will leave "foo" set properly from the
REQUEST, while "foo2" gets set to 0.

B.  Some other Exception raised in line 4 or 5 will cause Zope to roll back
the transaction and no properties are changed on this try.

C.  No Exceptions occur, and leave both properties are set correctly from
the REQUEST.

--Sean



> -----Original Message-----
> From: Dieter Maurer [mailto:dieter at handshake.de]
> Sent: Friday, October 22, 2004 1:40 PM
> To: Sean Hastings
> Cc: massimop at users.berlios.de; zope list
> Subject: RE: [Zope] adding properties trough pythonscript
>
>
> Sean Hastings wrote at 2004-10-21 16:22 -0400:
> >Cool!
> >
> >I already have a whole bunch of code that uses this sort of
> error checking,
> >and I wanted to make sure that as long as I was careful to specify the
> >errors I am trapping that I don't have to rewrite it all.
>
>
> --
> Dieter