NameChooser in zope.app.container.contained sometimes doesn't choose a valid name and raises an exception

[Christian Zagrodnick]

The INameChooser interface isn't very explicit about chooseName's behaviour:

    def chooseName(name, object):
        """Choose a unique valid name for the object

        The given name and object may be taken into account when
        choosing the name.
        """

For me this reads: choose a name which I can use and never raise an exception. Currently chooseName can raise a UserError: "Names cannot begin with '+' or '@' or contain '/'"

I suggest letting chooseName remove + and @ at the beginning and replace / by - to prevent that and to generate a valid name.

[Christophe Combelles (ccomb)]

discussed here:
http://mail.zope.org/pipermail/zope3-dev/2007-October/024141.html
and here:
http://mail.zope.org/pipermail/zope-dev/2008-February/030920.html

I also believe that chooseName should just choose a name, and not raise an exception.

chooseName should be implemented so that it agrees with checkName: if checkName does not allow some characters, chooseName should remove these characters in the generated name.
And the INameChooser interface should talk about this failsafe behaviour.

[Christophe Combelles (ccomb)]

Attached is a suggested fix + tests. Please check and confirm.

[Christophe Combelles (ccomb)]

commited in rev 87367

[Christophe Combelles (ccomb)]

released in zope.app.container 3.5.4

[Christian Theune (ctheune)]

That didn't work too well. We're now "vulnerable" to passing `None` as a parameter.

For one, this seems to not having had test coverage before your change, but it worked (one of our products relies on this). I'm willing to make the necessary changes if needed.

[Tres Seaver (tseaver)]

The affected code now lives in zope.container.contained.

[Christophe Combelles (ccomb)]

r111341
- chooseName now never fails if the suggested name is in the wrong type.
- checkName now checks the type first in checkName
- Convert most namechooser doctests into unittests
- Added more test cases

I'll backport into zope.app.container 3.5 and 3.6 maintenance branches

[Tres Seaver (tseaver)]

Released today w/ zope.container 3.11.1:

  http://pypi.python.org/pypi/zope.container/3.11.1