September 1999 - Zope

RE: [Zope] Zope vs. Microsoft Dev Days 99 - mini-report
by Jeffrey Shell 16 Sep '99

16 Sep '99

> However, the idea of seperating "business logic" from "presentation" > sounds good. Presumably Python methods represent "business logic" > and dtml methods are the presentation layer. Making it easier to use > "external procedures" might be a big win (no flames on PythonMethods > vs. External Methods, ok). ASP's and COM components aren't editable through the web in the same way that DTML Methods and Friends are, and therefor aren't exposed to the same security risks. (And we all know that Microsoft is the queen of good security. *Coff!* :-). But granted Microsoft also has fairly decent development tools and enough kludgy server-side extensions (frontpage extensions, their hack of WebDAV) that may ease this somewhat. Having DTML Methods as the main way of scripting being open through the web interface, it can become a little too easy to expect to do everything in this situation. In essence, Zope Products are to Zope what COM components are to MS. Products are full Python classes that support an interface to be published through the web and also accessed through DTML Scripting, as well as behaving to the Zope security model. Granted writing a Product is not as easy as writing some DTML Methods, or even External Methods; but writing a COM object isn't a cakewalk either. But again, MS has the development tools and dancing paperclips and wizards to supposedly help the developer. ZClasses, when used with External Methods or subclassing from disk based Products, are another good way of seperating business logic. Business Logic, being as important as it is, is not something I would want to write in DTML, and probably not even in PythonMethods due to security restrictions. Basically if you're looking for similarity between Zope and ASP/COM in this aspect, ASP Pages are basically scripting COM objects. DTML Scripting is basically scripting Zope objects, which are in the form of the basic Products (DTML Methods, Documents, Folders (ie <dtml-call "SomeFolder.manage_changeProperties(foo='bar')">)), ZClass Instances, etc. But also remember that ASP/COM doesn't have Acquisition, web-object traversal, ZODB, Zope Security, the through-the-web near-total-management-without-requiring-ActiveX-or-Java, or other things that Zopers take for granted. These features give Zope a lot of power, but also present some interesting challenges in that they're quite a bit different way of thinking than most models that we may be used to. And...we don't have an IDE that wraps up the development and deployment of Products and External Methods. My suspicion is that Microsoft makes this sort of deployment (through the use of all those darn Wizards) a bit easier. Submissions in this area are welcomed.

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RE: [Zope] The logic of the _ variable (Q1959)
by Jeffrey Shell 16 Sep '99

16 Sep '99

> Here's some basics, to the best of my understanding: > > <dtml-var x> and <dtml-var "_['x']"> should always be > identical, and should > render 'x'. If 'x' is a function or method, it will be > called. You can > also spell this <dtml-var "_.getitem('x', 1)"> In some ways right. <dtml-var expr="_.render(_['x'])"> looks in the current Document Template namespace for a variable named 'x' and renders it fully. There's a fair amount of magic to the use of <dtml-var x> (aka <dtml-var name="x">) if x is a DTML Document/Method that you would otherwise have to get at with <dtml-var expr="x(_,_.None)">. <dtml-var expr="_['x']"> does not automatically call a function/method. It mearly looks up the object with the id of 'x' out of the _ namespace.

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Reminder: Python Conference papers due soon!
by Guido van Rossum 16 Sep '99

16 Sep '99

The deadline for paper submissions for the next Python conference is nearing! Make sure that if you are considering submitting a paper, the program chair sees your paper by SEPTEMBER 30. Papers can be on any Python, JPython or Zope related subject. Papers will be reviewed and the best papers will be selected for presentation. You will hear about selection by October 22. For more information, see the official call for papers: http://www.python.org/workshops/2000-01/cfp.html ** We are planning a significant Zope presence at this conference! ** The conference will be held from January 24-27 in Alexandria, VA (just across the Potomac from DC). Make Python the first conference in the new millennium you visit! For more info, see the conference home page: http://www.python.org/workshops/2000-01/ Send all email questions about papers to: ipc8papers(a)cs.uchicago.edu --Guido van Rossum (home page: http://www.python.org/~guido/) (And sorry for the broad spamming.)

