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Newbie, Please HELP !
by Olivier Deckmyn 16 Dec '99

16 Dec '99

KeyWords : Business Objects, Persistency, ZODB. Hello all, I've been playing with Zope for a few weeks now...I really like it ! The problem I have is that, given a problem, I don't know what Zope technology I should use... Here is my problem : I have designed a small object application with UML. I then have implemented it in python. Only the business rules of my application are written yet (no UI nor GUI). The whole application source is made of 3 python files (.py). Python objects are persistent and stored into a file using the shelves mechanism (that I found to be very simple and handy). I test the core of my application in the console, invoking methods of my objects. Storage is correct, etc... Now that I know that my application "could" work (=all the business rules and methods have the correct behaviour), I want to access it through the web (=make a web application). I would like to use Zope to do so. First, I can modify my existing python code (to make it compliant with any Zope mandatory things - that I don't know yet !). [1 - Dealing with the Storage of my Objects] I don't want to deal with any Relational storage directly. I would like to go on using a full object approach : to have persistent python objects. Use of OQL would be nice, but not mandatory for my first needs. At last, I don't want to have to store/retrieve my objects from a SQL database by hand...The persistent mechanism should be as easy to use and handle as the shelves one(I don't need to use shelves in particular - I just want an object-storage mechanism). There is no need for me to have access to the today-existing datas (that were store in files from the shelves mechanism). [ 2 - Dealing with the visual HTML representation of my objects ] I would like to have a strong frontier between the rendering of data (=production of HTML code) and the logic of my application (=python code that handles the life of my objects). [ 3 - Reusability - Luxe ] I would also like to be able to use the same python code in both the console and web version (not mandatory). Given this, I don't know what Zope mechanism is best for me : ZClasses ?, ZCatalog ? External method ? Other ? Should I make a product ? Where can I put my existing python code ? How will I deploy it to several sites ? How do I store my business objects into ZODB ? If I am not clear enough : you can flame me ! I will explain it again :-) Please help ! Thanx for your support. Olivier Deckmyn, Paris - France.

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Re: [Zope] (newbie)-Anyone Please Help me
by Anthony Baxter 16 Dec '99

16 Dec '99

>>> ozric wrote > -snip- > I tried the <dtml-var "methods.userid"> and that finds the userid file, but it > returns plain text unrendered. here is whats in unserid. try <dtml-var "methods.userid(REQUEST,_)">

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Re: [Zope] Multiple Zope servers?
by Hung Jung Lu 16 Dec '99

16 Dec '99

From: "Jeff K. Hoffman" <jkhoffman(a)carolina.rr.com> >... >Check out: > > http://www.digicool.com/Solutions/ZEOFactSheet.pdf > >Short story: > >Yes, you can do this with the ZEO add-on ($$) from DC. It pulls ZODB out >into a separate process, potentially running on a separate machine, which >handles all object storage for one or more Zope instances. In this way, >you can scale Zope exactly as you desire. > >--Jeff Wow, the ($$) part makes me think twice. I'd like to explore a bit more... it's a scary thought to set up a website only to find that it gets choked even with moderate hit rate. Does anyone know any simpler tricks to improve performance for the interim period, so to make things more or less scalable when going from one processor to two or three? Of course, when the website is served by 5 processors, probably ZEO would make sense. Any comments would be appreciated. regards, Hung Jung PS- perhaps the thing to do is to separate web presentation data (like DTML, etc.) from the enterprise data (user info, product catalogs, etc.), and use ZODB only for the presentation data, while using an external database for the enterprise data. This way, I could run several copies of Zope, all accessing the same database server. That is, essentially make the ZODB read-only. And ZODB is changed only when changing the whole website's presentation. I think can live with that. :) Sorry for thinking aloud... :) ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

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Re: force upper case in REQUEST
by Hung Jung Lu 16 Dec '99

16 Dec '99

Terry Kerr wrote: >... > ><dtml-call "propertysheets.subject_info.manage_changeProperties( > subject_code=<dtml-var id upper>, >... > > >This returns invalid syntax? How can I convert to upper case? You cannot embed a <dtml-...> tag inside another <dtml-...> tag. Once you are inside a <dtml-...> tag, you have to use methods provided by Zope objects. In particular, the underscore _ variable contains a number of useful methods. In your case, you would use: <dtml-call "propertysheets.subject_info.manage_changeProperties( subject_code=_.string.upper(REQUEST['id']), ...)"> hope this helps, Hung Jung ______________________________________________________ Get Your Private, Free Email at http://www.hotmail.com

