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Changing a Z object's __class__ dynamically
by Hung Jung Lu 20 Aug '00

20 Aug '00

Hi, One powerful feature of Python is the ease of reloading modules. This makes debugging extremely nice, since you can modify the code, reload the module, and all this while the main program is still running. Moreover, if a particular instance object has been created, you can actually edit the object's class code, reload the module, and change the class of the object to the modified class. Something like: my_module = sys.modules['module_name'] reload(my_module) my_new_class = my_module.my_class my_instance.__class__ = my_new_class This works all very nicely in pure Python. But not in Zope. When the object is a Zope object, somehow the last statement does not seem to do anything. That is, the object's class is not updated. I don't know what exactly is going on. My conjectures are: (1) Digicool people have re-written Python's system function setattr(), so that when it is an Z Object, the __class__ cannot be changed. (2) Caching: when I change the class of a Z Object, somehow it does not reflected in the Z Object's memory-cached version. At any rate, this is really surprising. Since usually when you do: x = 3 print x you would expect the result to be 3. But with a Z object's __class__, you can assign it to something, and then nothing happens. That is: x.__class__ = new_class print x.__class__ and it will print the old class, not the new class. Does anyone know what I can do to change the class of a Z object dynamically? This will make the development of Zope products a lot easier. (Of course, all these reloading features are extremely dangerous, so it's best to use them only for development and strip them from the code at the end.) regards, Hung Jung ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com

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Zope on AlphaStationNT...
by Jim Hoepner 20 Aug '00

20 Aug '00

I am a total Zope newbie. I am trying to run Zope on a AlphaStation running NT. I get a "service specific error 1" when I try to start Zope. I am using a utility called FX!32 which lets me run Win32 programs on my Alpha. "Compaq FX!32 (TM) lets you install and run 32 bit, x86 programs on your Windows NT Alpha system." Does anyone have any info that might help? Please reply to jrhoepn(a)tvsw.org as I am not subscribed to the list yet. Thanks! jrh

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Yihaw "Properties" creates error
by Sean Kelley 19 Aug '00

19 Aug '00

When I click "Properties" on a new Yihaw folder, I get the following Zope error. What does it mean? Error Type: NameError Error Value: Catalog Troubleshooting Suggestions This resource may be trying to reference a nonexistent object or variable Catalog. The URL may be incorrect. The parameters passed to this resource may be incorrect. A resource that this resource relies on may be encountering an error. For more detailed information about the error, please refer to the HTML source for this page. If the error persists please contact the site maintainer. Thank you for your patience. © Copyright 1995-2000 ALL RIGHTS RESERVED Traceback (innermost last): File /home/kelley/Zope-2.1.6-src/lib/python/ZPublisher/Publish.py, line 214, in publish_module File /home/kelley/Zope-2.1.6-src/lib/python/ZPublisher/Publish.py, line 179, in publish File /home/kelley/Zope-2.1.6-src/lib/python/Zope/__init__.py, line 202, in zpublisher_exception_hook (Object: CatalogAware) File /home/kelley/Zope-2.1.6-src/lib/python/ZPublisher/Publish.py, line 165, in publish File /home/kelley/Zope-2.1.6-src/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: manage_folderproperties) File /home/kelley/Zope-2.1.6-src/lib/python/ZPublisher/Publish.py, line 102, in call_object (Object: manage_folderproperties) File /home/kelley/Zope-2.1.6-src/lib/python/OFS/DTMLMethod.py, line 150, in __call__ (Object: manage_folderproperties) File /home/kelley/Zope-2.1.6-src/lib/python/DocumentTemplate/DT_String.py, line 502, in __call__ (Object: manage_folderproperties) File /home/kelley/Zope-2.1.6-src/lib/python/DocumentTemplate/DT_In.py, line 633, in renderwob (Object: Catalog(meta_type='Yihaw Pointer')) File /home/kelley/Zope-2.1.6-src/lib/python/DocumentTemplate/DT_Util.py, line 335, in eval (Object: Catalog(meta_type='Yihaw Pointer')) (Info: Catalog) File <string>, line 0, in ? NameError: (see above)

