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RE: [Zope-dev] RFC: RelationAware class for relations between obj ects
by sean.upton＠uniontrib.com 08 May '03

08 May '03

More in response to Shane than to Max M: I thought that one of the continuing justification for ObjectHubs was that hubids were consistent across multiple mounted storages, but oids were not? How could the universal id problem be addressed at a lower level than Zope2 or Zope3 in this case? Sean -----Original Message----- From: Max M [mailto:maxm@mxm.dk] Sent: Thursday, May 08, 2003 10:47 AM To: Shane Hathaway Cc: zope-dev(a)zope.org Subject: Re: [Zope-dev] RFC: RelationAware class for relations between objects Shane Hathaway wrote: >> I was under the impression that the Objecthub is Zope specific. Is >> that so? Or is it a plain ZODB thing? > > It's Zope specific. But in plain ZODB, you can achieve pretty much > the same thing ObjectHub achieves using simple OIDs. So the > relationship code should allow, but not require, direct references > using OIDs. > > That might make you wonder why we need an object hub at all. The > difference between Zope and an average ZODB application is that Zope > lets you create a large multiuser system with many security contexts. > An object hub assists the process by restoring references in context > (i.e. with the correct context wrappers.) A simple ZODB application > generally has only one security context, so it doesn't need the extra > complexity. Then it starts to get amusing. One of the primary reasons for the objecthub was to enable relations. So if the relations get implemented in in ZODB but need some functionality, will it not end up as a duplication of efforts? regards max M _______________________________________________ Zope-Dev maillist - Zope-Dev(a)zope.org http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )

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RFC: RelationAware class for relations between objects
by roche＠upfrontsystems.co.za 08 May '03

08 May '03

There has been a lot of discussion about the need for a service that manages relations between objects on zope3-dev lately and in the past. I thought this would be a good time to share some code we have written to make relations a bit easier in Zope 2 and to invite some comments on it. The attached module provides a mixin class that collaborates with Max M's mxmRelations product almost like CatalogAwareness collaborates with the ZCatalog. I really hope that this can be an acceptable interim solution until relations are better managed by the ZODB or by some service in Zope 3. One area of contention is the overriding of __of__ to compute relations as attributes on objects. What kind of performance hit will this cause if one has a long chain of relations? I appreciate any comments. -- Roché Compaan Upfront Systems http://www.upfrontsystems.co.za

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mysql: broken abort hangs zope
by seb bacon 08 May '03

08 May '03

A client's site had been hanging under high loads. The problem appeared to be that the ZMySQLDA assumed transactions in the database even if the underlying tables were not transactional. I fixed it by changing the tables to be transactional. No more hangs. The abort was failing thus: 2003-05-08T13:32:59 ERROR(200) ZODB A storage error occured during transaction abort. This shouldn't happen. ...Transaction.py, line 392, in _commit_error AttributeError: Surrogate instance has no attribute '_p_oid' Under "normal" circumstances an aborted transaction against a non-transactional table produces a sensible error explaining what is going on. Here, somehow, the 'Surrogate' transaction had ended up with no attributes at all. 1) Where might those attributes have gone? 2) Why might this cause Zope to hang? Note I have only been able to reproduce the problem on the live server so far, and therefore I've not yet had an opportunity to debug in detail. seb -- [] j a m k i t seb bacon T: 020 7549 0520 F: 020 7490 1152 M: 07968 301 336 W: www.jamkit.com

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Getting object name in Standard_Error_Message
by Michael Best 08 May '03

08 May '03

Is there a variable one can call to get the object name that caused an error? 2.6.1 tracebacks don't appear to provide the object name. -Mike

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Product refresh causes database connections leaking
by Oliver Bleutgen 08 May '03

08 May '03

I'm developing a product (based on SimpleUserFolder), which adds a folder with some ZSQL methods to itself on instanciation. The ZSQL methods use a database adapter (Z Psyco DA 1.1.3, symptoms occur also with older versions). After some time things went awry, because the DA had lost its connection to the database and couldn't reconnect, because the max connections postgres would allow were used. Now I think I found the cause, because everytime I refresh my product, and the ZSQL Methods are used, the number of connections to postgres grows by 4. Anybody knows what exactly is to blame, zope's refresh procedure or the database adapter? cheers, oliver

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Is there any zope client outside of web?
by Chen Fu 07 May '03

07 May '03

Hi! Web interface short some feature in GUI like drag or drop, and WYSIWYG editor environment. Is there already any windows client？ ===== Remote Scensing Satellite Ground Station Chinese Academy of Science _________________________________________________________ Do You Yahoo!? 相见不如聊天!不出门一样面对面！网络摄像头对对派送中~赶快用你的雅虎电邮帐号参与吧…… http://cn.rd.yahoo.com/mail_cn/tag/?http://cn.messenger.yahoo.com/

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Ftp with property?
by Chen Fu 07 May '03

