May 2001 - Zope-Dev - Zope lists

OR mapping proposal
by Shane Hathaway 16 May '01

16 May '01

http://dev.zope.org/Wikis/DevSite/Proposals/ORMappingDB Comments encouraged! Shane

3 3

Re: [Zope-dev] OR mapping proposal
by Shane Hathaway 15 May '01

15 May '01

On Tue, 15 May 2001, Phillip J. Eby wrote: > If we had a standardized manipulation API or idioms (like JavaBeans) for > application objects, then having lots of ways to *implement* storage would > be a good thing. Different products and offerings could co-exist and > compete in the storage implementation space, and users would have the > benefits of being able to choose their back-ends and app frameworks without > being locked into one framework's API. That sounds useful, though I've been hinting at a more gradual approach. For example, I might define an OR mapping like this early on (roughly): class UserMapping (ObjectMappingScheme): def loadState(self, object, key, store, cursor): records = cursor.execute('select login, password from users' ' where uid=%(key)s', {'key': key}) d = object.__dict__ r = records[0] d['id'] = key d['login'] = r['login'] d['__'] = r['password'] def storeState(self, object, key, store, cursor, transaction): d = object.__dict__ cursor.execute('update users set login=%(id)s password=' '%(__)s where uid=%(id)s', d) Then I might see that many tables conform to a pattern and I would convert it to this: UserMapping = SimpleAttributeMapping(table='users', {'id':'uid', 'login':'login', '__':'password'}) Then I could make a web interface for creating SimpleAttributeMapping objects. Of course this is just the simplest case and things get more interesting when you have hierarchies of objects or complex queries. > Perhaps I should offer up a counter-proposal, focused on establishing a > common API and proposing some of the requirements for same? Presumably we > are all agreed that it should be as Pythonic as possible, but no more so. > :) Also, API is perhaps not the right word, it is more about access and > manipulation idioms. It needs to deal explicitly with the notion of > relationships as well as "attributes" in the sense of data fields. And it > needs to deal with the notion of how you determine what classes should be > used for what things and how to get at those classes (since they may need > to be backend-specific). You mean a "complementary" proposal, don't you? > These are issues, by the way, which the current ZODB API dodges, and that > is why I've been saying that doing O-R mapping in ZODB doesn't help the key > issues of database independence. You *still* have to code to a style that > is compatible with changing back-ends. I think it might be helpful if we > all got on the same page about what that style should be, and then all > these efforts could go forward knowing that in the Zope application space, > users will only need to learn one such style at the Python level, and any > education efforts about that style can be leveraged across many possible > implementation approaches. Sounds great! Shane

1 0

Filling Selection Field in Input Form
by florian_reiser＠gmx.de 15 May '01

15 May '01

Hi folks, i program an pivot table as an product. At the initialisation of the instance the user sets what SQL method he wants to use. Do you have me a tip how I can get the field names in my form, so the user can select which he wants to see? The SQL methods name is stored in a variable called _query inside the instance. How can I get the SQL method stored inside _query to execute and return its result? thanks in advance florian -- ----------------------------------------------------------------------- | Florian Reiser PGP-Key:0x5368CF3F | | PGP-Fingerprint: 84C7 24BC F3A4 487F CBC7 692C 05DB 6E11 5368 CF3F | -----------------------------------------------------------------------

1 0

[Zope-dev]: zshell
by Homan Els 15 May '01

15 May '01

Hi, Does any one has an example how to use the zshell ? I would like to use it. But, I cannot find many documentation on it. Thanks, Els

