- Zope-Dev - Zope lists

"dynamic permissions" in zope
by Heinz-Josef Claes 02 Jan '01

02 Jan '01

Hi, I'm very new to zope and have to eximine, if it's usable for our requirements. The question I have, is very simple or perhaps very difficult, I don't know. Our requrements are a permissioning system which depends on a matrix: There are two independend qualities which describe, if a user is allowed to see a document. This can be displayed in a matrix. Only if *both* qualities match, the user is allowed to see it. As far as I understand zope, it is not possible to map this directly (as by all other systems I know). So my question: Is it possible to connect a permission (or role) in zope with a method (instead of a static flag which was set)? If it is possible, it should be possible to call a special algorithm with this request, which can implement whatever is needed. So, it would be (easy) possible to *integrate* this functionality. (I called this permissions "dynamic", because the are evaluated when requestet.) Or does anybody has another (better) idea? Any help is very apreciated, Heinz-Josef Claes hjclaes(a)web.de

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Re: [Zope-dev] ZPatterns example update....
by Itai Tavor 02 Jan '01

02 Jan '01

Steve Spicklemire wrote: >Hi Folks, > > The Dumb ZPatterns example is updated. Now there is some more >realistic object referencing going on, borrowing of code snippets >between Specialists and suchlike. There is also more in the way of >reasonable documentation, though everything is in flux, and it still >doesn't resemble a truly completed product. I just feel the need to >get things finished enough that I can stop thinking about them for a >while. ;-) In particular there the ToDos now hold references to Doer >and Deliverable, and no 'lists' are maintained. One thing I need to do >is to have these references automatically 'fixed' when a 'referred to' >entity is removed or modified in such a way that the link should be >broken.... that's for the next version. If I'm not careful.. it won't >be a 'simple' example anymore. There's got to be a line here somewhere >(in the sand?). Nice work, Steve. Removing id lists looks good. I started building objects using getXForY(y_id), but the last one I made used an id list following the Dumb Example. I've just changed it to use getXForY, and it's much cleaner, plus it makes adding X from Y/editInstanceForm easier. I like the idea of naming all UI methods with '_html' - now, if you find yourself referencing a method which doesn't end in '_html' in your html code, you know you need to add an interface method. I just need to decide if I like it enough to change all my existing code... Some thoughts about the broken links handling problem: If an object depends on the existence of another (for example, if you wanted a ToDo to be tightly linked to a Deliverable) then it should be deleted when the Deliverable is deleted, right? You'd have WHEN OBJECT DELETED CALL ToDos.deleteInstances(myToDoIDs) in the Deliverable SkinScript, and you would never have ToDos floating around without a Deliverable. As for the Deliverable changing and invalidating the link, I think it would be solved if you used immutable ids for all objects, and stored the Deliverable title in a separate property. In case of weaker links, such as between ToDo and Doer, I guess it should be ToDo's responsibility to return None if the Doer referenced by doerID doesn't exist - treating it the same way as the case where no doer has been assigned. Maybe with this SkinScript: WITH Doers.getItem(self.doerID) CALCULATE self.doerID=RESULT.id or '' ? But I'm not really sure about this... I think you've managed very well to stay on the right side of the line in the sand... the problem is that complex real world applications have a lot of stuff on the other side of the line, and the challenge is to pull that stuff over the line. My personal problem is figuring out if the stuff I have on the wrong side of the line is necessitated by the complexity of the application, or if I'm just making things unnecessarily complicated... Itai -- Itai Tavor "Je sautille, donc je suis." C3Works itai(a)c3works.com - Kermit the Frog "If you haven't got your health, you haven't got anything"

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Re: [Zope-dev] ZCatalog catalog_object
by Chris Withers 02 Jan '01

02 Jan '01

Itamar Shtull-Trauring wrote: > > Chris Withers wrote: > > > ...in which case, I wonder why CatalogAwareness goes to the trouble of > > unindexing and then re-indexing? > > Because in older ZCatalog (before 2.3 and maybe before 2.2.4), > catalog_object did not uncatalog automatically. When in doubt, assume > ZCatalog is broken :p Hmmm... I wonder if Chris P or anyone else in the know could confirm the recommended steps to recatalog an object? cheers, Chris

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aq_inContextOf attribute error
by Alex V Koval 02 Jan '01

02 Jan '01

Hello All ! After installing latest stable version of Zope (2.2.4) I tried to install ZFormulator version 0.2. And as result got 2 problems with permissions system. First was in ZFormulator itself, and was corrected: __roles__ = ('manager',) was changed to __roles__ = ('Manager',) but this bug correction worked fine for previous versions of Zope, and in current version adding of field produced error: Attribute Error: aq_inContextOf in line 231 of lib/python/AccessControl/User.py I am nor Zope nor Python hacker, but I tried to correct this line a little, and this worked for me. Please advice did I made it correct way or not. User.py line 231: ---------------- Here was the original code (which produced error): if not parent.aq_inContextOf(self.aq_parent.aq_parent,1): Here is replacement (added check is attribute exists): if hasattr(parent, 'aq_inContextOf') and not parent.aq_inContextOf(self.aq_parent.aq_parent,1): After this correction everything works fine, but since I am not Zope/Python guru, but just a user which wanted some program to start working, I keeping changed locally, but of course I am interested was this correction OK. Regards. -- Alex V. Koval

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What's 'section' in blocks[0] in block dtml tag?
by LEE Kwan Soo 02 Jan '01

02 Jan '01

Hi. I'm playing/struggling to make a custom block dtml tag. Let me call it, dtml-quote tag. dtml-quote tag is similar to dtml-comment tag except it will emit html_quoted, not rendered version of what lies between <dtml-quote> ... </dtml-quote>. (I feel it will be usefull when I show & write some dtml examples on my korean zope site). After seeing around some python sources, I finally got that tname is the name of the tag, args is args, and section is something, in the following code. def __init__(self, blocks): tname, args, section = blocks[0] and section seems to have 6 attributes/methods: '__name__', '_v_blocks', '_v_cooked', '_vars', 'blocks', 'globals', 'raw' But that mistic raw is null string, '' and blocks is no help for me. How can I retrieve the raw source string enclosed in a block tag pair? LEE Kwan Soo. ps. My English is evem more cryptic this morning. Sorry I've sat up alnight play Kingdom Under Fire.

