January 2001 - Zope-Dev

MS-SQL Server Connector
by Adrian Hungate 20 Jan '01

20 Jan '01

Is there a database connector or similar for MS-SQL Server that might run on non-windows Zopes? Adrian...

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Better test case for Bug 1783: Persistent __call_method__() interferes with __getstate__
by John D. Heintz 20 Jan '01

20 Jan '01

Hello all, The following is the best test case I have so far for bug 1783. The behavior of the bug is that no CMethods from Persistent can be called indirectly when the __call_method__ hook is present. This means that I can't override any of __getstate__, __setstate__, _p_deactivate. #!/usr/bin/python import ZODB from Persistence import Persistent class P(Persistent): def __call_method__(self, meth, methArgs, methKW={}): return apply(meth, methArgs, methKW) p = P() p.__getstate__() #This throws exception! Persistent.__getstate__(p) TypeError: function requires exactly 0 arguments; 1 given -- . . . . . . . . . . . . . . . . . . . . . . . . John D. Heintz | Senior Engineer 1016 La Posada Dr. | Suite 240 | Austin TX 78752 T 512.633.1198 | jheintz(a)isogen.com w w w . d a t a c h a n n e l . c o m

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Import/Export in 2.3beta2
by Andy McKay 20 Jan '01

20 Jan '01

Is this a stupid question, or why cant i Import/Export into a folder in 2.3 b2 (Windows), there seems to be no tab... -- Andy McKay.

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ZPatterns patches
by Steve Alexander 20 Jan '01

20 Jan '01

I've put an extensive patch to ZPatterns 0-4-3b2 here: http://www.cat-box.net/steve/ZPatterns.patch The patch includes the following: * Fix to _memento class so it works with Zope 2.3 * Alteration to GAPMixin so the the attributes it says it provides come from the union of the assignments and the defaults. * Add style="width: 100%;" to SkinScript edit textarea, in line with other zope textareas. * Add syntax to SkinScript "INVALIDATE FOR". You can put an optional invalidate-for clause at the end of a compute statement. This causes the attributes provided by the statement to be invalidated from the dataskin's attribute cache when any of the attributes named after INVALIDATE FOR change. It is easier to demonstrate than to explain :-) There's also an updated PlugIns/www/main.dtml file at: http://www.cat-box.net/steve/main.dtml An example of the new SkinScript syntax: WITH SELF COMPUTE name='%s %s' % (forename, surname) INVALIDATE FOR forename, surname This is useful if you're providing attributes from another DataSkin. Here's an example from some school management software. This is an attribute provider for Pupils. A Pupil may have an Instructor. This is implemented by the attribute instructor_id of Pupil. # the instructor is only valid if the pupil is current WITH SELF COMPUTE has_instructor=instructor_id or 0 and current and 1 # don't use has_instructor below, or the instructor details for # cataloging won't get updated when the assigned instructor changes # from no instructor to having an instructor. WITH self.instructor_id and self.current and Instructors.getItem(self.instructor_id) or NOT_FOUND COMPUTE instructor_name=name, instructor_name_link='<a href="%s">%s</a>' % (absolute_url(), html_quote(name)), instructor_sort_key=sort_key, instructor=RESULT OTHERWISE LET instructor_name='no instructor', instructor_name_link='no instructor', instructor_sort_key='----', instructor=_.None The problem here is that I can't use has_instructor in the WITH clause, if I'm also using has_instructor in the same transaction as I'm updating instructor_id. I have to use "self.instructor_id and self.current" instead, as above. However, with the new syntax, I don't have to worry about that: # the instructor is only valid if the pupil is current WITH SELF COMPUTE has_instructor=instructor_id or 0 and current and 1 INVALIDATE FOR current, instructor_id WITH has_instructor and Instructors.getItem(self.instructor_id) or NOT_FOUND COMPUTE instructor_name=name, instructor_name_link='<a href="%s">%s</a>' % (absolute_url(), html_quote(name)), instructor_sort_key=sort_key, instructor=RESULT OTHERWISE LET instructor_name='no instructor', instructor_name_link='no instructor', instructor_sort_key='----', instructor=_.None Thanks to PJE for pointing me in the right direction on how to implement this. -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net

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ZPatterns: SkinScript semantics
by Steve Alexander 20 Jan '01

