June 2002 - Zope-Dev

Problem testing CatalogAware class
by Vincenzo Di Somma 07 Jun '02

07 Jun '02

Hi all, does someone knows about problems testing CatalogAware subclasses ? I have unit tests for my class and work well, but if I subclass also from CatalogAware I receive: File "/usr/lib/zope/lib/python/OFS/ObjectManager.py", line 267, in _setObject object.manage_afterAdd(object, self) File "/usr/lib/zope/lib/python/Products/ZCatalog/CatalogAwareness.py", line 42, in manage_afterAdd self.index_object() File "/usr/lib/zope/lib/python/Products/ZCatalog/CatalogAwareness.py", line 112, in index_object getattr(self, self.default_catalog).catalog_object(self, self.url()) File "/usr/lib/zope/lib/python/Products/ZCatalog/CatalogAwareness.py", line 85, in url else: url=self.absolute_url() File "/usr/lib/zope/lib/python/OFS/Traversable.py", line 48, in absolute_url return join([req['SERVER_URL']] + req._script + path, '/') KeyError: SERVER_URL Suggestions? Thanks, Vincenzo. -- Vincenzo Di Somma - Responsabile Ricerca e Sviluppo - Icube S.r.l. Sede: Via Ridolfi 15 - 56124 Pisa (PI), Italia E-mail: e.disomma(a)icube.it WWW: www.icube.it Tel: (+39) 050 97 02 07 Fax: (+39) 050 31 36 588

2 1

DAV collections, index_html, and HEAD
by Karl Anderson 07 Jun '02

07 Jun '02

Objects that inherit from Folder (and therefore from Collection) and also have an index_html that's a Python method (or othewise nonvanilla, presumably) return a 405 (Method Not Allowed) for HTTP HEAD requests. Zope 2.5.1 raises on line 57 of Collection.py. The object raises if its index_html member doesn't have a HEAD attribute. Surely it's a bug to only give HEAD for objects that return an index_html via hasattr/getattr. What about getitem, __bobo_traverse__, and __call__? Shouldn't we find the object to HEAD via ZPublisher? And aren't we bypassing the access control checks, anyway? Would it be a good idea to try and make up a HEAD response for arbitrary attributes that don't support it (such as Python methods)? Perhaps by publishing them internally, and picking whatever we can from RESPONSE, computing Content-Length from the returned stream if necessary? It's inefficient, but at least it's cache-friendly... and better for tools (er, linbot) that assume that if it can't be found via HEAD, it isn't there. Excerpt from Collection.HEAD(): # Note that we are willing to acquire the default document # here because what we really care about is whether doing # a GET on this collection / would yield a 200 response. if hasattr(self, 'index_html'): if hasattr(self.index_html, 'HEAD'): return self.index_html.HEAD(REQUEST, RESPONSE) raise 'Method Not Allowed', ( 'Method not supported for this resource.' ) raise 'Not Found', 'The requested resource does not exist.' persephone ~/tmp= telnet viii.dclxvi.org 80 Trying 206.163.69.253... Connected to viii.dclxvi.org. Escape character is '^]'. HEAD /blog HTTP/1.0 HEAD /blog HTTP/1.0 HTTP/1.1 405 Method Not Allowed Date: Thu, 06 Jun 2002 02:22:40 GMT Server: Apache/1.3.12 (Unix) mod_ssl/2.6.6 OpenSSL/0.9.5a Bobo-Exception-File: /usr/local/zope/2-5-1/lib/python/webdav/Collection.py Bobo-Exception-Line: 57 Bobo-Exception-Type: Method Not Allowed Bobo-Exception-Value: bobo exception Connection: close Content-Location: http://viii.dclxvi.org/blog/ Ms-Author-Via: DAV X-Powered-By: Zope (www.zope.org) Python (www.python.org) Content-Length: 2106 Content-Type: text/html -- Karl Anderson kra(a)monkey.org http://www.monkey.org/~kra/

2 1

Testing Zope Products with Python Debugger
by William Trenker 06 Jun '02

06 Jun '02

I've read the various tutorials and have successfully used Zope with the Python debugger. But, of course, I can't have my production Zope running and the debugger running at the same time unless I get Zeo going. But is there another way? Is it possible to start Zope in the debugger but have it open a different data.fs file for testing? (I only have one computer and have to keep a small, Zope-driven web site running 24/7 as well as do development on a new Zope Database Adapter.) I've looked into the Zeo How-To and feel a little overwhelmed. And I suspect it is probably asking a bit too much of one Celeron 400 with Windows 98 to have all that running. What do you think? (Sorry, but "get Linux" or "get another computer" would be great, but aren't on my immediate horizon.) Thanks, Bill ---------- "The commandments of the LORD are right, bringing joy to the heart. The commands of the LORD are clear, giving insight to life . . . For this is the love of God, that we keep His commandments. And His commandments are not burdensome." (Psalm 19:8, 1John 5:3) <http://torahteacher.com/>torahteacher.com --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com) Version: 6.0.363 / Virus Database: 201 - Release Date: 5/21/02

6 5

multiple monkeypatches
by Jim Penny 06 Jun '02

06 Jun '02

Is there a safe way to handle multiple monkeypatches? Here is the problem. External editor monkeypatches ObjectManager.manage_main. There are some other products that also need to monkeypatch this object. For example, if Jerome Alet's Zshell were turned into a python product, it would be natural for it to monkeypatch this same object. But, if it does so, whichever monkeypatch is applied last will destroy the previous. Any ideas on a reasonably simple way to solve this problem. Thanks Jim Penny

