August 2001 - Zope-Dev

Re: [Zope-dev] ComponentArchitecture thoughts
by Ken Manheimer 05 Aug '01

05 Aug '01

On Sat, 4 Aug 2001 15:05:21 +0200, Joachim wrote: > Before that, Tim McLaughlin wrote: > > I listened in on the chat regarding this and although I think the idea has > > merit, I'm not sure that it is vitally important right now. It could too > > quickly turn into a lot of burned time with nothing to show for it. [...] > One of the important points to make is that ZClasses (or a replacement for > them) as well as the security model are frequently used by Zope users (or > "configurators") , while the new components model will mainly be a benefit > for Zope programmers (i.e. people working on extending Zope rather than just > using it). So their impact might be much larger ... I'm going out on a limb, here. I've got a slightly sketchy understanding of the component architecture, myself. But my impression, from what i do understand, is that it will make it easy to do a lot of the things that bring people to ZClasses, and in a better way. At the least, i think it will significantly reduce the pressures that push people in the direction of ZClasses, and at best, fill in most of the gaps that ZClasses currently fill haphazardly. (In contrast to some other voices at zope corp, i *do* see significant value in ZClasses, as opposed to filesystem products[*]. I've used them in the tracker, a bit in my wiki projects, and in customer projects. So i'm with you in wanting what they offer, and in wanting relief from their shortcomings.) Many fundamentals of the component architecture were born in the CMF. Those of us using the CMF found that several of its features enabled the kinds of things we sought from ZClasses, but in a better organized way. Skins, for instance, provide for through-the-web customization of presentation and steering, as do ZClasses. In conjunction with the types-tool and type factory information, you can connect skin methods (and others) with content types, as ZClasses associate the contained method artifacts with the class. In addition, skins provide a direct development path from through-the-web customization to filesystem-based artifacts, and back. The filesystem connection, alone, is a major win over ZClasses, where people suffer for lack of version control, grepping, and other amenities available to stuff based in the file-system. Fostering of separation between presentation, application, and glue between the two is another great benefit of the CMF skinning model. ZClasses can be used in this model, but many of their virtues are superceded by what's there, and they don't specifically support the separation. Yet another advantage of the component approach is that components, even the service components, are "placeful" - they can be situated anywhere in the object hierarchy. This means you can have the same service, for instance, implemented in different ways for different parts of the folder hierarchy. This is in contrast to the global scope of every ZClass. Skins are just one better-fitting CMF methodology that the content architecture will bring to all of zope. Another is the types-tool, by which methods are dynamically associated with content-types - for refining the uses of existing content types with new functionality, without having to do any application coding. It may turn out that the most profound advancement will be the specification of interfaces to hook things together - that will increase modularity in a way that can make the dream of pervasive reuse real. I may be misjudging from a less-than-thorough understanding of the architecture, or of people's ZClass desires, but i think the component model will provide a platform for doing the kinds of things you want to do with ZClasses, in a more comprehensive and manageable way than ZClasses _can_ allow. > BTW: I missed the chat. Will there be a transscript somewhere on zope.org? Should be - i'm not sure what the situation is... Ken Manheimer klm(a)zope.com ([*] Things i like and dislike about ZClasses: i like their through-the-web development access, the ability to collect various artifacts of an application together within a folderish GUI, the implicit packaging of TTW-manageable property sheets and, generally all the stuff they gather together for you. I *don't* like the separation of the artifacts from the filesystem, however, and the many foibles and bugs that make working with ZClasses too unpredictable. And i think their security provisions muddy the security equation, i just don't quite understand it...)