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Organizing large projects
by Timothy Grant 16 Dec '99

16 Dec '99

Hi, This is probably a silly question, but here goes anyway. I am working on my first large (for money) Zope project. I have created a folder for the entire project, but have found that I am getting so many objects in the root folder to the project that it is becoming hard to manage. My first inclination is to create sub-folders for each type of object (e.g., SQLMethods and connections, forms, images, etc.) but something tells me this is not a good plan. What organizational schemes have you found that work well for you? Thanks for your input! BTW: I'm still looking for assitance on a SQL problem I posted a few days ago. -- Stand Fast, tjg. Timothy Grant tjg(a)exceptionalminds.com Chief Technology Officer www.exceptionalminds.com Red Hat Certified Engineer office (503) 246-3630 Avalon Technology Group, Inc. fax (503) 246-3124 >>>>>>>>>>Exceptional Minds, Innovative Products<<<<<<<<<<

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force upper case in REQUEST
by Terry Kerr 16 Dec '99

16 Dec '99

Hi, I want to force a property entered by a user when creating a zclass to uppercase. The _addform method for the Zclass sends a REQUEST variable 'id' to the _add method. The _add method currently does this:  <dtml-call "propertysheets.subject_info.manage_changeProperties( subject_code=REQUEST['id'], ...  But I want the subject_code property to be uppercase, so I imagine I need something like:  <dtml-call "propertysheets.subject_info.manage_changeProperties( subject_code=<dtml-var id upper>, ...  This returns invalid syntax? How can I convert to upper case?

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RE: [Zope] zope da's
by Chris Petrilli 16 Dec '99

16 Dec '99

I hope that George doesn't mind my copying the entire list, because I think he raises some philosophical issues that people probably haven't dealt with before... > chris you are correct that is what I meant. why build > DA's specifically > vs making a PDBC (python database connection)?!?! or some type of > abstraction layer. this is what john udell was talkign about > w/ unix (lack > of consistent database abstraction layer to talk w/ that DBI > provides for in > perl on unix) in one of his articles. and I think ODBC works > fine on NT and > helps speed development. In fact, Python has something called the DB-API (http://www.python.org/topics/database/DatabaseAPI-2.0.html) which provides somewhat of an abstracted interface. While this works for certain types of applications, we've found that a lot of the things we need aren't compatible with what other people want in their behaviour, and therefore we've been forced to write our own spec. This is amazingly unfortunate, but sadly necessary, especially when dealing with exception handling. Perhaps we should push more to shape the DB-API spec, but I believe Jim can speak more fully on why that hasn't been done in the past. > -> yes, i understand that the db enginers/syntax can change > in rev's- but > your SQLMethods inside of zope will break just as well if sql or sp's > change. <this is life?> If you write your SQL in such a fashion as to use (for example) comparison operators that are specific to the database you're working wtih, yes it will break. It is possible to write it in such a fashion that it won't break. This in may ways is no different than writing to the ODBC spec... > SQLMethods aren't dependant on the db your running? there > needs to be > lots of documentation on this subject matter, because I > havent run across > this. how do you keep sqlmethods 'da' independent? Because they talk via a defined API to the "Connection" object they are associated with. If you change the Connection object, then it will use a totally different database. I think this is reasonably well documented, if not, then it should be... > coding both on *nix and NT, I can honestly say that ODBC > is a huge help. > and if a ODBC driver released by Oracle are bad- what would > make digicool > being able to make these DA's and keep track w/ them. Unfortunately, ODBC is terribly incomplete when it comes to BLOB/CLOB, stored procedures, and other things that we have on the horizon. I know this because we're currently trying to unify ODBC and X/Open CLI together, and ODBC is missing many many pieces. > ->I'm sorry I was not talking specifically about JDBC but rather the > abstraction layer that JDBC is associated w/. We provide an abstraction layer, perhaps it's just not given an acronym, but let's do that: ZDBC ;-) Seriously though, it is there, there is a strong OO abstraction, and even more so on the result side of things. The fact that it's not ODBC doesn't make it less useful, especially given its origins and goals. > I would much rather see digicool manage the documentation effort and > concentrate on teh application server than spending time each > time oracle > revs on ccoming out w/ a new DA. Actually, we've written things pretty tightly and if you can find some way for us not to have to do this on ALL platforms that we support (i.e. UNIX and NT), then it's a different question, but ... unfortunately, we can't tell people to go out and buy NT because all we support is ODBC. The UNIX world does not have such an abstraction, sadly. I wish it did, it might even be more useful than ODBC is. > but that is a 1000' view and I acknowledge that. your > response also makes > me realize that I need to be much more specific in my > communications, I > apologize. Maybe I'm deeming an OS-centric layer be admin'd > and handled by > an application, zope- ODBC. and I've taken a quick poll and > no developers > here have had exceedingly large headaches w/ ODBC. But have they ever tried to support the same application on 20 different OSs? Do they use ODBC on all platforms, or just on Win32? Remember, we are *cross-platform*. I will note that competitors such as Vignette talk natively, while people like ColdFusion (which is largely a NT product) talk ODBC---and I have no idea what they do on Linux. Chris