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New to ZClass Questions
by Albert Kinderman 16 Sep '99

16 Sep '99

I am setting up a site for faculty committees on my campus. I have just started using ZClasses with 2.0.0. I set up a memberProduct so that the content managers can add members to each of the committees. So far so good. (I'm glad Amos is rewriting the tutorial - things change fast around Zope!). I then created an agendaProduct (and will create a similar minutesProduct). agendaClass is a folder, i.e. the Base classes include ZClass_for_folder and ZObjectManager. I also created an index_html method for the agendaClass. The index_html is intended to hold the actual agenda in html to be displayed when the agenda instance is viewed. When I create an instance, say sept16-1999, the instance contains the index_html which displays correctly, but it cannot be managed (and has no actual content) since index_html does not show up in the contents of sept16-1999. 1) What do I need to do to get index_html to appear in the contents of the instance? 2) When the instance is created, the creator is asked for an id and a date. I would also like to have the "text" box for the index_html contents displayed with the choice of direct editing or a "browse" button for uploading a local file. In that manner, the content manager can add the agenda all on one page, creating the instance of the agenda "folder" and the contents of its index_html at the same time. Is it possible? Thanks. Al P.S. When I created the memberClass (also a "folder"), I did not use ZObjectManager as a base class, and all the views were automatically included. When I created the agendaClass, I included ZObjectManager, and the views had to be added one at a time. Feature or Bug? -- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Albert Kinderman California State University, Northridge albert.kinderman(a)csun.edu Department of Managment Science

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RE: [Zope] can't find that thread that justifies a '-' in variabl e names
by Jeffrey Shell 16 Sep '99

16 Sep '99

> I'm gonna do a demo/class on Zope for my team at work next week. My > dtml is so full of _['sequence-item'] that I think I am bound to be > asked about it. DTML was designed more as a reporting 'language' initially. In the old days of Bobo when there was significantly less through-the-web editing, putting code in DTML in the form of expressions was not done. DTML was a way of making a "view" of an object and seperating code from presentation. A very powerful part of all this was (and still is) the batch processing features of the dtml-in tag, which included all sorts of features for dealing with batches as well as other sorts of reporting on a sequence of objects (totals, medians, etc). Since there was no worry about having to access these special variables (sequence-item, sequence-number, previous-batch-start-var-whatever), it was a non issue. The variables being named this way were probably easier to read and easier to type (meaning Jim didn't have to go through the agony of using his shift key too much :) than using an underscore -- especially some of the really long names that can come out of the batch stuff (a really really cool feature I encourage people to learn more about. It seems woefully neglected. It's a feature you don't get as easily in the script/html hybrids of ASP and PHP). As Principia started to grow up and more and more work was done through the web into what we now know as DTML Methods, the need to "script" became increasingly apparent. Thus, DTML Scripting (via Expr's) was born. It was obvious that these special names would be a problem, hence the introduction of the namespace now known as _. (In the early revisions of the Expr machinery it was known as _vars). At least, that's how I remember it. There's a fair amount of baggage we still carry around from the old Bobo days -- but be grateful. If Bobo wasn't so great to begin with, Zope wouldn't be nearly as cool as it is :).

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RE: [Zope] Still having problems w/Zope install
by Michel Pelletier 16 Sep '99

16 Sep '99

-----Original Message----- > From: Wayne Spivak [mailto:WSpivak@sbanetweb.com] > Sent: Thursday, September 16, 1999 8:49 AM > To: zope(a)zope.org > Subject: [Zope] Still having problems w/Zope install > > After compiling python w/threads & parse & sha on the FreeBSD > 3.2-Release > machine.... > > > ./../Components/zlib/zlib.c: In function `PyZlib_compress': > ./../Components/zlib/zlib.c:61: warning: assignment from incompatible > pointer type This isn't a problem. > AttributeError: compile The only thing that could cause this error is not having the parser module. Are you sure you're using the right Python? Make absolutely sure that the python your compiled is the same as the one Zope uses, and try and run it: [michel@korak python]$ python1.5.2 Python 1.5.2 (#1, Jul 5 1999, 14:47:37) [GCC egcs-2.91.66 19990314/Linux (egcs- on linux2 Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam Py$ import parser If this fails, you don't have the parser module. -Michel