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Re: [Zope] tree tag woes continue :S
by Dieter Maurer 19 Aug '00

19 Aug '00

Chris Withers writes: > ... > My idea, as you may have seen from recent posts, was to do a dtml-in > over the first set of children so I could do the batching there, and > then do a dtml-tree for each one of them to get the tree as before. > > Is this a good or a bad idea? > Is having lots of dtml-tree's on the same page acceptable or not? I think, it is acceptable from a user point of view. I am not sure, whether they behave well, because all trees share a single cookie value, tree-s, to maintain there state. At least some operations on one treem, e.g. "collapse_all", may have adverse effects on the state of other trees. However, maybe, you are lucky. Up to now, I did not yet see problems with several trees in several pages which should be the same problem. > I'm currently trying: > > <dtml-in postingValues> > <dtml-with "_.getitem('sequence-item',0)"> > <dtml-tree branches="postingValues"> I would expect: <dtml-tree sequence-item branches=postingValues> Dieter

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Re: [Zope] Newbie Question (Content Manager Tutorial)
by Dieter Maurer 19 Aug '00

19 Aug '00

Hi Mark, Mark A. Pappas writes: > I installed Zope 2.2.0 .... > I dloaded the Content Manager Guide .... > ... > Zope Error > Zope has encountered an error while publishing this resource. > > Error Type: SuperCannotOwn > Error Value: Objects cannot be owned by the superuser The Content Manager Guide still describes the world before Zope 2.2. For some reason (that I do not understand), DC descided that, starting with Zope 2.2.0, the SuperUser is no longer Super but instead rather limited. He cannot own objects and therefore, he cannot create objects. What you need to do: As SuperUser go to "acl_users". Create a new user with a role of "Manager". Close your browser (all windows!). Recontact Zope (in a fresh browser!) as your newly created Manager. Use this manager, whenever your guide speaks of "SuperUser". Dieter

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Re: [Zope] Pages Half Rendering :(
by Dieter Maurer 19 Aug '00

19 Aug '00

Chris McDonough writes: > I've seen this in Netscape only, mostly while using the management > interface. I haven't been able to track it down. I wonder if it has > something to do with the bug in OFS.Image.index_html that Dieter Maurer > reported a few messages back. I've also had a problem where mgmt > interface icons don't get loaded properly, and show up broken, but on a > page reload, they get loaded properly. I doubt that the OFS.Image.index_html bug has something to do with that: Only images and files are affected. And ZPublisher seems to magically handle the "RESPONSE" return without problem. The problem only occured, because I used: <dtml-var "image.index_html(REQUEST,RESPONSE)"> The <dtml-var> probably turned the RESPONSE object it got as return value into a string and this string seriously confused the browser (as one can understand). Dieter

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tree tag woes continue :S
by Chris Withers 19 Aug '00

19 Aug '00

Okay, my aim here is to effectively have batching with trees. Why? well because a tree with over a thousand items at the root is pretty hefty to download to a browser, not to mentioned pretty antisocial to navigate and use. My idea, as you may have seen from recent posts, was to do a dtml-in over the first set of children so I could do the batching there, and then do a dtml-tree for each one of them to get the tree as before. Is this a good or a bad idea? Is having lots of dtml-tree's on the same page acceptable or not? okay, assuming it it a good idea, the tree to be replaced is: <dtml-tree branches="postingValues"> ...show stuff here... </dtml-tree> I'm currently trying: <dtml-in postingValues> <dtml-with "_.getitem('sequence-item',0)"> <dtml-tree branches="postingValues"> ...do stuff here... </dtml-tree> </dtml-with> </dtml-in> but this appears to just render the original tree once for each child. Any ideas how I should be doing this? cheers, Chris