2 1

Re: [Zope-dev] Experiments with ORMapping
by Shane Hathaway 15 May '01

15 May '01

"Phillip J. Eby" wrote: > > At 05:42 PM 5/11/01 -0400, Shane Hathaway wrote: > >"Phillip J. Eby" wrote: > >> I'm not quite clear on how exactly you suggest mapping from RDMBS -> > >> ZODB. There's a *significant* (IMHO) impedance mismatch between ZODB's > >> arbitrarily identified variably structured single records and SQL's > >> content-identified fixed-structure record sets. This is what application > >> frameworks/toolkits (such as your own DBAPI product) are needed for. > > > >If you implement this at the Storage level, yes, there is a major > >mismatch. But at the Connection level it makes a lot of sense. > >Connection basically exposes a pile of pickles as objects; an OR mapping > >exposes a complex schema as objects. > > > >I think that understanding will change the rest of your response. :-) > > > > Nope. As far as I can see, all that does is leverage ZODB Connections as a > crude sort of Rack that only provides a mapping-like interface for > retrieving objects, without helping any of the higher-order needs of an > application. I guess if you define O-R mapping as "can you store and > retrieve an object's properties from a database", then I guess you've > succeeded at that point. But if that was all my O-R apps needed, there > would've been no reason to use the RDBMS; I could've just used ZODB and a > BTree with less bother. I'm telling you there's a lot more you can do with the code that makes up ZODB. The mapping interface is not the key to the way Connection does its work. OIDs don't have to be strings. If we just use cPersistent, cPickleCache (which is misnamed), and Transaction to implement an OR mapping, here's what we get for free: - A transparent, transactional database. - Potential interoperability with everything written for ZODB. - Robust, tested code. - Optimizations in C. Since you challenged me :-) I decided to put together a prototype. What I came up with was a database connection that sets a different _p_jar for each persistent object. The _p_jar is an object that manages the storage for only one persistent object, making it possible to customize the storage. There was only one hurdle in this approach but I hacked around it: the tpc_* messages get sent to each _p_jar. Then I wrote a very minimal test that doesn't connect to an RDBMS but stores and retrieves simple objects in a dictionary. OIDs are still necessary to support multithreaded invalidation messages. But the OIDs in the prototype are a tuple consisting of a schema ID and a record ID. That way the record IDs only need to be unique within an RDBMS table (or combination of tables.) I didn't think anything like this was possible before I got to know Jim. I still didn't understand when he presented the idea months ago. But now I see the idea really is workable. The advantage is that it lets us completely isolate RDBMS storage details from the application. The next thing to do is to write a fishbowl proposal. Shane

6 17

xmlrpc: Syntax error at line 34: illegal character in content --> Look at what I found out
by Ulrich Eck 15 May '01

15 May '01

Hi chris, hi dieter, I also have this problem with using xmlrpc from a python client with zope. > > RuntimeError: Syntax error at line 34: illegal character in content > > This was the bane of one of our projects to the point where Andy re-wrote > ZMailIn to no-longer use XML-RPC. > > It's to do with stuff-which-should-probably-be-entities but we never tracked > down what wasn't encoding something when it should have done. > I'd blame the marshalling code in xmlrpclib.py myself. > > If you ever fix this, do let us know :-) > I have a Zope 2.3.1 server running as well as a Zope 2.3.2. I developed an Service-Framework on the first and then tried to install it on the 2.3.2 .. it failed I printed out the raw data of the transmission and they differ: When I call the function on Zope-2.3.1 i get this response: --------------------------------------------------------- <?xml version='1.0'?> <methodResponse> <params> <param> <value><string>OK</string></value> </param> </params> </methodResponse> --------------------------------------------------------- when I call the same function on the same backend on Zope-2.3.2 I get the following: --------------------------------------------------------- X-Powered-By: Zope (www.zope.org) Python (www.python.org) Content-Length: 128 Connection: close Content-Type: text/xml <?xml version='1.0'?> <methodResponse> <params> <param> <value><string>OK</string></value> </param> </params> </methodResponse> --------------------------------------------------------- There is some header-information in the body (that perhaps shoudn't be there) Where there any changes in Zope 2.3.1 -> 2.3.2 in the Publishing part ?? With the second response the xmllib-parser won't work as we see. any suggestions to that ?? did you guy's updated to Zope-2.3.2 recently ?? thanks for any response and hope this helps a bit .. Ulrich Eck net-labs

