- Zope - Zope lists

Subclassing Persistent (QUEST)
by Oscar Picasso 13 Mar '00

13 Mar '00

Hi, I'm trying to make my own pyhton classes and use them with zope, so I tried to subclass the class Persistent. However, no matter what I try I get always an error like: *** Bobo-Exception-Value: (<class exceptions.ImportError at 80a9d98>, 'cannot import name Persistent') *** I have read "The (old) Product API Tutorial", "Create a Boring Product in Python" and "ZODB" HowTos but I didn't find the exact way to do it. Even reading the Persistence module doesn't enlighten me too much: it's just the license and a string. So I would appreciate if someone could give a clue about how to subclass Persistent and to which module it belong? Oscar

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Problem with Images
by Jens Gelhaar, cuiod-tec 13 Mar '00

13 Mar '00

I've got a problem with the image class. I use Zope 2.1.4 (downloaded from http://yyy.zope.org/) with Windows 98 second edition. Let me give an example: 1. I create an image object head_1 and upload an image "cat". Everything is fine. 2. I upload an other image "dog". Almost nothing happens. The image is not there. But something has changed: The size properties. What ever I do, I do not get the right picture, I will see always "cat" but always in different sizes, the size from the last uploaded picture. But that's not all. 3. I delete the image object head_1 4. Create a new one, let's say head_2 and give it an image "dog". I see dog. 5. But now, when I rename the image object from head_2 to head_1 I will get again the old picture "cat". This scenario is always the same, regardless what I do: * shutdown the database in between * clearing the undo buffer * new installation * hide the python installation dir * delete the database I played around with the lib/python/OFS/Image.py. But I experienced enough with Zope thus I know Python. What ist wrong with me or the Image class. Help Jens

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Re: [Zope] EAGAIN errors crashing ZServer Aiieeee!!!!
by Jon Prettyman 13 Mar '00

13 Mar '00

Nope. No core file. Aieeeee!!!! -Jon Michel Pelletier <michel(a)digicool.com> writes: > Does Zope leave a core file? Try 'find -name core -print' from the top > level directory. > > -Michel > > Jon Prettyman wrote: > > > > Okay, this is what I'm getting consistently when my server crashes > > under moderate load: > > > > ------ > > 2000-03-13T18:53:02 INFO(0) GUF Successful authentication for user April (http://207.241.10.50/premium/acl_users) > > ------ > > 2000-03-13T19:01:40 INFO(0) GUF Successful authentication for user thomas (http://www.nationalmortgagenews.com/premium/acl_users) > > ------ > > 2000-03-13T19:02:24 INFO(0) GUF Successful authentication for user terrydpeters (http://207.241.10.50/premium/acl_users) > > ------ > > 2000-03-13T19:03:36 ERROR(200) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Aiieee! 17065 exited with error code: 11 > > ------ > > 2000-03-13T19:03:36 INFO(0) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Houston, we have forked > > ------ > > 2000-03-13T19:03:36 INFO(0) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Hi, I just forked off a kid: 17125 > > ------ > > 2000-03-13T19:03:36 INFO(0) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Houston, we have forked > > ------ > > 2000-03-13T19:03:58 PROBLEM(100) ZServer Cannot do reverse lookup > > ------ > > 2000-03-13T19:03:58 INFO(0) ZServer Medusa (V1.13) started at Mon Mar 13 13:03:58 2000 > > Hostname: 207.241.10.50 > > Port:80 > > > > ------ > > 2000-03-13T19:03:58 INFO(0) ZServer FTP server started at Mon Mar 13 13:03:58 2000 > > Authorizer:None > > Hostname: magmar > > Port: 8021 > > > > From the debug log: > > B 144485000 2000-03-13T19:03:02 GET /nmn/images/marketplacebutton.gif > > I 144485000 2000-03-13T19:03:02 0 > > A 144485000 2000-03-13T19:03:02 304 182 > > E 144485000 2000-03-13T19:03:02 > > B 144484496 2000-03-13T19:03:09 GET /id.htm > > I 144484496 2000-03-13T19:03:09 0 > > A 144484496 2000-03-13T19:03:09 200 3740 > > E 144484496 2000-03-13T19:03:09 > > B 143155832 2000-03-13T19:03:10 GET /newsubsid.gif > > I 143155832 2000-03-13T19:03:10 0 > > A 143155832 2000-03-13T19:03:10 200 45513 > > E 143155832 2000-03-13T19:03:10 > > B 145239016 2000-03-13T19:03:14 GET /nmn/images/marketplacebutton.gif > > I 145239016 2000-03-13T19:03:14 0 > > A 145239016 2000-03-13T19:03:14 304 163 > > E 145239016 2000-03-13T19:03:14 > > B 146772968 2000-03-13T19:03:32 GET /nmn/images/afstitle.gif > > I 146772968 2000-03-13T19:03:32 0 > > A 146772968 2000-03-13T19:03:32 304 182 > > E 146772968 2000-03-13T19:03:32 > > B 139605816 2000-03-13T19:03:59 GET /nmn/images/marketplacebutton.gif > > I 139605816 2000-03-13T19:03:59 0 > > A 139605816 2000-03-13T19:04:01 304 163 > > E 139605816 2000-03-13T19:04:01 > > B 139494360 2000-03-13T19:04:07 POST /premium/acl_users/register > > I 139494360 2000-03-13T19:04:07 518 > > A 139494360 2000-03-13T19:04:10 200 8704 > > E 139494360 2000-03-13T19:04:10 > > B 139787784 2000-03-13T19:04:28 GET /nmn/images/marketplacebutton.gif > > I 139787784 2000-03-13T19:04:28 0 > > A 139787784 2000-03-13T19:04:28 304 182 > > E 139787784 2000-03-13T19:04:28 > > > > I'm running Linux 2.2.12-20, Zope 2.1.4, currently with only ZServer > > (and FTP server.) Things get even flakier when I am running with > > PCGI. > >

