[Zope-dev] Re: Re: Refresh and debugging product creation issues.....
Shane and Zope-Dev users of Refresh, Have you noticed any differences refreshing objects that are in the root folder versus higher in the Zope tree? Last week, I was debugging a class using Refresh. I had two class instances, E1 in the root directory and E2 which lived inside E1 (my class is folderish). Trying http://localhost:8080/E1/test and http://localhost:8080/E1/E2/test gave completely different results after changing the class's python code and refreshing. E2 picked up the new class definition while E1 kept the old class definition. Aggressively flushing the cache a few times and refreshing again sometimes fixed the problem, but only temporarily. E1 would use the new code a couple of times then inexplicably switch back to the old code. Needless to say, this bamboozled me completely! Today I am debugging the class instances one level higher in the Zope tree (http://localhost:8080/demo/E1/test and http://localhost:8080/demo/E1/E2/test). Refresh works perfectly. I don't need to flush the cashe or anything like that. Also, the reported size of the cache after a full refresh is down to 8 objects (it was around 28 before). Strange huh? Does this mean that Zope's cache hangs on much more tightly to objects in the ZODB root that inside folders? Cheers, Stephen - Original Message - From: "Shane Hathaway" [EMAIL PROTECTED] Newsgroups: digicool.zope.dev To: "Stephen Simmons" [EMAIL PROTECTED] Sent: Tuesday, October 10, 2000 3:53 PM Subject: Re: [Zope-dev] Re: Refresh and debugging product creation issues. Stephen Simmons wrote: The combination of Shane's Refresh product and Steve's code to prevent multiple names in the product add list is really useful. Thanks, guys! I've reworked Steve's initialize code so it works for products that have multiple classes. As an added benefit, you no longer need to specify which class is being refreshed, so the meta types can be renamed or the code reused without changing a single line. This is great, Steve and Stephen. I'll get this worked into Refresh right away. Shane _______ Stephen Simmons, [EMAIL PROTECTED] HealthArena B.V., Amsterdam, The Netherlands phone +31 20 486 0555; mobile +31 6 1505 3086; fax +31 20 486 0559 ___ Zope-Dev maillist - [EMAIL PROTECTED] 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 )
[Zope-dev] Inconsistent behaviour in Zope's constructor security check?
I have just concluded an epic two day struggle with Zope's security
machinery. I think I've won, and wanted to find out whether anyone else has
had similar problems.
I had defined a Python product that worked very nicely. I was able
to add and delete my objects and edit, copy and export them perfectly well.
But when I tried to rename, paste or import them, I got an exception saying
that "The object X does not support this operation".
It appears that security checks for permission to add an object to a
Folder is done differently by the Product Add machinery and the CopySupport
machinery that paste/rename/import use.
I had defined my constructors slightly unconventionally in
__init__.py. Redefining the constructors more normally solved my immediate
problem, but it doesn't remove the source of Zope's inconsistent behaviour.
More details of the diagnosis are at the end of this email, for those who
are interested.
Is this something I should put in the collector?
One happy result of this mess is that I am now on a first-name basis with
about 80% of the Zope source code!
Stephen
_______
Stephen Simmons, [EMAIL PROTECTED]
HealthArena B.V., Amsterdam, The Netherlands
phone +31 20 486 0555; mobile +31 6 1505 3086; fax +31 20 486 0559
Problem copying/pasting and renaming
I was able to create new instances of my Element class, but whenever I tried
to rename, cut/paste or import the objects, _verifyObjectPaste() in
CopySupport.py raised a Copy Error (The object X does not support this
operation).
_verifyObjectPaste() performs three checks:
(i) The container is happy having an object of this type being pasted into
it
(ii) The user is allowed to create new objects of this type
(iii) The user is able to access the object being pasted or renamed
All three conditions were true, so there is no reason why renaming, etc
should be prevented. Especially when I could create objects as desired
through the management screens.
Solution
The problem was traced to the unusual way I had defined the constructors in
__init__.py and the class's module. It appears that
getSecurityManager().validateValue(meth) does not exactly duplicate the
check done when adding a product instance.
Originally, I removed the constructor definition tuple from __init__.py:
def initialize(context):
"""Register Element"""
context.registerClass(
PlatformElement.Element,
constructors = (PlatformElement.Element), # Specified indirectly!
icon = element.gif
)
and put it at the end of my class definition module, PlatformElement.py:
class Element(Folder):
...
def manage_addElement(self, id, name='', title='', REQUEST=None):
"""Create an Element"""
...
