[Zope3-Users] Re: IField in Object(Field): RequiredMissing

[Christian Lück]

Daniel Nouri wrote:
>> 
>> There is a nice and helpfull example in ++apidoc++: Book --> Widgets and
>> Forms --> Advanced Widgets
>> Please also refer to srichter's book, chapter 8.3 (p. 54).
> 
> I don't have Stephan's book around right now.  

Isn't it online on the zope3 homepage?


> But I'm using the Object
> field just as you suggest.  But that doesn't work.  The error is the
> same as described above.  I just wanted to reproduce it in the
> interactive interpreter.
> 

I'm not sure if you use it like it was intended to be used ;)
Here we go on the command line:

clueck at aeolos:~$ export PYTHONPATH=/usr/local/Zope-3.2.0b2/lib/python/
clueck at aeolos:~$ python2.4
Python 2.4.2 (#1, Jan  1 2006, 20:27:29)
[GCC 3.3.5 (Debian 1:3.3.5-13)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from zope.schema import TextLine
>>> from zope.schema import Object
>>> from zope.interface import Interface, implements

First we define an Interface:

>>> class IPerson(Interface):
...     first = TextLine(title=u"Firstname", required=False)
...     last = TextLine(title=u"Lastname", required=True)
...

Then we write a class that implements it.
We use FieldProperty to check your attributes against our schema:

>>> from zope.schema.fieldproperty import FieldProperty
>>> class Person(object):
...     implements(IPerson)
...     first = FieldProperty(IPerson['first'])
...     last = FieldProperty(IPerson['last'])
...

Now let's create an instance:

>>> k = Person()
>>> k.first = 'Franz'
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/fieldproperty.py",
line 52, in __set__
    field.validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_bootstrapfields.py",
line 138, in validate
    self._validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_bootstrapfields.py",
line 263, in _validate
    super(MinMaxLen, self)._validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_bootstrapfields.py",
line 165, in _validate
    raise WrongType(value, self._type)
zope.schema._bootstrapinterfaces.WrongType: ('Franz', <type 'unicode'>)

It insists on unicode, so we give it unicode:

>>> k.first=u'Franz'
>>> k.last=u'Kafka'

We create a second person, but this time we leave the 'last' attribute
which is 'required' following our IPerson schema.

>>> f = Person()
>>> f.first = u'Felice'

Now we step forward to zope.schema.Object
Again we define an Interface and an implementing class:

>>> class ILetter(Interface):
...     sender = Object(title=u"From", schema=IPerson)
...     addressee = Object(title=u"To", schema=IPerson)
...     date = TextLine(title=u"Date")
...
>>> class Letter(object):
...     implements(ILetter)
...     sender = FieldProperty(ILetter['sender'])
...     addressee = FieldProperty(ILetter['addressee'])
...     datum = FieldProperty(ILetter['date'])
...
>>> l = Letter()

Now let's see if zope.schema.Object works:

>>> l.sender = u'Kafka'
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/fieldproperty.py",
line 52, in __set__
    field.validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_bootstrapfields.py",
line 138, in validate
    self._validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_field.py",
line 413, in _validate
    raise SchemaNotProvided
zope.schema.interfaces.SchemaNotProvided

Okay, this was nice.

>>> l.sender = k
>>> l.sender
<__main__.Person object at 0xb7cdbeec>

Now let's have an other test:

>>> l.addressee = f
Traceback (most recent call last):
  File "<stdin>", line 1, in ?
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/fieldproperty.py",
line 52, in __set__
    field.validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_bootstrapfields.py",
line 138, in validate
    self._validate(value)
  File
"/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/schema/_field.py",
line 418, in _validate
    raise WrongContainedType(errors)
zope.schema.interfaces.WrongContainedType: []

But we remember Felice's lastname:

>>> f.last = u'Bauer'
>>> l.addressee = f

Hey, check passes now. Everything seems ok with it.



Regards,
Christian