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Re: Missunderstanding of DTML Methods and acquisition?
by Jonothan Farr 13 Mar '00

13 Mar '00

> What I'm most confused about right now is when it is necessary to pass > the client and namespace and when you can omit it. I'm also very unclear > as to just what the 'client' is, especially since most of the examples > I've seen involve passing in None for the client. I found the source to String.__call__ (in DocumentTemplate/DT_String.py) very enlightening. This is the same __call__ method that DTMLMethod and DTMLDocument inherit. def __call__(self,client=None,mapping={},**kw): '''\ Generate a document from a document template. The document will be generated by inserting values into the format string specified when the document template was created. Values are inserted using standard python named string formats. The optional argument 'client' is used to specify a object containing values to be looked up. Values will be looked up using getattr, so inheritence of values is supported. Note that names beginning with '_' will not be looked up from the client. The optional argument, 'mapping' is used to specify a mapping object containing values to be inserted. Values to be inserted may also be specified using keyword arguments. Values will be inserted from one of several sources. The sources, in the order in which they are consulted, are: o Keyword arguments, o The 'client' argument, o The 'mapping' argument, o The keyword arguments provided when the object was created, and o The 'mapping' argument provided when the template was created. ''' You can see that __call__ with no arguments uses defaults of None and {} for client and mapping, so essentially the template has nowhere to look up attributes. This is why you must pass these explicitly. Apparently you can also pass a mapping and keywords to the constructor but I don't think this is possible from the management interface. More ZZen is to be found in DocumentTemplate/DT_Util.py. This module contains the expression evaluation machinery, as well as the code to the special namespace variable, '_'. -jfarr ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Hi! I'm a signature virus. Copy me into your .sig to join the fun! ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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RFC: Flaws in Structured text
by Alexander Staubo 13 Mar '00

