April 2000 - Zope-Dev

ZClass arguments dilemma
by Kevin Howe 29 Apr '00

29 Apr '00

Hi All, I have a ZClass and would like to add a method to it which would allow overriding arguments to be passed to it via dtml: Example: <dtml-with myZClassInstance> <dtml-var "myMethod( link='http://domain' )"> </dtml-with> The values for the given variables (link) would be used instead of the object's Property values. The problem I have run into is that when an object method is called via DTML as above, the entire REQUEST of the object is replaced, denying accessing to the object's Property values and Methods. Example: myMethod() would no longer have access to <dtml-var id> because "id" wasn't supplied in the DTML call. All ZClass Methods or Properties are no longer available. In a Python Product you can still access the values because "self" is passed: Example: def myMethod (self, title): # use "command line" argument if given if title: pass # otherwise use the Property value else: title = self.title But with the ZClass, I can find no clear way to pass the self values for that object. Example: <dtml-with myZClassInstance> <dtml-var "myMethod( self, link='http://domain' )"> </dtml-with> What is the correct way to go about this? Thanks :) kh

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Data.fs corruption when creating lots of objects.
by R. David Murray 28 Apr '00

28 Apr '00

More info on the database corruption. I took out my reindex_object call (to reduce the ZCatalog activity), and did a get_transaction().commit() after every object addition. The load failed when it filled the disk at 6GB of data. So I went back and started loading it in 2500 record chunks and packing after each one. The first chunk resulted in a 177 MB Data.fs file. A pack on this took it down to 8MB. Loading the second chunk ballooned it to 295MB. Packing that resulted in the error I saw before when doing the load by sections: Error Type: CorruptedTransactionError Error Value: /usr/local/zope/directory/var/Data.fs data record exceeds transaction record at 185738594 Tranalyzer says: Traceback (innermost last): File "tranalyzer.py", line 333, in ? main(sys.argv) File "tranalyzer.py", line 325, in main t = Transaction(f, off, refs) File "tranalyzer.py", line 170, in __init__ self.obs.append(Record(f, refs)) File "tranalyzer.py", line 211, in __init__ self.vstring = f.c(vl - 16) File "tranalyzer.py", line 105, in c self.checkleft(n) File "tranalyzer.py", line 87, in checkleft raise 'Not enough data left, %d < %d' % (self.left, n) Not enough data left, 6816 < 23567 so it finds the same problem. Looking at the Tranalyzer output, it looks like I have three objects per record added after a pack, but about 52 objects in each transaction before packing. As the load progresses, some of these objects get rather large (>16K). What's going on here? The amount of data and objects being thrown around here seems *totally* crazy. I'm especially puzzled by those larger and larger object sizes during a load, given that the size of the input records is consistent. The objects that remain after packing are of a very reasonable size (around 350-400 bytes each). And why does the addition of a single new ZClass instance result in *52* objects in the transaction, when I would assume that only the Catalog and the containing folder are getting modified in the transaction? (For review, I'm adding a simple catalog aware ZClass object that has about a dozen properties, but I'm trying to add a little less than 60,000 of them). Can anyone with some knowledge of how the ZODB in general and FileStorage in particular works give me a clue what is going on here? Is this really normal behavior, to need this huge amount of disk space to handle what seem to be simple updates? I'm trying to narrow down the corruption to a quickly repeatable operation so I can start to insturment what's going on, but I'm really puzzled by what the Zope transaction/object machinery is doing here. --RDM

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RE: [Zope-dev] Problem with reading zope objects from external me thod.
by Chris McDonough 28 Apr '00

28 Apr '00

The Image object's data attribute is what you want. AFAIK, you need to use consruct a StringIO object with the data in from the data attribute (it makes a chunk of data look like a file object). PIL doesnt seem to support any other method of reading a chunk of data but from an object that looks like a file. > -----Original Message----- > From: Anders Lide'n [mailto:al@netg.se] > Sent: Friday, April 28, 2000 2:54 AM > To: zope-dev(a)zope.org > Subject: [Zope-dev] Problem with reading zope objects from external > method. > > > > I want to draw a circle on a picture that I have stored > inside zope. Since > the image manipulation module (PIL) is a module not usable from inside > zope I have to use an external method. > > The external method now needs to read in the file (the > picture) and this > file is located inside zope as a zope object (image file). > Hence : I need > to get the external method to read a zope object. But I > continually fail > to read the zope object, how do I do? > > Anders Lidén NetGuide / TerraTel AB > al(a)netg.se Tankegången 4 > Url:http://www.netg.se/ 417 56 GÖTEBORG > Mobile : 0736 - 73 55 32 +46 - (0)31 - 50 79 69 > > > _______________________________________________ > Zope-Dev maillist - Zope-Dev(a)zope.org > http://lists.zope.org/mailman/listinfo/zope-dev > ** No cross posts or HTML encoding! ** > (Related lists - > http://lists.zope.org/mailman/listinfo/zope-announce > http://lists.zope.org/mailman/listinfo/zope ) >

