[Z3-sqlos] Re: [z3] sqlos: add view for SQLOS objects

[Brian Sutherland]

On Sat, Jan 21, 2006 at 12:44:55AM +0000, Christian Lück wrote:
> Brian Sutherland wrote:
> > On Sat, Jan 07, 2006 at 06:20:42PM +0000, Christian Lück wrote:
> Whenever I try to add an item with a <browser:addForm> view, I get the
> follwing exception:
> 
> 2006-01-20T22:20:21 ERROR txn.-1236755536 Failed to abort resource
> manager: <transaction._transaction.DataManagerAdapter object at 0xb52ae6cc>
> Traceback (most recent call last):
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/transaction/_transaction.py",
> line 507, in abort
>     rm.abort(self)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/transaction/_transaction.py",
> line 634, in abort
>     self._datamanager.abort(transaction)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/app/rdb/__init__.py",
> line 445, in abort
>     self._dbconn.rollback()
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/app/rdb/__init__.py",
> line 391, in rollback
>     self.conn.rollback()
> NotSupportedError: (1196, "Warning:  Some non-transactionalchanged
> tables couldn't be rolled back")
> Traceback (most recent call last):
>   File "/usr/local/lib/python2.4/threading.py", line 422, in run
>     self.__target(*self.__args, **self.__kwargs)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/twisted/python/threadpool.py",
> line 149, in _worker
>     context.call(ctx, function, *args, **kwargs)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/twisted/python/context.py",
> line 59, in callWithContext
>     return self.currentContext().callWithContext(ctx, func,*args, **kw)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/twisted/python/context.py",
> line 37, in callWithContext
>     return func(*args,**kw)
> --- <exception caught here> ---
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/twisted/web2/wsgi.py",
> line 139, in run
>     result = self.application(self.environment, self.startWSGIResponse)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/app/wsgi/__init__.py",
> line 54, in __call__
>     request = publish(request, handle_errors=handle_errors)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/publisher/publish.py",
> line 146, in publish
>     publication.handleException(
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/app/publication/zopepublication.py",
> line 243, in handleException
>     transaction.abort()
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/transaction/_manager.py",
> line 107, in abort
>     return self.get().abort(sub, deprecation_wng=False)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/transaction/_transaction.py",
> line 507, in abort
>     rm.abort(self)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/transaction/_transaction.py",
> line 634, in abort
>     self._datamanager.abort(transaction)
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/app/rdb/__init__.py",
> line 445, in abort
>     self._dbconn.rollback()
>   File
> "/usr/local/src/Zope-3.2.0b2/build/lib.linux-i686-2.4/zope/app/rdb/__init__.py",
> line 391, in rollback
>     self.conn.rollback()
> _mysql_exceptions.NotSupportedError: (1196, "Warning:
> Somenon-transactional changed tables couldn't be rolled back")

I have seen this before and wondered if there should be a bare try:
except: clause around the rollback in zope.app.rdb.

If you can't rollback, you are lost anyway, no point in bringing the
whole transaction machinery down with you.

> 127.0.0.1 - - [20/Jan/2006:22:20:21 +0100] "POST
> /persons/+/AddPerson.html%3D HTTP/1.1" 500 201
> "http://localhost:8080/persons/+/AddPerson.html=" "Mozilla/5.0 (X11; U;
> Linux i686;de-DE; rv:1.7.10) Gecko/20050925 Firefox/1.0.4 (Debian
> package 1.0.4-2sarge5)"
> 127.0.0.1 - - [20/Jan/2006:22:20:21 +0100] "GET /favicon.ico HTTP/1.1"
> 404 4133 "-" "Mozilla/5.0 (X11; U; Linux i686; de-DE; rv:1.7.10)
> Gecko/20050925 Firefox/1.0.4 (Debian package 1.0.4-2sarge5)"
> 
> 
> To avoid this, I wrote a view class for my add-view. There I override
> the add() method which is inherited from
> zope.app.form.browser.add.AddView. It calls the add() method of
> the context, which - if I'm not totally wrong - should implemet IAdding.

Yes, indeed it should implement IAdding, and you can adapt your
SQLObjectContainer to that interface with this directive:

  <browser:view
      name="+"
      menu="zmi_actions" title="Add SQLObjects"
      for="sqlos.testing.sampleperson.IMultiContainer"
      permission="zope.ManageContent"
      class="zope.app.container.browser.adding.Adding"
      >
    <browser:page name="index.html" attribute="index"/>
    <browser:page name="action.html" attribute="action"/>
  </browser:view>

> from zope.app.form.browser.add import AddView
> 
> class PersonAddView(AddView):
> 
>     __used_for__ = IPerson
> 
>     def add(self, content):
>         """In sqlos we yust intantiate an object and then it appears
>         in the container, but we don't really add an object to a container.
>         So we override this method here."""
>         return content

This type of thing really shouldn't be necessary as adding objects to a
sqlos container should really be a no-op.

However I have a funny feeling that the interface declarations in SQLOS
need some tweaking. For instance it appears possible in the zmi to add
SQLOS objects even to normal Zope3 Folders. That is bound to fail unless
you use an AddView like the one above.

I'm sure a read about how to do this in Stephan Richter's book
somewhere...

> Its Registration:
> 
>   <addform
>       schema="sqlosperson.interfaces.IPerson"
>       content_factory="sqlosperson.person.Person"
>       class=".person.PersonAddView"
>       name="AddPerson.html"
>       label="Add Person"
>       permission="zope.ManageContent"
>       />
> 
> But if sqlos wants to make it easy to plug a rdb instead of ZODB, then
> having to change all your add views is not acceptable..
> I thought about rewriting __setitem()__ and __getitem()__
> for the container class - but as far as I see, it's yust coded the way I
> was thinking of. Well I really don't have an idea..

I think the problem here is that you are trying to add sqlos objects to
normal Zope3 folders. That is really a bad idea, and probably allowing
that is a bug from the sqlos side.

Patches/testcases welcome!

> 
> Regards,
> Christian
> 

-- 
Brian Sutherland

Metropolis - "it's the first movie with a robot. And she's a woman.
              And she's EVIL!!"