13 Mar '00

I would like to outline a few problems, based on observations of real-world usage, with Structured text. Comments are appreciated. As much as I like the format, the current syntax is either too loose, or the transformation logic too dumb, resulting in text that does not come out quite as expected. There are workarounds for all such problems, but authors and editors aren't aware of them, and continually make the same mistakes over and over again. Here are a few gotchas: - Lines starting with the text number-dot (eg., "1.") are considered to be bullets. Problem: In other languages, and sometimes in English, this is a valid non-bullet introduction. In Scandinavian languages (Norwegian is the language of my country), for instance, "1." is an oft-used way of spelling "1nd" or "first" ("2." for "2nd" or "second", and so forth). My experience is that this occurs frequently. Solution: Avoid transforming such paragraphs into bullets when they occur adjacently to valid non-bullet sentences, and only apply the transformation when the number is higher than the preceding paragraph. Validate the number itself -- today you can write 43423. Something 24324. Something else and it's still transformed into <ol><li>Something<li>Something else</ol> - Lines starting with dash-space (eg., "- The") are also interpreted as bullets. Problem: As with number bullets, this clashes with non- English conventions. At least in Scandinavian languages, quotes are often given using a preceding dash. Here's an actual example, translated to English for clarity: - Pooh, said Rabbit kindly, you haven't any brain. - I know, said Pooh humbly. Solution: Make this feature optional. - Em dash sequence ("--") usage clashes with definition lists. Problem: People, including me, frequently use an ASCII form ("--") of the em dash ("-"), in the absence of this character in the 7-bit ASCII character set. (Actually, what *I* want is an en dash, which ISO provides.) This transforms into a HTML <dl></dl> list, even when the dash occurs late in the paragraph. Solution: Only transform paragraph to definition list if the dash sequence follows the first, dot-terminated sentence, like so: This is a definition term. -- and this is the definition itself. Not sure whether this is ideal. It would likely break old stx documents. Perhaps a "force literal" control character can be introduced, like the "\" token used in Python, Perl, C, etc. Note to self: There ought to be a way to transform such poor-man's dashes into en/em dashes, and quotation marks to "smart" quotation marks. - Link transformation into HTML anchors tags is poor, or at least too rigidly parsed. Problem: Some examples of links that do not work: The document (found "here":http://www.zope.org). <dtml-var "'This is a \x022link\x022:http://www.zope.org/'" fmt="structured-text">, I'd love to give cite other annoying cases I've come across, but I don't remember them. ;-) Solution: Tolerate parantheses, and accept that URLs that are terminated with end-of-line. Provide better syntax for specifying URLs, such as this: A product called Zope (http://www.zope.org) can be found on the _Zope site_ (http://www.zope.org) which would be transformed into: A product called <a href="http://www.zope.org">Zope</a> can be found on the <a href="http://www.zope.org">Zope site</a>. - Structured text code should not wrap transformed text in paragraph tags (), or should at least make this wrapping optional. Problem: I often display stx in places where a new paragraph creates unnecessary vertical padding that violates page design -- for this purpose I have been forced to write a simple External Method that removes the offending paragraph tags. IMHO, this ought to be unnecessary. Solution: Provide necessary option. - Structured text code not available to DTML. Problem: The code is only available to External Methods and products. DTML can only get at stx through dtml-var's fmt attribute. Solution: It would be swell to have an _.stx() or StructuredText() construct. -- Alexander Staubo http://alex.mop.no/ "`This must be Thursday,' said Arthur to himself, sinking low over his beer, `I never could get the hang of Thursdays.'" --Douglas Adams, _The Hitchhiker's Guide to the Galaxy_

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Upload method for a xmldocument!
by Anders Holmbech Nielsen 13 Mar '00

13 Mar '00

hi, Does anyone have a solution to, or know where I can find one to how I can upload a ordinary xml dokument to my Zope without any user interaction ? Regards ------------------------------------------------- Anders Holmbech Nielsen | Tlf: (+45) 70 22 56 00 Software Engineer | Fax: (+45) 70 22 57 00 Integrator Uniware A/S | http:/www.integrator.dk

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zope.org Members list
by alan runyan 13 Mar '00

13 Mar '00

is it me or is the Members list take FOREVER to navigate through? and why would it take so long (more than minute) to go from first page of members to the next page? it wasn't like this a few months ago. is it the load on the server?(I tried last night @4AM to the same results) is it the way its fetching and ordering members from the catalog (this definetly shouldnt be the problem - its only 6000 people, w/ listed boolean and alphabetizing results). thanks, ~alan