Element_constructors = (
('manage_addElementForm', HTMLFile('Element_add', globals())),
('manage_addElement', manage_addElement),
)
In this case, check (ii) was failing at line 390 of CopySupport.py when
trying to validate the constructor
manage_addProduct/HAPlatform/manage_addElementForm.
The problem was fixed by changing the constructor definition to the more
conventional form:
In __init__.py:
def initialize(context):
"""Register Element"""
context.registerClass(
PlatformElement.Element,
constructors = ( # Specify constructors explicitly!
PlatformElement.manage_addElementForm,
PlatformElement.manage_addElement,
),
icon = element.gif
)
In PlatformElement.py:
...
manage_addElementForm = HTMLFile('Element_add', globals())
def manage_addElement(self, id, name='', title='', REQUEST=None):
"""Create an Element"""
...
While this fixes the problem, it leaves unresolved the question of why
Zope's security machinery was happy using the original constructors but
barfed when checking whether it could use them.
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[Zope-dev] Help, please!!! __call__ problems with DTML templates
Today is not a good day:-( I've just spent 2 days trying to force
__call__ to render my product properly, got every error possible at least
seven times, and wasted last night working out what was wrong with Refresh
(I was calling refresh on the wrong product. Duh!).
Please, please, please, can someone point me in the right direction.
I have a class called Element which has three components:
1. purpose: a string describing the element's role (rendered as structured
text)
2. template: a string that is rendered to display the element (DTML)
3. Element inherits from Folder so it can contain sub-elements which can be
included in the template
For example, suppose A is an element that contains a sub-element B (i.e. B
is A.B)
Ahas template 'Element A contains dtml-var B'
and purpose 'Contain B'
Bhas template 'element B, which contains nix'
and purpose 'Element with no subelement'
Now for the tricky bit: "dtml-var A" needs to be rendered one of three
possible ways depending on a variable in the REQUEST. So __call__ needs to
return one of
- case a: the purpose property (as structured text) wrapped in []
- case b: render the template, with sub-elements properly rendered
- case c: render the template, with sub-elements wrapped in [] showing
their purpose
Then 'dtml-var A' must be rendered in the three cases as:
- case a: '[Contain B]'
- case b: 'Element A contains element B, which contains nix'
- case c: 'Element A contains [Element with no subelement]'
To do this, I need to write my own __call__ method since __call__ is what
detemines how objects gets rendered in DTML (is this correct?)
def __call__(self, client=None, REQUEST={}, RESPONSE=None, **kw):
With this, I discovered that 'dtml-var A' gives client=None and REQUEST={}
while
'dtml-var "A(_,REQUEST)"' gets client=_ and REQUEST=REQUEST.
But I cannot for the life of me, work out how to do what I need. In
particular:
1.) How do you magically get the DTML context from 'dtml-var A' without
having to resort to 'dtml-var "A(_,REQUEST)"' in the templates?
In the __call__ methods of different classes, I've seen some code like:
'if REQUEST is None and not kw: REQUEST=self.REQUEST' (from
Catalog.py)
and other code like
'if hasattr(self, 'aq_explicit'): bself=self.aq_explicit else:
bself=self' and
'security=getSecurityManager() security.addContext(self)'
(from DTMLDocument.py)
I can't see any consistency in what these classes are doing, so I don't know
what I need to do.
2.) How to convert an arbitrary text string into rendered DTML inside a
python product method?
How do you get the object's properties, REQUEST and acquisition context all
in the namespace?
I've been trying code like:
template = 'span class="purpose"dtml-var purpose
fmt="structured_text"/span'
dtml = HTML(template, globals())
rendered = dtml(self, REQUEST)
but this doesn't work. All the example classes I've seen (such as
ZWikiPage.py in ZWiki) use DTMLDocument as their base class so can call
DTMLDocument's __call__ on themselves as in
text = apply(DTMLDocument.__call__,(self, client, REQUEST, RESPONSE),
kw)(ZWikiPage.py, line 135)
This doesn't help me because I don't have DTMLDocument as a base class.
Looking through the source for DTMLMethod etc is not very clear because lots
of "apply(__call__,(...),kw)" calls are all mixed up with acquisition code.
3.) Do I need to write a custom tag (dtml-element A) to get this
behaviour?
So, if anyone out in Zope land can help me, I'll be eternally grateful. I've
exhausted my patience looking through the NIP mailing list archives, the
How-Tos and the Zope site and need to have something to demonstrate on
Thursday.
Thanks in advace,
Stephen
P.S. ChrisW, searching NIP for "__call__" returns every message with 'call'
in it, which is not quite the same thing!
___
Stephen Simmons
HealthArena B.V.
phone +31 20 486 0555
mobile +31 6 1505 3086
[EMAIL PROTECTED]
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