February 2001 - Zope

Q: ZPoPy and transactions again, with postgresql.
by Gilles Lavaux 16 Feb '01

16 Feb '01

Hello all, (NB:Axel.Missbach has asked the same thing some days ago) Sorry if it's a well_documented_somewhere/stupid question, that's my problem: I want to update a database, several tables, in one http call. I use DTML+Zsql methods, several of them during this update. How can I put theses actions inside one transaction? I use ZPopyDA+ postgresql I would appreciate an answer to this. I think it's a 'basic' problem on a www+DB system, and that it's very easily solved if you use a perl-DBI cgi. But with Zope I was unable to find a hint in the documentation/mailing list. Is it possible to do all the work inside an external method using directly the PoPy library and using the commit/rollback?? Thanks for any help Gilles Lavaux

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RE: [Zope] Including remote html-pages on a Zope server (with extracting of the title and body of the remote page)
by Pieter Biemond 16 Feb '01

16 Feb '01

Max Møller Rasmussen wrote: > >a) has anybody done something like this before? > Yes ... it's evil evil evil. > > Getting an external page ans howing the content is simple. I have > an product > that does this. But all the url's need to be converted to absolute url's. > And then you only got one page working. Why should I convert URL's to absolute ones? Because of the fact that it's an intranet most links are relative. Relative links should just work fine in my setup. I will urge our contributors not to use absolute URL's like "http://oldserver/somepage.html" but will ask them to use "/somepage.html" instead. That should work on both "http://oldserver/somepage.html" as well as "http://zope/somepage.html. Can you send your product (or the name of the product you used). > If you want to be able to browse an external site through you zope pages, > It's a whole different ballgame again. I'm not interested in converting (absolute) URL's/HREF's in the document. Regards, Pieter

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re:[Zope] MySQL, PostgreSQL, etc
by Richard Moon 16 Feb '01

16 Feb '01

> >Message: 9 >Reply-To: <donald.braman(a)yale.edu> >From: "Donald Braman" <donald.braman(a)yale.edu> >To: <zope(a)zope.org> >Date: Wed, 14 Feb 2001 14:08:53 -0500 >Subject: [Zope] MySQL, PostgreSQL, etc. > >Hello! > >I'm in a situation that I'm sure many are familiar with...choosing between >MySQL or PostgreSQL. My main goals are stability under high load and ease of >use. I don't need transactions. I know the standard comparison: MySQL is >faster, simpler, and more popular, while PostgreSQL is slower but is more >fully SQL standards based, handles transactions, etc. Are these generally >accurate descriptions? Stability under load - seems to favour PostgreSQL . Ease of Use - not quite sure what you mean by that, but the features available in PostgreSQL make it easier to code SQL that does what you want it to. Features such as Unions and Subqueries help you get at your data easily, features such as Views, Triggers and Stored Procedures are used to make databases consistent and secure - which I guess makes them easier to use ! I've seen lots of discussions on this topic and the answer you get seems to depend entirely on the person you ask. If you ask someone with experience of developing large apps using commercial databases they will say PostgreSQL. They find it amazing that anyone would contemplate serious database development without Unions, Subqueries, Views, Triggers and Stored Procedures. It's like going back ten years. Having said that the lack of OUTER (LEFT) joins in PostgreSQL is a pain, though of course there's a workaround If you ask a web-developer then the apparent speed gain of MySQL apparently overrides all other considerations. However the latest release of PostgreSQL (7.1) appears to actually outperform MySQL, particularly in a high-load situation where inserts are being done on-line (MySQL's lack of row-level locking appears to be the problem here). Take a look at this comparison http://www.phpbuilder.com/columns/tim20001112.php3 I developed a Zope-based project using PostgreSQL originally but I migrated it to MySQL because my host providers (those excellent people at NIP) were only supporting MySQL. Since my project (www.tunedb.org) didn't have any transactions involving money or real things (like stock) then the loss of transactions was not a major problem. Of course all limitations _can_ be worked around and I found workarounds for the missing Unions and Subqueries though it was a real pain. The 7. 1 release of PostgreSQL seems to address the performance issue so I can't see any reason to use MySQL if you have a free choice. >I'm wondering what people who have used either (or both!) think about using >these (or other databases) in conjunction with Zope. Are there any special >cases where one or the other works better or worse with Zope? In terms of use with Zope - I found no practical difference. Both work extremely well. The only issue I had with MySQL is that I developed my application using the latest available version at the time, then implemented it at NIP on a slightly earlier release and I found a couple of important differences to the product. If you are looking for external hosting make sure you use the same version as your external hosts - MySQL in particular seems to introduce major changes in minor releases. When I migrated I often had to workaround the limitations of MySQL so I left the ZSQL Method code there and used a variable to hold the type of database being used. So, where there is a difference I have <dtml-if "dbtype=='mysql'"> Mysql code <dtml-else> Postgres code </dtml-if> so that I can generate the correct SQL depending on the database being used. I don't know of a way to change the database connection programmatically, so to actually make the change you would have to go and change all the connections in all the ZSQL Method - not a huge task. Richard Moon