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RE: [Zope] MySQLDA / MySQLdb problems
by Eric Walstad 13 Mar '00

13 Mar '00

Hi Dave, Unfortunately, I don't have an answer yet. I am still trying to get the damn thing to work. I had ZMySQLDA working until I tried to run a query. Then I got the same error that I got when using MySQLdb. Right now I am in the process of wiping everythin out (short of Linux itself) and will try a re-install. I hate doing this because I still don't understand the source of the problem! Anyway, I'll keep you updated... Eric >Greetings, > >So What was the answer????????? >I am going to attempt an upgrade of MySQL. >Dave > > > > >

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RE: [Zope] Zope needs this (and Dynamo has it)
by Alexander Staubo 13 Mar '00

13 Mar '00

> From: 'Martijn Faassen' [mailto:faassen@vet.uu.nl] > Sent: Sunday, March 12, 2000 12:11 AM > To: Zope Mailing List (E-mail) > Subject: Re: [Zope] Zope needs this (and Dynamo has it) > > [snip] > [snip explanation why open-source like collaboration is > harder for languages] > > It's hard for language *design*, yes, but it's less hard when > you're doing > language implementation (for instance a faster one), and it's > easier still > when you're writing libraries and such. And it does happen > for language > design as well -- the Python static type design is currently > being fleshed > out (in bursts) by the types-SIG (though of course Guido does final > approval about what goes into Python proper). Indeed, but do I need to remind you that we're still at version 1.52? :-) And as for your argument that OSS boosts language implementation, true in theory, but sitting down with a compiler and changing it, or building a compiler from scratch, is a daunting and time-consuming task. I have, certainly, thought about building a native-code compiler for Python. But no time right now. Your comments are well received. I hope I can put my own comments to shame in the future by committing some of my resources to the Python effort. As for the types-SIG, I've read through Guido's latest proposal, and found it so-so; I have some comments about the syntax -- which IMHO is heading in the right direction, but I feel it's still quite unpolished, like the new "decl" keyword and the very odd, un-Pythonic "->" operator. Other than that, it looks a lot like I had in mind myself. [Re: C++ extensions with Python] > There are various tools out there for Python which do offer > this kind of > functionality, though, I think? Check at the vaults of > parnassus sometime: > http://www.vex.net/parnassus Not sure which you mean. Found this one: http://www.vex.net/parnassus/apyllo.py?i=52521115 > > Let me finish the last sentence first: I also have a > database-centric > > Zope app that causing me headache. The ZODB is *way* too immature to > > replace a database right now -- fine for the kind of stuff > that runs on > > zope.org, not for us. We're actually looking at alternative > app servers > > and solutions (such as hardwired C++ CGI code) right now. > It's a shame, > > and I'm fighting it, but we might end up with something like Dynamo. > > I'll repeat my question; why not use a relational database? Do you > need an object database? How is the ZODB too immature? Interestingly enough, I'm discussing this with Jon Udell on his Byte newsgroups (go news.cmpnet.com) I'll quote something I wrote in this discussion, slightly edited for clarity: <quote> I can't easily tell Zope that objects of type A refers to objects of type B (mutual relationships), and that objects of type B should not be deletable as long as an object of type A is referring to it (referential integrity). The only kind of relationship Zope knows about is containment, a parent-child relationship. There is simply no other way for an object to refer to another object. Consider the case of news articles. Let's say articles should be able to hold multiple sections of text, as well as images. Assuming we use Z Classes and not Products, two solutions come to mind: Either (a) let an article be a descendant of Zope's folder or object manager classes, and thus contain any such sub-data as objects -- a design which currently is the most useful, but which has its shortcomings -- or (b) let sub-data exist as objects elsewhere in the ODB, and have string attributes on the article object that refer to their names, eg. an attribute "Illustrations" of type "lines" containing image IDs such as "mayor.jpg", "airplane.jpg" etc. This is obviously ugly -- for example, these image objects could be moved or removed and the article object would never know. As for dividing article texts into multiple sections (page 1, page 2 etc., with appropriate headings), this is obviously pretty simple with scheme (a), but in the case of (b), the text