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FindHomes.py
by Chris Withers 05 Aug '01

05 Aug '01

Hi, Can someoen explain lines 138 to 153 of FindHomes.py to me? Is it documented anywhere? cheers, Chris

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Storing modules in the ZODB
by Joseph Barillari 05 Aug '01

05 Aug '01

Hello, I'm having trouble storing to the ZODB. The code in question reads a string argument and selects a module from the current directory that matches the string argument, importing it into the current class: class Division(Persistence.Persistent): "A collection of rounds." def __init__(self, name, type, flags = []): self.name = name self.typename = type self.rules = __import__(type) self.rounds = [] self.teams = {} self.judges = [] self.flags = flags (rest of class snipped in the interests of brevity) Here's the result of a call using the arguments ('Test', 'APDA') in Python 1.5.2 and Zope 2.4.0 Traceback (innermost last): File "<stdin>", line 1, in ? File "t3s.py", line 909, in add_division get_transaction().commit() File "/usr/lib/python1.5/ZODB/Transaction.py", line 300, in commit j.commit(o,self) File "/usr/lib/python1.5/ZODB/Connection.py", line 375, in commit dump(state) cPickle.UnpickleableError: Cannot pickle <type 'module'> objects (add_division is a function that creates the division and stores it to a global database; essentially, a wrapper.) I tried the native cPickle module in Python 2.1.1 (to ensure that I had a clean version). Same problem -- it chokes on module objects. The purpose of this code is to enable the user to select from several different sets of 'rules' ('APDA' is currently the only one written), which are implemented as Python modules. At run-time, when a 'division' is created, the ruleset is imported into the object instance as self Do you have any suggestions as to how I might implement this? Thanks, Joe

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XML-RPC and Exceptions
by Tobias Oberstein 05 Aug '01

05 Aug '01

lets say i call some method of an zope object via xml-rpc and * give wrong parameters or * throw an exception within the method for example. then the result served by zope will be a html page describing the error, not an XML-RPC fault response like the spec describes it. how can i change this behaviour ? greets, tobias

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ATTN: Zope Security Alert
by Chris McDonough 04 Aug '01

04 Aug '01

A new Zope hotfix has been issued which addresses an important security issue that affects Zope version 2.3.3, all Zope 2.4.0 alpha and beta releases, as well as the final release of Zope 2.4.0. We *highly* recommend that any Zope site running Zope 2.3.3, Zope 2.4.0 final or any alpha or beta version of 2.4.0 have this hotfix product installed to mitigate the issue. Zope 2.4.1 will contain a fix for the issue, at which time the hotfix can be removed. Zope versions prior to 2.3.3 are not affected by this issue. Thanks to Ron Bickers for providing a reproducible test case For more information, see: http://www.zope.org/Products/Zope/Hotfix_2001-08-04/README.txt http://www.zope.org/Products/Zope/Hotfix_2001-08-04/Hotfix_2001_08_04.tgz ---------- Chris McDonough Zope Corporation http://www.zope.org http://www.zope.com """ Killing hundreds of birds with thousands of stones """

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Catalog Query Feature Request, was: RE: [Zope-dev] An idea for Un iqueValuesFor
by sean.upton＠uniontrib.com 04 Aug '01

04 Aug '01

I could definitely see the value of a unique-values query into ZCatalog, especially for creating things using <dtml-tree> using keywords, etc... On a slightly related (well, not really) note, CatalogQuery looks like it would solve a lot of problems I have had with a very Catalog-intensive application. One thought I had - I might suggest the possibility of adding a fuzzy matching operator to CatalogQuery that performs the function of wrapping wildcard searches on search terms for Text Indexes, supposing the Catalog is using a globbing vocabulary: ~= as an operator would mean an approximate (substring) match So a search for 'title ~= "engineer"' would perform a search for '*engineer*' and return results containing words like engineer, engineers, engineering, etc. Right now, I attempt to safely rewrite REQUEST['someFieldThatIamSearching'] with a Python class method that uses a zillion re.sub() calls to wrap search terms in * characters; I wonder if there is a way to alternately implement something like this at a lower level, perhaps in CatalogQuery; I get the feeling it would be quicker and much more simple. If something like that were implemented as well as some equivalent to sort_on, I'd stop pulling my hair out with traditional workarounds and definitely switch all my stuff to use CatalogQuery instead... Thoughts? Sean -----Original Message----- From: Casey Duncan [mailto:cduncan@kaivo.com] Sent: Monday, July 30, 2001 8:20 AM To: Chris Withers Cc: zope-dev(a)zope.org; Anthony Baxter Subject: Re: [Zope-dev] An idea for UniqueValuesFor Chris Withers wrote: > > Casey Duncan wrote: > > > > possibly, yes. I'll look to add this to my CatalogQuery product. I > > believe the btrees can be pressed into service here... > > Hadn't heard of this CatalogQuery product... where can I find out more? > > I think I may have been about to develop something similar, so maybe we can help > each otehr out? > > cheers, > > Chris > http://www.zope.org/Members/Kaivo/CatalogQuery This is my first stab at this. I forsee a much more general query mechanism in the future, but this works better than the stock stuff (for me) and it works today! Let me know what your ideas are... -- | Casey Duncan | Kaivo, Inc. | cduncan(a)kaivo.com `------------------> _______________________________________________ Zope-Dev maillist - Zope-Dev(a)zope.org http://lists.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope )