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Best method to track session.
by Juan Carlos Coruña 16 Feb '01

16 Feb '01

Hi all! I have a site with LoginManager installed. All user must authentificate. How can I track sessions? Must I install CoreSessionTracking or is there any better way to do this?

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Zope + Postgresql = poor performance
by Felipe Alvarez Harnecker 16 Feb '01

16 Feb '01

Hi Zopistas, I'm having extremely poor performance with zope 2.1.6 postgresql 7.0.2 pygresqlda 0.3rjr2 actualy zope create just one connection to postgres, so when postgres is executing one query all the rest are queued. Just image the mess So, can one tell me where to look at ? Upgrading zope is a no no at the moment. Please reply directly cause i'm not on the list. Thanx. -- ______________________________________________________ Felipe Alvarez Harnecker. QlSoftware. Tels. 665.99.41 - 09.874.60.17 e-mail: felipe.alvarez(a)qlsoft.cl http://qlsoft.cl/ http://ql.cl/ ______________________________________________________

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<Folder instance at 67f918> ???
by Lee Reilly CS1997 16 Feb '01

16 Feb '01

I'm having a problem passing in a list (as a string) to a Python method... I am creating a list called 'weights' as follows: <dtml-call "REQUEST.set('weights',[])"> <dtml-in "REQUEST.form.items()"> <dtml-if expr="_['sequence-key'] in ('classcode','tablename', 'practicals', 'tutorials', 'assignments', 'bonus')"> <dtml-else> <dtml-call "weights.append(_['sequence-key'] + 'x' + _['sequence-item'])"> </dtml-if> </dtml-in> When I pass this to a Python method and simply return the value of weights like: <dtml-var expr="obtainResults(_.this, `weights`)"> <Folder instance at 67f918> appears in the page (well, in the HTML source) instead of the actual value of weights. Where am I going wrong? displaying <dtml-var weights> gives me: ['b2x5', 'b1x4', 'p9x2', 'p8x3', 'p5x2', 'p4x3', 'p7x2', 'p6x3', 'p1x2', 'p3x2', 'p2x3'] so that's okay. Can anyone offer me any advice? Thanks very much in advance, Lee

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Re: [Zope] Translator Product
by Federico Di Gregorio 16 Feb '01