could exist in one large attribute, and some sort of page tagging system might be enforced -- or we could go all the way and do XML. So far, with these solutions, we'll survive. Cracks begin to show when we start thinking about organizing authors, publications, and document flow. Zope doesn't provide a framework to solve this things. Equally worse is that the ZODB hierarchy is so easily polluted with things that don't belong there. You end up putting a lot of objects in the root folder because they're needed globally -- and anyone who has used Zope will tell you that a folder becomes unwieldy and disorganized when it grows past 20+ objects. (Case in point: Personally, several of my Zope sites have a root-level Utils folder containing oft-used External Methods, because they tend to pollute the whole namespace.) Zope needs a multiple-root, "multihomed" hierarchy. Z Classes must be able to exist anywhere, not just in the one Products hierarchy. </quote> [Re: Python syntax issues] > > I don't necessarily say they're _my_ problems, but some people think > > they are, and that counts. I don't miss "switch" myself, > although I do > > miss a kind of enumerated type. > > Like this? > > FOO, BAR, BAZ = range(3) > > [snip neat example of the use of eval() in Python] No, although that's a clever trick. Hey, do it again! :-) What you cite above may mirror the effect of an enumerated type, but it doesn't contain any meta-information about the type itself: That is, FOO, BAR, BAZ are integers. They will fit into any integer expression and can be passed to any function taking integer arguments. The function won't balk if you pass a value from another "enumeration". Another problem with the above is that there is no way to ask Python to enumerate the values or names in the sequence, because its values are part of the top-level namespace -- I don't like that kind of namespace pollution. Instead, perhaps, this: class Enum: def __init__(self, Value): self.Value = Value def __int__(self): return self.Value class DeadParrot(Enum): FOO, BAR, BAZ = range(3) def PetShop(P): if int(P) == DeadParrot.FOO: print 'It''s resting.' D = DeadParrot(DeadParrot.FOO) PetShop(D) ...But hardly elegant. > > > I don't think you'll see protected members any time soon. > > > > I think Zope's source code is one huge, glowing argument in > favour of > > having protected members. > > Why so? I myself think Zope's source is an argument for > explicit interfaces. :) The same side of two different coins, I think. :-) > > Tuples are immutable, dicts and lists are mutable. Why? > Because Guido > > says so. Jon Udell, I think it was, has argued that tuples > are currently > > a redundant element in the language. Why have two kinds of lists? It > > just confuses people. > > Well, tuples can be used as dictionary keys, lists cannot. And that makes sense to you? I don't know the historical significance of tuples in Python -- I know the mathematical meaning, but Python tuples aren't quite it -- but it smells a lot like an interface that has been fit to the size of the implementation. A lot like, coincidentally, a procrustean bed. (Coincidentally because the term has popped up a lot lately; see the Byte thread.) > > A syntax for declaring the mutability of types would be helpful in > > clearing out this mess. For example, you should be able to declare a > > dict to be immutable when passed to a certain function call -- ie., > > forcing a copy. > > Forcing a *copy*, implicitly? But Python works with reference > semantics > only? It's be nice to have a way to declare stuff immutable, I think, > but I'm not sure how often one would need to use it. There's something > to say for knowing something's a tuple, instead of having a list and > having to know whether it's immutable or not. Though perhaps that's > not a big problem in practice. I think the idea that mutability as a behaviour is distributed among primitives is, frankly, a questionable design choice. ;-) > > Python has no "out" parameter, only "in" parameters that > > are mutable depending on the type of the object passed. The > syntax I'm > > alluding to would effectively give you both "out" and "const" > > parameters. (No, it would not -- it would effectively give you both "out" and *pass-by-value* parameters.) > But that might result in a lot of incomprehensible code. I'm > not sure if > I'm in favor of having 'out' parameters anyway. The alternative is returning dictionaries or tuples, is it not? Maybe I'm not thinking in a Pythonic vein. Maybe A, B, C = GetABC() is more immediately grokkable than GetABC(A, B, C) # assuming these are "out" parameters Well. Sure it is. Damn, I think you're right. ;-) -- Alexander Staubo http://alex.mop.no/ "`Ford, you're turning into a penguin. Stop it.'" --Douglas Adams, _The Hitchhiker's Guide to the Galaxy_

