February 2000 - Zope

Zope Weekly News
by Mike Pelletier 23 Feb '00

23 Feb '00

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 * Neuberger & Hughes have announced the release of version 1.0 of their WorldPilot software. It has been whispered in shady corners of conferences that WorldPilot could well be Zope's first Killer App. WorldPilot is an integrated, through-the-web PIM and IMAP mail client, with collaborative capabilities. http://lists.zope.org/pipermail/zope-announce/2000-February/000117.html New Products * Software Product: "Simple Directory of URLs", submitted by "Roug" This handy product manages sets of links to external resources. It can perform click-through counting, and allows untrusted users to submit link suggestions (which are subject to review). http://www.zope.org/Members/Roug/SimpleURLs * Software Product: "An Extensible, Base Banner System", submitted by "Bill" "Bill" wrote, "BannerSystem is the beginning of a full-fledged banner add management system. Currently, it is functional, and includes a sample implementation that can be used." http://www.zope.org/Members/Bill/Products/BannerSystem * Software Product: "JSplitter", submitted by "brianh" This is a replacement for ZCatalog's word-splitter. This product enables full-text searching of Japanese with ZCatalog. http://www.zope.org/Members/brianh/JSplitter * Software Product: "A simple site mapping object", submitted by "haqa" This ZClass product provides three forms of navigation widgets: "Top Level" (horizontal), "Full Context" (vertical) and a full Site Map. It requires "lalo"'s Renderable ZClass product. (See links) http://www.zope.org/Members/haqa/ZSiteMap http://www.zope.org/Members/lalo/Renderable-ZClass * Software Product: "A simple photo album product", submitted by "haqa" A simple ZClass product which provides a means of organising and browsing collections of images. They can be browsed as thumbnails in user-configured batch sizes. http://www.zope.org/Members/haqa/ZPhotoAlbum Updates * Software Product: "MySQL user folder", submitted by "vladap" Version 0.4.0 has been released. This release adds a layer of indirection to the DTML interface files the user folder uses to allow for multilingualism. Also, anonymous authentication now works. http://www.zope.org/Members/vladap/mysqlUserFolder * Software Product: "An Interface for MySQL", submitted by "adustman" This Products description states, "MySQLdb is a Python interface to MySQL-3.22. It is designed to be fully thread-safe and will not block other threads." A patch is included which will update ZMySQLDA to use this interface, rather than it's older, non-thread-safe version. The latest release is 0.1.2. http://www.zope.org/Members/adustman/MySQLdb Zope.org items * How-To: "Using Zope on a third-party web host", submitted by "gldnspud" This How-To explains how to set up Zope to run on a Unix server where you do not have administrative rights, such as on an ISP's server. http://www.zope.org/Members/gldnspud/zope3rdparty * How-To: "Use Direct Traversal of SQL Methods", submitted by Chris McDonough 'Direct Traversal' is a trick which allows you to create URLs which pass arguments to SQL Methods _without_ a query string on the end of the URL. This allows more aesthetically pleasing, "Mom-friendly" URLs. The audience for this How-To appears to be Zope newbies and intermediates with some SQL experience. http://www.zope.org/Members/mcdonc/HowTos/direct_traversal -- Mike Pelletier.

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sequence-key usage
by Jim Sanford 23 Feb '00

23 Feb '00

Does anyone know how sequence-key should/can be used within a dtml-in construct? Jim Sanford snafford(a)bellsouth.net

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Re: [Zope] Calculations - more dumb questions.
by Tres Seaver 23 Feb '00

