[Zope] Re: [Skinscript] unable to update property

[Steve Spicklemire]

Hi Dirksen,

   I think that WHEN OBJECT CHANGED is used when some code tries to 
change a DataSkin attribute and you need to update some external source.
So... an appropriate thing to do would be to call an SQL method, or
talk to another Specalist which needs to be notified .. etc. I think
that you may be 'double' chaning... e.g., some code tries to change
the transaction count... this fires a trigger that *also* tries to change
the same thing... hence the conflic error. Can you share the code
that is firing the trigger? (TransCount is used to keep track of 
the shopper's 'current' transaction. In the current implementation
It is used to calculate a 'basked id' since each shopper can have
mulitiple baskets, as they return for more shopping later.. ) TransCount
should only be modified when a shopper completes a transaction and
they need a 'new' basket. Does that help?

-steve


>>>>> "Dirksen" == Dirksen  <dirksen_lau@yahoo.com> writes:

    Dirksen> Hi Steve,

    Dirksen> I ran into a very tricky problem when developing a site
    Dirksen> with emarket. Here is the structure of my site:

    Dirksen> root |--acl_users(Membership product) |--emarket
    Dirksen> |--shoppers

    Dirksen> The acl_users is an instance of Membership product, which
    Dirksen> is as a specialist as shoppers, and they both have a
    Dirksen> WebIC_MemberClass zclass as their rack object class. The
    Dirksen> difference is that, acl_users stores WebIC_MemberClass
    Dirksen> persistently, while shoppers just reflects that
    Dirksen> storage. Here is the skinscript for shopper's rack:

    Dirksen> WITH acl_users.getItem(self.id) COMPUTE oo=RESULT

    Dirksen> WITH self.oo COMPUTE email, transCount

    Dirksen> WHEN OBJECT CHANGED STORE transCount USING
    Dirksen> self.oo.propertysheets.webic.manage_changeProperties(transCount=self.transCount)

    Dirksen> When emarket trying to increment a shopper's transCount,
    Dirksen> I ran into a "ZODB.POSException.ConflictError". The
    Dirksen> following is the traceback: Traceback (innermost last):
    Dirksen> File C:\WebSite\lib\python\ZPublisher\Publish.py, line
    Dirksen> 222, in publish_module File
    Dirksen> C:\WebSite\lib\python\ZPublisher\Publish.py, line 199, in
    Dirksen> publish File C:\WebSite\lib\python\ZPublisher\Publish.py,
    Dirksen> line 199, in publish File
    Dirksen> C:\WebSite\lib\python\ZPublisher\Publish.py, line 199, in
    Dirksen> publish File C:\WebSite\lib\python\ZPublisher\Publish.py,
    Dirksen> line 195, in publish File
    Dirksen> C:\WebSite\lib\python\Zope\__init__.py, line 188, in
    Dirksen> zpublisher_exception_hook (Object: ProviderContainer)
    Dirksen> File C:\WebSite\lib\python\ZPublisher\Publish.py, line
    Dirksen> 175, in publish File
    Dirksen> C:\WebSite\lib\python\Zope\__init__.py, line 235, in
    Dirksen> commit File C:\WebSite\lib\python\ZODB\Transaction.py,
    Dirksen> line 251, in commit File
    Dirksen> C:\WebSite\lib\python\ZODB\Connection.py, line 351, in
    Dirksen> commit (Info: (('*hdVMVCvgk/wIgJaYf/nkEA==',
    Dirksen> 'WebIC_MemberClass'), '\000\000\000\000\000\000d\357',
    Dirksen> '')) File C:\WebSite\lib\python\ZODB\FileStorage.py, line
    Dirksen> 664, in store (Object: C:\WebSite/var/Data.fs)
    Dirksen> ConflictError: ('\0039\323C4=\266\210',
    Dirksen> '\0039\323B\375\036\270U')

    Dirksen> Is it something wrong with my skinscript?

    Dirksen> cheers Dirksen



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