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EAGAIN errors crashing ZServer Aiieeee!!!!
by Jon Prettyman 13 Mar '00

13 Mar '00

Okay, this is what I'm getting consistently when my server crashes under moderate load: ------ 2000-03-13T18:53:02 INFO(0) GUF Successful authentication for user April (http://207.241.10.50/premium/acl_users) ------ 2000-03-13T19:01:40 INFO(0) GUF Successful authentication for user thomas (http://www.nationalmortgagenews.com/premium/acl_users) ------ 2000-03-13T19:02:24 INFO(0) GUF Successful authentication for user terrydpeters (http://207.241.10.50/premium/acl_users) ------ 2000-03-13T19:03:36 ERROR(200) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Aiieee! 17065 exited with error code: 11 ------ 2000-03-13T19:03:36 INFO(0) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Houston, we have forked ------ 2000-03-13T19:03:36 INFO(0) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Hi, I just forked off a kid: 17125 ------ 2000-03-13T19:03:36 INFO(0) zdaemon zdaemon: Mon Mar 13 13:03:36 2000: Houston, we have forked ------ 2000-03-13T19:03:58 PROBLEM(100) ZServer Cannot do reverse lookup ------ 2000-03-13T19:03:58 INFO(0) ZServer Medusa (V1.13) started at Mon Mar 13 13:03:58 2000 Hostname: 207.241.10.50 Port:80 ------ 2000-03-13T19:03:58 INFO(0) ZServer FTP server started at Mon Mar 13 13:03:58 2000 Authorizer:None Hostname: magmar Port: 8021 >From the debug log: B 144485000 2000-03-13T19:03:02 GET /nmn/images/marketplacebutton.gif I 144485000 2000-03-13T19:03:02 0 A 144485000 2000-03-13T19:03:02 304 182 E 144485000 2000-03-13T19:03:02 B 144484496 2000-03-13T19:03:09 GET /id.htm I 144484496 2000-03-13T19:03:09 0 A 144484496 2000-03-13T19:03:09 200 3740 E 144484496 2000-03-13T19:03:09 B 143155832 2000-03-13T19:03:10 GET /newsubsid.gif I 143155832 2000-03-13T19:03:10 0 A 143155832 2000-03-13T19:03:10 200 45513 E 143155832 2000-03-13T19:03:10 B 145239016 2000-03-13T19:03:14 GET /nmn/images/marketplacebutton.gif I 145239016 2000-03-13T19:03:14 0 A 145239016 2000-03-13T19:03:14 304 163 E 145239016 2000-03-13T19:03:14 B 146772968 2000-03-13T19:03:32 GET /nmn/images/afstitle.gif I 146772968 2000-03-13T19:03:32 0 A 146772968 2000-03-13T19:03:32 304 182 E 146772968 2000-03-13T19:03:32 B 139605816 2000-03-13T19:03:59 GET /nmn/images/marketplacebutton.gif I 139605816 2000-03-13T19:03:59 0 A 139605816 2000-03-13T19:04:01 304 163 E 139605816 2000-03-13T19:04:01 B 139494360 2000-03-13T19:04:07 POST /premium/acl_users/register I 139494360 2000-03-13T19:04:07 518 A 139494360 2000-03-13T19:04:10 200 8704 E 139494360 2000-03-13T19:04:10 B 139787784 2000-03-13T19:04:28 GET /nmn/images/marketplacebutton.gif I 139787784 2000-03-13T19:04:28 0 A 139787784 2000-03-13T19:04:28 304 182 E 139787784 2000-03-13T19:04:28 I'm running Linux 2.2.12-20, Zope 2.1.4, currently with only ZServer (and FTP server.) Things get even flakier when I am running with PCGI. -Jon

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