23 Feb '00

Richard Moon <richard(a)dcs.co.uk> writes: > > I was reading earlier postings about 'variables' or the lack of them in > Zope and I went off and investigated Python Methods and External Methods > and I've got them working ... but .. I can't figure out how to use them to > solve my problem ... > > I have an SQL method and I've generated the form and results report using > the standard wizard - absolutely wonderful. > > Let's say I have an input variable, called 'customer' on the form which is > passed to the SQL method. BUT I want to intercept that variable and do > something with it, let's keep it simple and say that I want to put the > string "CT" in front of what the user enters (I know that's trivial but for > the sake of argument). > > I can write an External Method or Python Method which does the necessary > but it returns the string back to the calling object as text which is > displayed by the browser. > > Can anyone tell me how to get that new string back into the variable > 'customer'. > > Please :-) Ok, say your form is in a DTML Method called "gather_criteria". Make its ACTION attribute point to another DTML Method, "prepare_query". Inside prepare_query, munge the value of customer and call the SQL method, 'query_db':: <dtml-call "REQUEST.set( 'customer', 'CT' + customer )"> <dtml-in query_db>  </dtml-in> If the munging is more complicated, then write a Python method, "munge_customer_id", which takes the user-supplied value returns the munged value:: return "%08d" % _.int( customer ) # pad with leading zeroes to 8 digits Then call the munge_customer_id inside prepare_query:: <dtml-call "REQUEST.set( 'customer', munge_customer_id( customer ) )"> HTH, Tres. -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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Re: [Zope] Zope hanging on a dereference???
by Tres Seaver 23 Feb '00

23 Feb '00

Michiel Toneman <toneman(a)phil.uu.nl> asks: > > This came up on the list some time ago, but this > solution gets Zope (2.1.4) in an infinite loop. > > -------------------------------------------------------------- > <dtml-in "objectIds()"> > <dtml-let refID=sequence-item>  > <dtml-with "_[ refID ]">  > <dtml-var id>  > </dtml-with> > </dtml-let> > </dtml-in> > -------------------------------------------------------------- > > Any ideas? Um, why go there? I mean, I don't know what is bothering Zope, but there are easier ways to get what you want::  <dtml-in "objectValues()"> <a href="&dtml-absolute_url;"> <dtml-var id> </a> </dtml-in> or, if you really just want the ids:: <dtml-in "objectIds()"> <dtml-var sequence-item> </dtml-var> -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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Re: [Zope] Scalability
by Tres Seaver 23 Feb '00

23 Feb '00

Lucas Vogel <lvogel(a)exponent.com> asked: > > Where can I read the documentation on zope's scalability? I really love > Zope, and I want to see how far it can go... > > (sorry for being vague, I've spent all night planning a website to use zope > for) The topic has come up rather frequently on the list. The best strategy to get the overview you are looking for is to download the list archives (http://lists.zope.org/pipermail/zope and http://lists.zope.org/pipermail/zope-dev; look for the "Gzip'd Text" links) and browse them with grep or some such. -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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Re: [Zope] Accessing Subobjects of a ZClass Instance
by Tres Seaver 23 Feb '00

23 Feb '00

Nico Grubert <nico(a)beehive.de> writes: > > I created a ZClass containing > -Base Classes both "Object Manager" and "Catalog Aware" > -Subobjects both "Image" and "File". > > In a DTML-Methode all properties of an instance are shown by: > <dtml-in "PARENTS[0].objectValues(['MyProduct'])"> > <tr> > <td><dtml-var myObjNr></td> > <td><dtml-var myObjTitle></td> > .... > > "myObjNr" is the id of each object. > > Some Objects contain a file or an image or both a file and an image. > I upload two images "beach.gif" and "water.gif" to the instance e.g. > "MyObj01". > the tag <img src="<dtml-var myObjNr>/beach.gif"> > this works fine and shows me the image "beach.gif". > What I need to do that I can see all images or even better the whole > content an instance contains ? > Something like ???? > syntax: > <img src="<dtml-var myObjNr>/___content of an instance______"> A DTML Method like the following shows all images contained within a Folder (or within a "folderish" ZClass instance like yours):: <dtml-in "objectValues( 'Image' )"> <dtml-var sequence-item> </dtml-in> -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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Re: [Zope] aquisition and refining
by Tres Seaver 23 Feb '00