16 Feb '01

Scavenging the mail folder uncovered Paolo Comitini's letter: > > Im using Zope 2.2.5 and the Translator Product... > But I'm running into troubles. I found no > way of doing the following > > http://www.website.com/FH1/index_html > finding > http://www.website.com/de/FH1/index_html or > http://www.website.com/en/FH1/index_html the Translator does not descend a folder hierarchy. trnslated objects should be placed in a flat hierarchy inside the language folders. do as follows: http://www.website.com/FH1/Translator http://www.website.com/FH1/Translator/en/index_html http://www.website.com/FH1/Translator/de/index_html then <dtml-with FH1> <dtml-lvar index_thml> </dtml-with> will work. ciao, federico -- Federico Di Gregorio MIXAD LIVE Chief of Research & Technology fog(a)mixadlive.com Debian GNU/Linux Developer & Italian Press Contact fog(a)debian.org The number of the beast: vi vi vi. -- Delexa Jones

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extensions (.html .gif), security, and multilanguage sites
by CARL ROBERT BLESIUS 16 Feb '01

16 Feb '01

Hello! We are creating free internet based public health resource, which will be module based and tailored, covering a wide range of diseases. The first will be a skin cancer module. I am really excited about Zope, it seems to be just what the doctor ordered (no pun intended). Some general Zope beginner questions: - file extensions... will we have problems programming with python if we use extensions (e.g. index.html melanoma.jpg) in Zope 2.3 or is there a way around it? We do not want to confuse users (index_html!?). - the sites we are building will be multilingual (e.g. titles in 4 languages) what is the best way to deal with this (we want to use the templating power of Zope => Language of content determines template)? A ZClass with customized DTML Documents and DTML Methods which have special properties? The properties that come to mind at the moment are: - Language - Template (According to branch of site and language) - Author - Author email - Publish (Yes or No) One concern for example is the multilingualism of breadcrumbs and site maps (we want them to be dynamically generated). -Security - any tips on security? When using the tree function for example how do I prevent certain folders from being listed? What is important when running zope as far as security goes? Where do I watch for security problems with zope? Anyone have good ideas or experience? Please any tips would be greatly appreciated. Carl Blesius www.dermis.net and www.med.uni-heidelberg.de cblesius(a)ix.urz.uni-heidelberg.de P.S. Are there any qualified Zopitistas out there who would be willing to answer questions like the ones above and provide some practical suggestions (We need some experienced help at the start of our project to help with some concrete problems and this mailing list is to big to ask questions on a regular basis)? If so please contact me: cblesius(a)ix.urz.uni-heidelberg.de and I will provide some more detailed information.

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Avoiding AttributeErrors in SkinScript
by Itai Tavor 16 Feb '01

16 Feb '01

Hi, I have the following SkinScript (greatly simplified): WITH Parties.getPersonForEmail(self.id) COMPUTE party=RESULT WITH self.party COMPUTE member_id=email If getPersonForEmail returns None, the second clause returns AttributeError: party. If I change the first clause to party=RESULT or '', I can change the second to: WITH (self.party is not '') and self.party.email or '' COMPUTE member_id=RESULT But this is both ugly and bad - in the real script I have many clauses using party, so repeating this nonsense in all of them is very wasteful, and also it would be better if party is set to None when a Person is not found. But if party is set to None, the DataSkin considers it to be undefined, so I can't do WITH (self.party is not _.None)... Is there any nicer way of preventing AttributeErrors in clauses that try to access an attribute that was set to None? TIA, Itai -- -- Itai Tavor -- "Je sautille, donc je suis." -- itai(a)optusnet.com.au -- - Kermit the Frog -- -- 'Supposing a tree fell down, Pooh, when we were underneath it?' -- -- 'Supposing it didn't,' said Pooh after careful thought. --

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performance problem
by Torsten Gallmeister 16 Feb '01

16 Feb '01

hello, could anybody help? Have a perforemance prob. The DB (Data.fs) size is 25 MB. If using ZOPE "normal" the process will be around 35 MB. Ok. Have sopme pdf documents in the presentation. I reduced the DB size with the LocalFS Product. After a search-engine scan over my site the process grows up to 100 MB and more.... The server slows down. ...and there will be some doc's more in future. My question: is there a way to keep the process-size a little smaller? Thanks, Torsten.

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