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Re: [Zope-dev] PythonScripts
by Dieter Maurer 01 Jan '01

01 Jan '01

Dieter Maurer writes: > I looked at ZopeCVS's PythonScripts. > I mostly like it -- with the following exceptions: > > * Namespace binding > > It does not yet work, apparently: > .... Sorry! This was my fault: I had update my Zope CVS version but not yet recompiled the shared objects. Dieter

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UNEXPECTED: Acquisition.Explicit may acquire implicitly
by Dieter Maurer 31 Dec '00

31 Dec '00

While trying to understand, what the "bself= self.aq_explicit" in "OFS.DTMLMethod.__call__" should do, I detected an unexpected behaviour: usually, this "bself" acquires implicitly from its container (though not from its context) More precisely: if "bself.aq_self" is itself an implicit acquisition wrapper, the "bself.aq_explicit" acquires implicitly from "bself.aq_self.aq_parent". The following Python module demonstrates the behaviour: ------------------------------------------------------- from Acquisition import Implicit class C(Implicit): pass b= C() b.i= 0 b.d= C() b.h= C() e_bd= b.d.aq_explicit try: e_bd.i print 'e_bd implicitly acquired i' except AttributeError: pass e_bhd= b.h.d.aq_explicit try: e_bhd.i print 'e_bhd implicitly acquired i' except AttributeError: pass ------------------------------------------------------- At first, I thought this were a bug. At second thought, however, it appears to be quite natural, though unexpected: if o is self.__of__(parent), then getattr(o.aq_explicit,k) = getattr(self,k).__of__(o) If "self" is an implicit wrapper itself, then acquisition may be used to look up "k". This implies, that the idiom <dtml-if "_.hasattr(o.aq_explicit,XXXX)"> cannot be used safely to test, whether "o" has attribute XXXX itself (rather than acquired it). We probably should have a standard function for this kind of test. Dieter

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Re: [Zope-dev] DTML Documents == DTML Methods that are anchored?
by Dieter Maurer 30 Dec '00

30 Dec '00

The Doctor What writes: > What are the differences between DTML Documents and Methods > internally? There are too small differences: 1. DTML documents implement the "PropertyManager" interface, i.e. they can have properties other than "id" and "title". 2. DTML documents place themselves on top of the DTML namespace when they are rendered (called), DTML methods do not place themselves on the namespace at all for rendering. The effect is that during name lookup a DTML Document is asked early whether it (or its acquisition ancestors) can satisfy the name request. If it can, you get this object. A DTML Method, on the other hand, would not be asked in a similar situation, as it is not on the namespace stack. This means, name lookup looks through the DTML Method directly onto the method's client, the Method is completely transparent. A DTML Document is only partially transparent, it hides all names that it or its acquisition ancestors define. Only the other names are handled in the same way as would be the case for a DTML method. Dieter

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Updating a ZCatalog when objects in it change their path
by Chris Withers 30 Dec '00

30 Dec '00

Squishdot uses ZCatalog quite heavily. When you move/copy/rename a Squishdot site, all the Paths stored in its catalog become incorrect. Not nice... Darrick experienced this when copying a Squishdot site and then trying to delete a load of articles. He didn't notice the uncatalog errors he was getting when he did this and so reported that articles were still showing up in searches after he'd deleted them. That's because the paths stored didn't change when the site was moved and the delete code in squishdot was trying to delete objects with a path at their new location. Rather than rant about the fact that paths are not unique identifiers for objects in a ZODB (because they change when the objects move, and, as this demonstrates, that's not good!) I thought I'd fix the problem. However, the only way I could find to solve it was to add a manage_afterAdd method to Squishdot Sites which recatalogued all postings. This is a _lot_ more resource intensive than it needs to be, since I don't actually want to recatalog all postings (quite expensive when there are 3000+ of them ;-), I just want to modify the paths that ZCatalog has stored. Is there any way to do this? There probably should be ;-) cheers, Chris

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IMPORTANT! Zcatalog path handling changes in 2.3
by Christopher Petrilli 30 Dec '00

30 Dec '00

Gang, In order to resolve untold number of situations where the Catalog does "stupid" things and returns less than useful information, we have heavily modified the information stored in the Catalog (and generated by CatalogAware). You can read about this here: http://dev.zope.org/Wikis/DevSite/Projects/ZCatalogVirtualHostFix/ You can find a tarball that contains everything updated here: http://www.zope.org/Members/petrilli/zcatalog-pathsupdate.tgz If you untar this in the root of your Zope installation you should get a new Zcatalog that has all the new code in it. Please read and test... This is especially important for people who are using Squishdot/etc. We hope to make a full code release with 2.3a2 sometime very soon. PLEASE take a look at this, and provide feedback ASAP. Chris -- | Christopher Petrilli Digital Creations | petrilli(a)digicool.com Where Zope comes from

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