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Zope Weekly News
by Mike Pelletier 16 Dec '99

16 Dec '99

G'day, Zope Weekly News is a digest of some of the useful and interesting events which have occurred on the various Zope mailing lists and the Zope.org site. It is published each Wednesday evening. Any opinions contained in the Zope Weekly News are those of the chronicler exclusively. Announcements * Digital Creations announced that the next generation of its Zope application server will leverage browser technology from the Mozilla project. http://www.digicool.com/News/mozilla * Python.Org announced the Redesign Python.Org Contest. The talented winner shall receive great fame and... erm... that's it, really. Have a try and have some fun. http://www.python.org/Redesign.html New Products * "slef" has released an intriguing product called ZInstaller. The objective is to enable Zope users to download and install new Zope packages from the comfort of their web browser. http://www.zope.org/Members/slef/ZInstaller Updates * Zope 2.1.1 has been released. This is a bug-fix release that includes fixes for better handling of multiple-write conflicts, undo-related problems and problems that prevented certain third-party Zope products such as Squishdot from working. For more information, see the file CHANGES.txt in the doc directory of the distribution. http://www.zope.org/Products/Zope/2.1.1/ * "4am" released an update to his Python Methods product. The present version is 0.1.7. Python Methods are, as the name implies, methods written in Python, but which live in the object database rather than on the filesystem. http://www.zope.org/Members/4am/PythonMethod * "Bill" reports that KnowledgeKit 1.6.7 has been released: "This is a minor feature upgrade. Per request, there is now a simple How-To object integrated into the KnowledgeBase portfolio. While not yet as cool as cool as Zope.org's, it is usable." http://www.zope.org/Members/Bill/Products/KnowledgeKit * Another alpha release of XML Document is out. This release fixes a number of bugs thanks to patches form diligent Zope users and added a few minor features. http://www.zope.org/Products/XMLDocument * "anthony" has submitted "yet another minor release of SQLSession". http://www.zope.org/Members/anthony/software/SQLSession/ * Jim Washington <jwashin(a)vt.edu> updated his ZRTChat product. ZRTChat provides real-time chat with an entirely HTML interface. (No java, javascript, etc.) The present version is 0.2.0. http://www.zope.org/Members/jwashin/ZRTChat * Pavlos Christoforou <pavlos(a)gaaros.msrc.sunysb.edu> has released version 0.2.0 of FSSession. FSSession manages session data (that is, per-browser data) and stores it on the filesystem. (Compare with SQLSession.) http://www.zope.org/Members/gaaros/FSSession Zope.org items * "Duncan" submitted a How-to entitled "Session data stored in URL": "This how-to describes how to use Anthony Baxter's SQLSession product in conjunction with 4am's SiteAccess product to store a session id in the URL without the need to set any cookies." http://www.zope.org/Members/Duncan/SessionURLs * "Bill" posted a new How-To: "How to delete a catlogAware object that is no longer catalogued". http://www.zope.org/Members/Bill/Documentation/CatalogBadness Notable Discussions * There is a very informative thread with the subject "Zope stability". Michel explains how to use Zope's debugger and a number of techniques for developing in safe sandboxes and synching with a production server are discussed. http://lists.zope.org/pipermail/zope/1999-December/015181.html http://lists.zope.org/pipermail/zope/1999-December/015209.html http://lists.zope.org/pipermail/zope/1999-December/015214.html http://lists.zope.org/pipermail/zope/1999-December/015240.html http://lists.zope.org/pipermail/zope/1999-December/015245.html http://lists.zope.org/pipermail/zope/1999-December/015267.html http://lists.zope.org/pipermail/zope/1999-December/015296.html http://lists.zope.org/pipermail/zope/1999-December/015301.html http://lists.zope.org/pipermail/zope/1999-December/015351.html http://lists.zope.org/pipermail/zope/1999-December/015389.html http://lists.zope.org/pipermail/zope/1999-December/015427.html * Michael A. Alderete <alderete(a)be.com> kicked off a thread called "Zope Performance Methodology?". He outlines in good detail what would be needed to produce a document about optimising Zope's performance. He goes into everything from the underlying platform to Zope tuning parameters to optimal coding practices. Numerous people write in to fill in his blanks. http://lists.zope.org/pipermail/zope/1999-December/015254.html http://lists.zope.org/pipermail/zope/1999-December/015270.html http://lists.zope.org/pipermail/zope/1999-December/015270.html http://lists.zope.org/pipermail/zope/1999-December/015278.html * Brian Lloyd discusses the future of Zope in "Zope direction and 2.2 roadmap". http://lists.zope.org/pipermail/zope/1999-December/015297.html * The ZODB and Zope objects are explored in "Philosophical question - Zope Objects vs Entities in a RDBMS". Questions raised (and answered): How well does the ZODB scale? How does the ZODB compare to traditional RDBMS for efficiency? Can I tread ZClass objects like normal Python objects? What limitations does Linux's filesystem impose, and how can I get around them? How can I make SQL results act like 'real' objects? http://lists.zope.org/pipermail/zope/1999-December/015299.html http://lists.zope.org/pipermail/zope/1999-December/015300.html http://lists.zope.org/pipermail/zope/1999-December/015359.html * Timothy Wilson <wilson(a)visi.com> asks if anyone has written an application such as a technical support department might use to track issues. A couple leads are given. http://lists.zope.org/pipermail/zope/1999-December/015317.html * "reality check" -- Occasionally becoming a religious debate, Jonothan Farr <jfarr(a)speakeasy.org> sparked off a mailstrom with forwarded comments on Zope's lack of documentation. Opposing lines are quickly drawn: Zope has the worst documentation known to mankind vs. Zope's documentation is pretty good, really. Zope is too hard vs. Zope is pretty easy, application servers are just complex. Zope needs to appeal to a wider audience vs. That's what FrontPage is for. Amongst the lively expressions of opinions, some attempt to advance the documentation cause. Members of the ZDP remind everyone that they are busily working away, and would you like to lend a hand? Also, the next generation of Zope documentation is briefly described. http://lists.zope.org/pipermail/zope/1999-December/015393.html http://lists.zope.org/pipermail/zope/1999-December/015445.html * Bruce Perens's Zope server was on the receiving end of a multiple slashdotting. He reports that it came through with flying colours. http://lists.zope.org/pipermail/zope/1999-December/015506.html -- Mike Pelletier.