5 9

re: First call to external method after restart fails
by Emile van Sebille 06 Jun '02

06 Jun '02

I found this post from Ted Skolnick but saw no follow-ups, and I am having the same problems. Ted, did you get this resolved? > I have an external method that takes 3 params. After I restart Zope ( > running on Linux ), I get the following error on my first call... > > Error Type: TypeError > Error Value: rmlToPDF() takes at least 3 arguments (0 given) > > All subsequent calls work fine (i.e. a refresh in my browser, and no more > error, my external method works ). I restart Zope as root. Anyone ever > see this before? I just upgraded an account from 2.4.x to 2.5 binary on linux. -- Emile van Sebille emile(a)fenx.com ---------

3 3

Re: [Zope-Coders] ACTION: 2.6 project status updates...
by Lennart Regebro 05 Jun '02

05 Jun '02

From: "Brian Lloyd" <brian(a)zope.com> > I suggest we leave this one deferred then, as I really > would like any changes to the security architecture to > be strongly informed by Zope3 work. I'm pretty sure it *is* informed, to be honest. :-)

3 3

DirectoryViews for Zope2.6?
by kapil thangavelu 05 Jun '02

05 Jun '02

hi folks, i was wondering if there is interest (or possiblity) of including directory views in zope2.6. i've been using them for team development with zope, and i've come to think their a fantastic dev. method in combination with cvs. any takers? cheers kapil

2 2

Refresh makes all imported modules = None
by Lennart Regebro 04 Jun '02

04 Jun '02

Suddenly when I refresh products it seems that all imported modules in the refreshed product are set to None, because after a refresh, anything I try to do always ends up with an error message like "None has no attribute foobar" or "None is not callable", and this always happend when I try to access something that is imported. Has anybody seen this? Zope 2.5.1/Python 2.1.3 Best Regards Lennart Regebro Torped Strategi och Kommunikation AB

7 9

putting the 'two' back in tpc
by Leonardo Rochael Almeida 04 Jun '02

04 Jun '02

In a chat with Kapil at #zope we came to the conclusion that most Zope database adaptors don't really implement two phase commit, because they make no effort, during the 'vote' phase (the first phase of the tpc) to make sure that the commit will go thru without errors. For example, if you have the following schema in postgresql: CREATE TABLE "passwd" ( "username" character varying(64) UNIQUE, "password" character varying(64) NOT NULL, "roles" character varying(255), Constraint "passwd_pkey" Primary Key ("username") ); CREATE TABLE "userproperties" ( "username" character varying(64) NOT NULL references "passwd" (username) DEFERABLE INITIALLY DEFERRED, "propname" character varying(128) NOT NULL, "value" text NOT NULL, ); This schema allows an entry in the 'userproperties' table to exist without an equivalent user in the 'passwd' table before the end of the transaction. If, on commit, there still isn't a user with the same 'username' on the 'passwd' column, postgres will raise an error and won't let the commit go thru. Now all the current DA implementations that I know of call the database commit only in the second (or finish) phase of the tpc, which will result in a locked down Zope, as Zope is not very much fond of people bailing on him on the second phase. Now the correct solution for this, as far as postgres is concerned, is to execute the query, 'SET CONSTRAINTS ALL IMMEDIATE' in the 'vote' phase, since no other query will be executed between this query and the commit. Postgresql will raise an error while trying to execute this query if any coinstraint is yet to be satisfied, so Zope will be able to cancel the transaction to all those registered in the transaction machinery. And if the postgresql documentation is correct, 'SET CONSTRAINTS...' is an SQL92 and SQL99 standard, so other db's might be able to benefit from this. The problem is that lib/python/Shared/DC/ZRDB/TM.py doesn't provide a _vote() slot which should be called by tpc_vote(). TM documentation should mention that this slot should be overriden, just like _finish() and _abort(). It should also mention why this slot should be overriden ("consistency this, consistency that, yadda yadda.."). The nazi bastard in me wants the default implementation of this slot to raise an error to remind people to override it. If your DA doesn't need, or can't, implement a _vote() for some reason, you should explicitly override it to do nothing. However I know that breaking other people's DA is not nice :-) The not so nazi bastard in me says that the default _vote() implementation should zLOG a warning about '_vote()' not being implemented, but I know that even this might be too much to ask, since logfiles everywhere would go crazy. Anyway, this may be a little late, but I believe that implementing a do-nothing _vote() that is called by TM.tpc_vote() is a small and unintrusive change but a change that is important enough to deserve to be included in 2.6, so that DA authors take notice and implement it where possible. I'd volunteer to make this change myself if my commiter's agreement had been commited (I'm looking at you Paul Everitt). I know that I'll bug the Psycopg guys once this change is thru. Leo -- Ideas don't stay in some minds very long because they don't like solitary confinement.

2 1

[Zope] PDF generation from products methods
by Thierry Florac 04 Jun '02

04 Jun '02

Hi... I've found, in http://www.zope.org/Members/mjablonski/howtoPDF, a way to produce PDF documents from Zope basic HTML outputs. But what I'd like to do is to be able to produce PDF documents from any HTML output, including : - output generated by forms requests, - output generated by any product method Any idea ?? Thanks, Thierry

2 1