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An idea for UniqueValuesFor
by Chris Withers 04 Aug '01

04 Aug '01

I quite often need to do something like: results = MyCatalog(meta_type='Person',continent='Africa').uniqueValuesFor('FirstName') ...which would give you the minimal list of firstnames of people who live in Africa. A bit contrived but I seem to bump into lots of real world cases where I need to do similar. What I currently have to do is the brutal and slow approach of "walk through the results" :-S But Anthony came up with a great suggestion: > What would make more sense (maybe?) is > results = > MyCatalog(meta_type='Person',continent='Africa',uniqueValuesFor='FirstName') What do other people think? Is there a nice fast way of implementing this? cheers, Chris

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can you import a Product into a python script ?
by Simon Michael 03 Aug '01

03 Aug '01

Python scripts are super-cool.. except I can never do what I want. Safety, shmafety. Am I right in thinking the following can't work ? ## Script (Python) "zwiki_tests" ##bind container=container ##bind context=context ##bind namespace= ##bind script=script ##bind subpath=traverse_subpath ##parameters= ##title= ## # run ZWiki test suite via simple through-the-web test runner from Products import ZWiki return ZWiki.tests.run()

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Re: [Zope-dev] Help on Zope security needed ...
by Oliver Bleutgen 03 Aug '01

03 Aug '01

Just resending to zope-dev, silly me adressed zope at first... Hi, just to give a little more weight to that... > > The funny thing is: http://.../ROOT/FOLDER/title will work fine ... > Indeed, funny. Should probably not happen. Are you > sure, you get the "title" form root and not that from "FOLDER" > (it has a "title" of its own). Just tested it with blank zope 2.3.3 / method - testfolder - userfolder with user test and manager role (just in testfolder!) The following doesn't work for user test: http://localhost/method/manage The following _will_ work for user test: http://localhost/testfolder/method/manage and let's me change method, which is contained in zopes root. Hmm, this shouldn't be so, should it? cheers, olier

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Security still wierd
by Michael R. Bernstein 03 Aug '01

03 Aug '01

I have a Python Product that I have mostly finished, and now I want to add security to it. I am importing Globals.InitializeCLass and AccessControl.ClassSecurityInfo. I am adding a ClassSecurityInfo instance in my class, and I am calling InitializeClass on my class at the bottom of the Module. I have run into the following problem: Classes in Python products that inherit from OFS.SimpleItem.SimpleItem or OFS.SimpleItem.Item have an attribute set: __allow_access_to_unprotected_subobjects__ = 1 This allows all class attributes and subobjects that are not explicitly private or protected by a permission to be accessed from the restricted code environment, or directly traversed into by a web browser. Supposedly, setting __allow_access_to_unprotected_subobjects__ = 0 inside your class will return the behaviour to the default (access not explicitly allowed is denied), but this doesn't seem to work for me. Adding explicit permissions to methods *does* work, but only for methods. Attributes such as dictionaries would be left unprotected. Can anyone suggest what I might be doing wrong? I am working with Zope 2.4 Thanks, Michael Bernstein.

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