On Wed, Nov 4, 2009 at 11:31 PM, Stuart Moffatt <[email protected]>wrote:
> Nick,
>
>
> > Can you clarify what you mean by 'java loader' and 'hosted mode'?
>
> My java loader is a servlet which loads a CSV from disk, processes it and
> persists entities to the datastore. The CSV has the values for the
> properties I want my entity to have. The CSV and the data it points to is in
> WEB-INF, so I can get away with loading large sets in hosted mode and
> smaller sets in production (because of the static file limit and request
> timeout it is not possible to load all of my data in production using this
> method). The Kind is created when I persist that first entity. This is
> functionally similar to a python bulk loader, except it is a one-off
> servlet, and does not come with all of the configuration and transport
> mechanism options that provided by the python SDK.
>
>
> > In the Python SDK, entities are named after the unqualified name of the
> class, by default - so a 'Film' gets loaded with an entity name of 'Film'.
> You can specify a custom entity type name with the kind() method. I'm still
> not hugely familiar with Java, so I'm not sure under which conditions it
> will use qualified and unqualified names - basically, you need to match
> those with your Python loaders.
>
> At one point I tried to convince bulkloader.py (using
> --kind=package.MyClass) and my custom bulk loader
> (bulkloader.Loader.__init__(self, 'package.MyClass')) to accept the full
> java package name, but even when I used namespaces in the python model, this
> did not work.
>
> Perhaps a python example for the kind() method you mention? Am I correct in
> assuming that I should provide a kind() method in my custom bulk loader
> which overrides the default in much the same way as handle_entity() or
> generate_key() gives you a hook into those functions?
>
Pretty much, except kind() is a method for Model classes, not loaders. Like
this:
class Foo(db.Model):
@classmethod
def kind(self):
return 'my.Foo'
>
> In other words, should I try this?
>
> ================================
> class MyClass(db.Model):
> name = db.StringProperty()
> other_property = db.StringProperty()
>
> class MyClass(bulkloader.Loader):
> def __init__(self):
> bulkloader.Loader.__init__(self, 'MyClass',
> [('name', str),
> ('other_property', str)
> ])
>
> def kind(self, entity):
> return 'package.MyClass'
> ================================
>
>
> I understand if you can't provide a Java example, no worries. In lieu of
> that, could you provide a full example of customizing the python model's
> namespace using the kind() method in a custom bulkloader, along with the
> command line syntax to push it (with appcfg.py using the custom loader).
>
As above, and specify the kind you declared in the Python module on the
command line and in the loader.
> And if that's not enough <grin> it would be good to see the query syntax in
> the runtime application (e.g. "SELECT * from package.MyName" with the right
> python import statements).
>
If you're using GQL, you need to use the kind name, not the class name (so
in this example it would be "SELECT * FROM my.Foo").
-Nick
>
> Thanks for your help on this.
>
> Stuart
>
--
Nick Johnson, Developer Programs Engineer, App Engine
Google Ireland Ltd. :: Registered in Dublin, Ireland, Registration Number:
368047
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