Thanks, it finally worked. Following your suggestion, what I did is:
1. in class body, define:
content = db.BlobProperty(required=False) # notice required
is set to False
2. in __init__(arg1, arg2, ...):
self.content = ''
Then
self.content += src
doesn't complain anymore.
When accessing, it returns a db.Blog doesn't sound too foreign to me. For
now, I just think it as a customized type caster in C++.
But I am facing another problem now, I will post it in a new thread
'Different behavior in Debug run'.
Regards,
Will
On Tue, Jan 27, 2009 at 8:31 PM, Alexander Kojevnikov <
alexan...@kojevnikov.com> wrote:
>
> When creating an UploadStorage entity, you should initialise the
> content property:
>
> my_entity = UploadStorage(content='')
>
> or:
>
> my_entity = UploadStorage()
> my_entity.content = '' # or whatever your initial value is
>
> I know, it a bit confusing. When you define the property in the class,
> UploadStorage.content is an instance of db.BlobProperty.
>
> But when you access it after the entity is created, it returns the
> actual value of the property, which is of db.Blob type (subclass of
> str).
>
>
> On Jan 27, 10:13 pm, Will <vocalster....@gmail.com> wrote:
> > I rewrote it, now the error message became
> >
> > unsupported operand type(s) for +=: 'NoneType' and 'str'
> >
> > pointing at
> >
> > self.content += src
> >
> > Seems *content* was not constructed in modified __init__. If I added
> >
> > self.content = db.BlobProperty(required=True)
> >
> > into __init__ while keeping the definition in the class body, I got
> >
> > Property content must be convertible to a Blob instance (Blob() argument
> > should be str instance, not BlobProperty)
> >
> > Seems this time* content* was constructed but in __init__() somehow it
> > wanted to initialize it by a Blob instance, not BlobProperty?!
> >
> > Will
> >
> > On Tue, Jan 27, 2009 at 6:43 PM, Alexander Kojevnikov <
> >
> > alexan...@kojevnikov.com> wrote:
> >
> > > Rewrite your UploadStorage class to declare the module properties in
> > > the class body, not in the __init__ method. App Engine forwards access
> > > to property definitions to the actual property values, creation of the
> > > properties in __init__ is probably not compatible with it.
> >
> > > For example, when you access self.content in your append() method, GAE
> > > returns the value of the append property, not the property definition.
> >
> > > Try this code:
> >
> > > class UploadStorage(db.Model):
> > > content = db.BlobProperty(required=True)
> > > last_change = db.DateTimeProperty(required=True, auto_now=True)
> > > field_name = db.StringProperty(required=True, default=u'')
> > > ......
> >
> > > def __init__(self, field_name, file_name, content_type,
> > > content_length, charset):
> > > if field_name:
> > > self.field_name = field_name
> >
> > > def append(self, src):
> > > self.content += src
> >
> > > On Jan 27, 9:25 pm, Will <vocalster....@gmail.com> wrote:
> > > > Here you go,
> >
> > > > ------------------------------
> > > > class UploadStorage(db.Model):
> > > > def __init__(self, field_name, file_name, content_type,
> > > content_length,
> > > > charset):
> > > > self.content = db.BlobProperty(required=True)
> > > > self.last_change = db.DateTimeProperty(required=True,
> > > auto_now=True)
> > > > self.field_name = db.StringProperty(required=True,
> default=u'')
> > > > ......
> >
> > > > if (field_name):
> > > > self.field_name = field_name
> >
> > > > def append(self, src):
> > > > self.content += src
> > > > -------------------------------------
> > > > class GAEUploadedFile(UploadedFile):
> > > > def __init__(self, field_name, file_name, content_type,
> > > content_length,
> > > > charset):
> > > > self.__storage = UploadStorage(field_name, file_name,
> > > content_type,
> > > > content_length, charset)
> > > > ......
> >
> > > > def write(self, content): # append
> > > > self.__storage.append(content)
> > > > self.size = len(self.__storage.content)
> >
> > > > Thanks,
> >
> > > > Will
> >
> > > > On Tue, Jan 27, 2009 at 7:47 AM, Alexander Kojevnikov <
> >
> > > > alexan...@kojevnikov.com> wrote:
> >
> > > > > > No, doesn't work. I got
> >
> > > > > > unsupported operand type(s) for +=: 'BlobProperty' and 'str'
> >
> > > > > > Same as before.
> >
> > > > > Could you post here all related code, including the construction of
> a
> > > > > Storage entity?
> >
>
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