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RE: [Zope] Upgrading a product
by rgines＠purina.com 15 Dec '99

15 Dec '99

>>>Good Question! The answer is with __setstate__. > <snip> >It's allways there in every persistent object, it's defined by the >Persistence class. If you have special behavior your want to add to >that, you can override it. >> Are you aware of any working examples of this in action? >Yes, the Catalog in 2.1 upgraded itself from the Catalog in 2.0: <snip> Thanks for the info. With all the power and flexibility of Zope and ZClasses, it is becoming extremely clear to me that in order to create any 'real' products, writing code in Python is going to be a must. Oh well ....

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Sorting on integers
by Albert Kinderman 15 Dec '99

15 Dec '99

I am just learning to use Zope with MySQL. One field in my database is an integer, goal. When I get a list of items from the database and sort on goal, the sorting is alphabetical (15 before 2 before 23 before 5). How do I get the sort order to reflect the order of the integers? In the dtml below, sqlgetleaders is the ZSQL method that returns the list of leaders (lastname, firstname, goal) from the database. <table> <tr> <td>Last Name</td> <td>First Name</td> <td>Goal</td> </tr> <dtml-in sqlgetleaders sort=goal> <TR> <TD> <dtml-var lastname></TD> <TD> <dtml-var firstname></TD> <TD> <dtml-var goal></TD> </TR> </table> Al -- ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Albert Kinderman California State University, Northridge albert.kinderman(a)csun.edu Department of Management Science

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