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Transparent folders?
by Martijn Faassen 28 Apr '00

28 Apr '00

Hi there, Recently I've had an idea. Problem description: I'm sure lots of people will recognize this. The root folder fills up with lots and lots and lots of methods; both factored HTML layout components and methods that should apply to all subfolders. Ideally you'd want to put this stuff in subfolders. But you run into the following problem: acquisition works no more. That is, acquisition works, but to override any specific layout component that's in a subfolder, you need to override the entire subfolder and copy over *all* layout elements. That's not what we want. I haven't seen an easy solution to this problem yet, unless I'm missing something. Analysis: So, why do you want to use folders at all? To compartementalize the system so we can easily find stuff. To avoid long lists of methods in the root folder. But proper folders hurt acquisition, so.. Solution: We need a new type of folder, the 'transparent' or 'virtual' folder. If we have a folder 'folder', and a subfolder 'sub', and sub is a transparent folder, anything we place in 'sub' is actually in 'folder' as well. It'll be acquired. It can be overridden (either in a subfolder of the same name, or in the folder that's doing that acquiring directly). This way, we get to compartementalize things while keeping the benefits of acquisition. Actually, this idea could have deep consequences, as it's getting very close to (multiple) inheritance. That is, if you put a transparent folder in your folder, it's like saying the current folder inherits from that transparent folder. Perhaps transparent folders could then also be generalized for a new type of ZClass inheritance that may or may not be easier to manage than the current system. Imagine being able to drop a transparent folder in your ZClass to make it inherit the methods in that transparent folder. ZClass inheritance needs an extra bit, though; the ability to make a 'reference' transparent folder that does not have actual methods inside itself, but just refers to some other ZClass (or Python base class, or whatever). Let's just stick to my original transparent folder idea for now, keeping all this inheritance zen in mind for later. My questions are: * is this a good idea at all? Any disastrous complications or consequences? * is this technically feasible? Regards, Martijn

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Confera Topic
by Chimezie Thomas-Ogbuji 28 Apr '00

28 Apr '00

Any one run into a regexpr bug/error when using Confera Topic to post a message that has a CR in it? It pukes when I enter a message with a CR anywhere, which really makes it difficult to quote messages when responding to them chime

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LocalFS Object
by Chimezie Thomas-Ogbuji 28 Apr '00

28 Apr '00

I'm having a problem instanciating a LocalFS Object. I created an object that pointed to /usr/bin called it binaries and tried to access it via management interface or via url and get an error. I've attached two html files: manage_error.html and web_error.html with error messages for the corresponding access methods. any suggestions? chime

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ZCatalog space consumption question
by Kevin Dangoor 28 Apr '00

28 Apr '00

If I have a ZCatalog with a whole bunch of indexes and metadata fields that tracking many different types of objects, will there be space wasted for the fields that *don't* appear in a given object? For example, if "foo" is in the metadata table, but my "Bar" ZClass doesn't have a "foo" property, will some amount of space be wasted in the catalog for "foo" or will "foo" just be ignored? Kevin http://www.byproducts.com - Humor and Novelties

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Re: [Zope] Permissions for properties - argh
by Lalo Martins 28 Apr '00

28 Apr '00

On Fri, Apr 21, 2000 at 10:08:12PM -0300, Lalo Martins wrote: > Can't I keep users from _reading_ properties in a ZClass? I > already mapped "Access content information" to a permission > only Manager has... but then I create a DTML Method (no proxy > roles) with <dtml-var "object.subobject.property"> and it > renders, even for Anonymous... what gives? Ok, no sollutions... I tried to look for this in the sources but no success either... what pieces of code are involved in reading a property of a ZClass-based object? There are too many classes in ZClass/*.py, I didn't exactly understand what each of them is for. We badly need at least some UML :-( []s, |alo +---- -- Hack and Roll ( http://www.hackandroll.org ) News for, uh, whatever it is that we are. http://www.webcom.com/lalo mailto:lalo@hackandroll.org pgp key in the personal page Brazil of Darkness (RPG) --- http://zope.gf.com.br/BroDar

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NT Event Log
by Toby Dickenson 28 Apr '00

28 Apr '00

Is anyone looking at getting Zope log events into an NT event log? Would anyone be interested in testing such a logger? Toby Dickenson tdickenson(a)geminidataloggers.com

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Zope Presentation
by Thomas Weholt 28 Apr '00

28 Apr '00

Hi, I`m thinking about doing a presentation of Zope to the rest of my company. At this point the company is based entirerly on Microsoft software and has great knowledge of ActiveX and COM-objects, MS SQL Server 7 etc. How could I best present Zope in light of what employees at my company allready know? It`s important that we can use most of our products and technology from inside Zope. In addition to this, I`d like to know what the best arguments for using Zope ( like open-source, free, extendable etc. ). Thanks!! Thomas

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