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RE: [Zope] can't find that thread that justifies a '-' in variabl e names
by Michel Pelletier 16 Sep '99

16 Sep '99

> -----Original Message----- > From: Roman Milner [mailto:rmilner@dev.tivoli.com] > Sent: Thursday, September 16, 1999 1:17 PM > To: zope(a)zope.org > Subject: [Zope] can't find that thread that justifies a '-' > in variable > names > > I'm gonna do a demo/class on Zope for my team at work next week. My > dtml is so full of _['sequence-item'] that I think I am bound to be > asked about it. The reasons are hysterical, I mean historical. Expression evaluation was added after the first few revisions of DocumentTemplates. Your welcome to submit a patch that causes DTML to accept 'sequence_item'. > I think I remember a thread on the list where somebody from DC > explained why they chose dashes - but I can't find it. (Is it just me > or is that egroups search lame?) It was chosen because at the time it was a non-issue. -Michel

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can't find that thread that justifies a '-' in variable names
by Roman Milner 16 Sep '99

16 Sep '99

I'm gonna do a demo/class on Zope for my team at work next week. My dtml is so full of _['sequence-item'] that I think I am bound to be asked about it. I think I remember a thread on the list where somebody from DC explained why they chose dashes - but I can't find it. (Is it just me or is that egroups search lame?) Anyway, does anyone have a pointer to this? Thanks, ^Roman -- If I ate spinach I'ld be called Spinach D. - Mike D ------------------------------------------- Roman Milner rmilner(a)dev.tivoli.com

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More ZMySQLDA troubleshooting w/ Zope 2.0.0
by ben andrew fulton 16 Sep '99

16 Sep '99

OK, so I figured out what it is that the interface doesn't seem to like about my queries. First, a recap of the general error and traceback: --- Error, exceptions.KeyError: unhandled SQL used: select sessioncode from users limit 10 Traceback (innermost last): File /usr/local/dc/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 214, in publish_module File /usr/local/dc/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 179, in publish File /usr/local/dc/Zope-2.0.0/lib/python/Zope/__init__.py, line 201, in zpublisher_exception_hook (Object: test_auction_listing) File /usr/local/dc/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 165, in publish File /usr/local/dc/Zope-2.0.0/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: manage_test) File /usr/local/dc/Zope-2.0.0/lib/python/ZPublisher/Publish.py, line 102, in call_object (Object: manage_test) File /usr/local/dc/Zope-2.0.0/lib/python/Shared/DC/ZRDB/DA.py, line 316, in manage_test (Object: test_auction_listing) File /usr/local/dc/Zope-2.0.0/lib/python/Shared/DC/ZRDB/DA.py, line 297, in manage_test (Object: test_auction_listing) File /usr/local/dc/Zope-2.0.0/lib/python/Shared/DC/ZRDB/DA.py, line 401, in __call__ (Object: test_auction_listing) File lib/python/Products/ZMySQLDA/db.py, line 191, in query KeyError: (see above) --- After some trial and error, I discovered that db.py is apparently bombing on columns of type bigint and mediumint. "sessioncode" in the above example is a bigint column type, and if I select a char, decimal, or smallint column instead, the query runs fine (although an unsigned smallint will come back with an "L" appended to each number). I'm now using MySQL version 3.22.25-log after upgrading my Debian installation to unstable for the hell of it. Any idea what might be causing this problem, and if there's a workaround I can implement in my query? Will the MySQL db interface for Python that was just released into beta handle this situation better? Thanks, I hope I'm closing in on a solution, -->ben

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in-tag problems
by Alexander Schad 16 Sep '99

16 Sep '99

Hi ! I'm using the in-tag to iterate over a data set. I have used the following variables to navigate through the data:     That worked fine ! Till now :( For some reason it's not working on three of our servers. The variables give wrong results and as a result the created links lead to wrong entries. I'm using : Zope 1.10.2 (source release, python 1.5.1, linux2), on Python 1.5.2 (#4, Jul 26 1999, 16:56:10) [GCC 2.7.2.1] on linux2 Here's the whole relevant source:  <a href="query_start=">(last  entries)</a>   <a href="query_start=">(next  entries)</a>  Any help would be appreciated, Bye, Alex

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