1 0

zope early win32 binaries
by Sin Hang Kin 15 May '01

15 May '01

Plesase consider release the binaries for python2(.1) for win32 asap. As my understanding, the current c extensions were pretty stable for zope. what have been under major re-construction is purely in python. Would DC care to release an PYD (DLL) only sub-package for win32 users to test the up-comming zope? I hope all would be pleased. Rgs, Kent Sin --------------------------------- kentsin.weblogs.com kentsin.imeme.net

1 0

Proposal: AuthenticatedRole
by Chris McDonough 14 May '01

14 May '01

Hi all, If you're concerned or curious, please review this proposal on the fishbowl regarding adding a default role to Zope named 'Authenticated': http://dev.zope.org/Wikis/DevSite/Proposals/AuthenticatedRole

1 0

Re: oodb philosophics ;) was: Re: [Zope-dev] Experiments withORMapping
by Karl Anderson 14 May '01

14 May '01

Casey Duncan <cduncan(a)kaivo.com> writes: > I am not arguing necessarily for SQL as a query language for the ZODB. > Although it is an accepted standard, but not a perfect one by any means > especially for OODBs. Its appeal lies mainly in the high level of > community familiarity and the plethora of SQL software to borrow from. Does anyone have an opinion on the possible usefulness of XPath, XQuery, and other XML standards for this? Someone suggested (on the zope-xml wiki) that it would be nice to be able to drop in a cataloger that supported a presumably standard and presumably well-known XML query syntax, and which would work throughout the database because Zope objects would support DOM. This is all speculation, and I personally don't know much right now about XML database interfaces and how finished or well-regarded they are. -- Karl Anderson karl(a)digicool.com

2 1

Disabling anonymous webdav access
by Ivo van der Wijk 14 May '01

14 May '01

Hi All, As someone pointed out on #zope, it is possible to view folder contents using a webdav client as an anonymous user. I.e. download cadaver (http://www.webdav.org/cadaver/) open yourzopeserver:8080 and do ls. Then decide if you want anyone to be able to access this. Eventhough hiding this information may be security by obscurity, there are some things you just don't want everyone to see. This allows you to see, for example, the installed products on the server. A hacker might use this knowledge to exploit some known bug in a zope product if one exists. Most people (like me) probably think it's harmless to let old objects, documents etc linger around as you can't view them in listings through ftp or http. They don't realize webdav is running by default. Actually, it can't even be disabled! (z2.py -X -w80 won't do the trick!) Personally I'd rather see this secured. It's not possible to disable 'view contents information' for anonymous users in zope, as this will ruin your entire site (all anonymous access will then be disabled), so the solution would be to create a new permission for access contents through webdav. And that's what the following (trivial) patch does. After applying you'll get a new permission in your security tab, which is set to manager by default. To get the old behaviour back, just set the permission back to anonymous. Apply it using patch -p1 ../webdav.patch in your SOFTWARE_HOME (i.e. the Zope-2.3.2-src dir). Or just edit lib/python/webdav/Resource.py by hand :) I've tested it with Zope 2.3.2, I can't guarantee it will work with other versions (use at your own risk anyway). -- cut here -- *** Zope-2.3.2-orig/lib/python/webdav/Resource.py Tue Mar 27 21:50:37 2001 --- Zope-2.3.2-src/lib/python/webdav/Resource.py Mon May 14 19:16:46 2001 *************** *** 109,115 **** __ac_permissions__=( ('View', ('HEAD',)), ! ('Access contents information', ('PROPFIND',)), ('Manage properties', ('PROPPATCH',)), ('Delete objects', ('DELETE',)), ) --- 109,115 ---- __ac_permissions__=( ('View', ('HEAD',)), ! ('Access contents information through WebDav', ('PROPFIND',)), ('Manage properties', ('PROPPATCH',)), ('Delete objects', ('DELETE',)), ) -- cut here -- Cheers, Ivo -- Drs. I.R. van der Wijk -=- Brouwersgracht 132 Amaze Internet Services V.O.F. 1013 HA Amsterdam -=- Tel: +31-20-4688336 Linux/Web/Zope/SQL Fax: +31-20-4688337 Network Solutions Web: http://www.amaze.nl/ Consultancy Email: ivo(a)amaze.nl -=-

1 0