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Nasty logging bug: product import problems
by Dieter Maurer 19 Aug '00

19 Aug '00

Have you ever had problems with the import of products? Did they simply not show up in ControlPanel.Products (or with an out of date traceback)? Did you not get any hint to the problem cause? I now can tell you why: The Zope logging system is a bit complex and weird: * While Zope is being imported, logging is done by "zLog.stupid_log_write". This nice function does not log at all unless "STUPID_LOG_FILE" is defined. Thus, first rule: *DEFINE* "STUPID_LOG_FILE", otherwise, many problems during product import happen without any glue to the problem cause. When you defined "STUPID_LOG_FILE", you will see a log entry for the problematic product: Zope Couldn't import <product>. Unfortunately, you will not get more information. This information is there, though, but it sits in the unflushed buffer of your log file. * After Zope has been imported, logging is switched to "ZLogger.stupidFileLogger.stupid_log_write". This function reopens your log file and forgets about the old opened file in "zLog._stupid_dest" and its unflushed buffer. The valuable information about the problem cause is lost. What can you do? Add at the end of "zLog.stupid_log_write" (near line 274): _stupid_dest.flush() For DC: I suggest, that "zLog" uses "ZLogger.stupidFileLogger" rather than have the code for "stupid_log_write" duplicated. Dieter

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Odd problems with SiteAccess?
by Christopher Heschong 19 Aug '00

19 Aug '00

I have a directory with a SiteAccess rule in it. Under that directory, versions and Zcatalogs no longer seem to work. This is with (SiteAccess-2-0-0b3)) and Zope 2.2.0 and 2.2.1b1 When I add a version, I can't start working in it. Clicking on the button doesn't seem to do anything. When I add a Zcatalog and try to find items to it, I get the following error: Zope has encountered an error while publishing this resource. Error Type: IndexError Error Value: list index out of range Traceback (innermost last): File /usr/local/Zope-2.2.1b1-src/lib/python/ZPublisher/Publish.py, line 222, in publish_module File /usr/local/Zope-2.2.1b1-src/lib/python/ZPublisher/Publish.py, line 187, in publish File /usr/local/Zope-2.2.1b1-src/lib/python/Zope/__init__.py, line 221, in zpublisher_exception_hook (Object: Traversable) File /usr/local/Zope-2.2.1b1-src/lib/python/ZPublisher/Publish.py, line 171, in publish File /usr/local/Zope-2.2.1b1-src/lib/python/ZPublisher/mapply.py, line 160, in mapply (Object: manage_catalogFoundItems) File /usr/local/Zope-2.2.1b1-src/lib/python/ZPublisher/Publish.py, line 112, in call_object (Object: manage_catalogFoundItems) File /usr/local/Zope-2.2.1b1-src/lib/python/Products/ZCatalog/ZCatalog.py, line 321, in manage_catalogFoundItems (Object: Traversable) IndexError: (see above) Can anyone help or suggest a way around this? I'm assuming it's a problem with SiteAccess and interaction with Zope 2.2x? -- /chris/

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How To Shoot Yourself In The Foot With Zope
by Jean Jordaan 19 Aug '00

19 Aug '00

OK, OK, there are *many* ways of shooting yourself in the foot with Zope, but I want to enter this as one of the most concise ways. Elaboration welcome. In order to get more debugging info about the environment I'm working in, I included '<dtml-var REQUEST>' in my 'standard_html_footer'. This worked so nicely, I added '<dtml-var RESPONSE>' too, arguing that the REQUEST is probably only half the story. However, adding '<dtml-var RESPONSE>' turned out to be pretty stupid, since it caused some kind of recursion (the response contains the response?) which had Zope taking up 99% of CPU and rendering *nothing*. At least, I *think* this is what happened. Enlightenment even more welcome. -- Jean Jordaan -- technical writer -- Mosaic Sofware -- Zope 2.1.6 on WinNT and W2K

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