23 Feb '00

Alex Burton <burton(a)w3cast.com> wrote: > > Me again (last one for tonight!) > > Aquisition is groovy, but is it possible to refine aquired > properties instead of redefining them from scratch? > > (Creating a standard_html_header in s subfolder and using <dtml-var > standard_html_header> does not produce expected result, that is > grabbing the upper-level's definition of standard_html_header). > > Is there a DTML tag such as <dtml-refine> which, when stated at a > given level, would indicate where to insert sublevel redefinition of > the DTML method? > > Maybe i'm thinking too much of OO inheritance... "Jonothan Farr" <jfarr(a)real.com> replied: > > You know, I've never really gotten this either. Maybe Jim Fulton could explain > for us one more time or else point us at a good explanation of -why- > acquisition begins at the root and goes down the tree instead of starting at > the current level and going up, which I believe is what pretty much everyone > expects it to do when they first run across it. The slides from Jim Fulton's "Acquisition Algebra" talk are online: http://www.zope.org/Members/jim/Info/IPC8/AcquisitionAlgebra/index.html I know the title is intimidating, but I think the talk was "satori-making". Tres. -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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Re: [Zope] CatalogAware
by Tres Seaver 23 Feb '00

23 Feb '00

Tom Deprez <tom.deprez(a)uz.kuleuven.ac.be> wrote: > > I've a problem which I can't solve. > > I made a small ZClass and has CatalogAware as base class. > > However, when I add an instance of this ZClass in a folder, and when I've a > ZCatalog (id: TestCatalog) then this instance isn't added in the list of > 'TestCatalog'. I thought that a CatalogAware Class just could do this... > > a) Am I missing here something? > b) I'm not quite sure, but is this adding to a Catolog done automatically > or do you have to specify somewhere in which catalog instance (here > TestCatalog) the object has to be listed? How can I do this? "Loren Stafford" <lstaffor(a)dynalogic.com> replied: > > If you have a non-default catalog ID, you have to do something special in > the manage_add method. It's documented in the How-To on creating a > catalog-aware Zclass. http://www.zope.org/Members/AlexR/CatalogAware CatalogAware instances expect to find and register themselves with a ZCatalog object named "Catalog". If you want them to use a catalog with a different name, you can either: * Modify their class' MyClass_add method to switch them (as described by the HowTo Loren points to). or: * Attach a "proxy" DTML/Python/External Method named "Catalog" which hijacks the lookup to your desired location. I have a How-To describing this technique at: http://www.zope.org/Members/tseaver/inherit_ZCatalog -- ========================================================= Tres Seaver tseaver(a)palladion.com 713-523-6582 Palladion Software http://www.palladion.com

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zodb lock
by Garrett G. Hodgson 23 Feb '00

23 Feb '00

i've been trying, with minor success, to figure out how to use ZODB. i've now got a little app that uses a FileStorage db to store Person objects, where a Person has just a name and an age. it works the first time i run it, but subsequent times i get: Traceback (innermost last): File "./TestPersistence.py", line 29, in ? print GetPeople() File "./TestPersistence.py", line 16, in GetPeople app = TryPersistence.App() File "./TryPersistence.py", line 27, in __init__ self.db = ZODB.DB( ZODB.FileStorage.FileStorage( file ) ) File "/usr/local/src/Zope-2.1.3-src/lib/python/ZODB/FileStorage.py", line 262, in __init__ lock_file(f) File "/usr/local/src/Zope-2.1.3-src/lib/python/ZODB/lock_file.py", line 101, in lock_file raise error, ( ZODB.POSException.StorageSystemError: Could not lock the database file. There must be another process that has opened the file. i assume i'm missing some cleanup or finalization, beyond get_transaction().commit() any ideas? (i didn't post the code because it seemed overly lengthy for this question. i can post it if that'd help.) thanks -- Garry Hodgson Every night garry(a)sage.att.com a child is born Software Innovation Services is a Holy Night. AT&T Labs - Sophia Lyon Fahs

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Missing ZClasses?
by Lucas Vogel 23 Feb '00

23 Feb '00

I apologize for the blatant newbie question here, but I was following the documentation trying to create a ZClass, and unless I'm mistaken I don't have a ZClass in my list of objects to create. Is this a product that I have to download first? It doesn't sound right, but if it is where is it because it's not on the list? Also, I downloaded the ZPhotoAlbum-1.0 product to install into zope as well. I copied the .zexp file into my import directory, but it errors out when I try to import it. Is this because of my ZClass problem? Thanks ------------------------------------------- Lucas Vogel, Software Developer Exponent Failure Analysis Associates, Inc. lvogel(a)exponent.com (623)587-6739

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