07 May '03

Hi! I had read article descripting next step of ftp in zope will take a xml to package the property of file. When we upload the file and this xml, property will add to the uploaded file in ZMI. Is it true? Is this feature already usable now? My project in my institute involving upload former office files(mostly doc pdf excel) to zope/plone in batch. Most important, keywords must be added to use the Topic Catalog feature in plone. So i could not use the ZMI or plone interface to add properties one by one. I must have such ftp feature as soon as possible. If can't get the feature in this version's zope, hope somebody show me how to edit the ftp server's source code to add it. I am not a skilled python programmer, but I will take a try. Thanks ===== Remote Scensing Satellite Ground Station Chinese Academy of Science _________________________________________________________ Do You Yahoo!? 相见不如聊天!不出门一样面对面！网络摄像头对对派送中~赶快用你的雅虎电邮帐号参与吧…… http://cn.rd.yahoo.com/mail_cn/tag/?http://cn.messenger.yahoo.com/

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restrictedTraverse() security problem
by Terry Hancock 07 May '03

07 May '03

[Resending to Zope-dev, because on reflection I think it belongs there -- is there such a thing as a Zope product/ component developer list, or is this it?] Hi All, I have a call like this in restricted code: Home.restrictedTraverse(username).profile() which should call a method "profile" on a "UserPB" object (this method is public information, and should be visible to anyone). The catch is that UserPB is a wrapper on a database record, which I'm adding by using a __bobo_traverse__ method: class Home(Folder): meta_type = 'Narya-Home' __implements__ = HomeAPI security = ClassSecurityInfo() security.setDefaultAccess("allow") # ... def __bobo_traverse__(self, REQUEST=None, name=None): """Get a UserFolder if it exists, or a UserPB.""" try: return getattr(self, name) except: return self.getUser(name) def getUser(self, username): """Retrieve UserPB object from username.""" return UserPB(self.DB._getUser(username=username)[0]).__of__(self) class UserPB(Acquisition.Explicit, Item): """Basic wrapper for user data from database.""" __implements__ = UserPBI # ... def __init__(self, sqlres): """ Create a UserPB object by wrapping the SQL search result. """ for k in sqlres.__record_schema__.keys(): setattr(self, k, getattr(sqlres, k)) Accessing this causes an error """ Error Type: Unauthorized Error Value: You are not allowed to access foo in this context """ (where "foo" is the actual username). There is such a user, and the wrapper works perfectly when called from unrestricted code, so the problem is definitely the security. Here's the tail end of the traceback: """ File /usr/local/narya/z2.5.1/lib/python/DocumentTemplate/DT_Util.py, line 159, in eval (Object: Home.restrictedTraverse(username).post_score(nposts, nrecent, nmarkup, ndoc, nfaq, nlink, ngallery, nproj)) (Info: username) File <string>, line 0, in ? File /usr/local/narya/z2.5.1/lib/python/OFS/Traversable.py, line 163, in restrictedTraverse (Object: Home) File /usr/local/narya/z2.5.1/lib/python/OFS/Traversable.py, line 130, in unrestrictedTraverse (Object: Home) Unauthorized: (see above) """ Which indeed is the security check: [OFS/Traversable.py]: """ if (not securityManager.validate(object, container, name, o)): raise Unauthorized, name """ So it seems I need to do something to "call off the dogs" here. I've already set my default policy in "Home" to "allow" -- what's missing? Do I have to explicitly call a security method to do that, or is there an attribute or something needed? Also, is it really the Home or the UserPB object whose security is not right? I have not yet been able to figure out where "validate()" is actually defined -- it seems the securityManager object expects to inherit or acquire it from somewhere. I realize there's probably another way to do the large task here, but there are a number of reasons why it's more convenient to do this mimicry trick to make a database record look like a simple child object of Home -- not least of which is that I want to handle them in parallel with persistent Zope objects ("UserFolder") which implement an identical "UserPBI" interface. Any suggestions or ideas would be very much appreciated! Thanks, Terry -- Terry Hancock ( hancock at anansispaceworks.com ) Anansi Spaceworks http://www.anansispaceworks.com

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StructuredText i18n patch
by Andrey Lebedev 06 May '03

06 May '03

Hi, FYI: I've updated my StructuredText unicode patch with unittests (as Andreas Jung requested). It's available here: http://www.zope.org/Members/kedder/stx_18n_patch Hope somebody will find it useful...:) -- Andrey Lebedev aka -.- . -.. -.. . .--. Homepage: http://micro.lt/~andrey/ Jabber ID: kedder(a)jabber.ru

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context getting clobbered
by Florent Guillaume 06 May '03

06 May '03

If someone has the time to look at it, there was a weird bug posted in the collector yesterday. http://collector.zope.org/Zope/902 -- Florent Guillaume, Nuxeo (Paris, France) +33 1 40 33 79 87 http://nuxeo.com mailto:fg@nuxeo.com

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