20 Jan '01

In a SkinScript COMPUTE statement, should I be allowed to supply different names in the OTHERWISE LET section as in the attributes section? For example: WITH some_query() COMPUTE foo,bar,baz OTHERWISE LET foo='There is no foo', spoon='There is no spoon' Looking at the ZPatterns code, I don't think this attribute provider will get registered for providing "spoon", although "spoon" will get calculated if foo, bar or baz is requested. On the other hand, you could consider the above as a shorthand for: WITH some_query() COMPUTE foo,bar,baz, spoon=NOT_FOUND OTHERWISE LET foo='There is no foo', spoon='There is no spoon' In which case, it works entirely as expected. -- Steve Alexander Software Engineer Cat-Box limited http://www.cat-box.net

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RE: [Zope] Re: Workflow and document management system in Zope
by Josh Zeidner 20 Jan '01

20 Jan '01

hey Albert, In my opinion getting something like this together can not be done in less than 1 year. I'm familiar with workflow systems and very familiar with Zope. The projects you mentioned at the end of your letter are hardly of production value. You are looking at a major development undertaking. As far as EDM- its pure marketechture. A robust workflow management system that integrates into Zope is currently not available. You should determine exactly what you need, what is available, and go from there. There are many systems that say they are "workflow" and do entirely different things( Verve and Vitria are an example ). Again what you are doing is likely to be a major development undertaking. Good Luck! -josh zeidner I am looking for a workflow (WF) linked to a electronic document management (EDM) system and a groupware email based (I have just happened to come accross aethera from the Kompany) that would be free software and preferably in Zope + Python. The WF+DEM system I am looking for need to be usable with only a browser (to be independant from the client ... that could be proprietary !), store its data into a postgresql database. It should be demonstrablable (at least showable into a proof of concept) within 2 weeks and be already installable and usable within 2 or 3 months. (I have obtained taoday that the date when we'll decide on the system would be postponed 2 weeks from wednesday 24/1 to wed 7/2) If I could find such a marvel, I may find the money to pay for it, at least 50000 $ to start with (this amount is a rapid guess; I may give more precise amounts we could spend in the following week) The idea is to use that combination of tools INSTEAD of buying a closed, proprietary solution (that may exist but be expensive and really har to parametrize), that NEED to be linked to a SAP ERP system. All suggestions and ideas are welcome, also on the selection criteria. (I happen to be responsible for the IT dept of the public institution that wants to buy such a tool, but be new in the place and do not yet know a lot about WF and EDM !) Soon I may be able to give you more details about the requirements. I don't think there is such as system polished and ready within 2 weeks. Here are some starting points: use wftk as a basis, the open source workflow toolkit -- http://wwww.vivtek.com/wftk use openflow, a Zope based, but stalled project, http://openflow.sourceforge.net use Chautauqua, an old python based workflow system, http://www.cs.colorado.edu/~carlosm/chautauqua.html use the old UCI Endeavors workflow (java) system at http://www.ics.uci.edu/pub/endeavors/endeavors.html We have not bit the bullet and built anything yet. Regards, Albert Boulanger aboulanger(a)vpatch.com _______________________________________________ Zope maillist - Zope(a)zope.org http://lists.zope.org/mailman/listinfo/zope ** No cross posts or HTML encoding! ** (Related lists - http://lists.zope.org/mailman/listinfo/zope-announce http://lists.zope.org/mailman/listinfo/zope-dev )

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Little Bug in 2.3 "new look"
by Joachim Werner 19 Jan '01

19 Jan '01

Hi! There is a little Bug in the new GUI: If you creat a new Folder that is empty, only "There are currently no items in foo" is displayed. So you can't import stuff before you have created an object in the folder. The import/export tab has also gone. Cheers Joachim.

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ANNOUNCE: Zope 2.3.0 beta 2 released
by Brian Lloyd 19 Jan '01

19 Jan '01

Hello all - Zope 2.3.0 beta 2 is now available. You can download it from Zope.org: http://www.zope.org/Products/Zope/2.3.0b2/ Highlights of the beta 2 release: - Changed the implementation of emergency_user to be backward compatible with the expectations of third-party user folders. All third party user folders should now work with Zope 2.3 without modification. - Zope is now much more tolerant of dependency problems in ZClasses. Some people were experiencing problems porting Products to upgraded Zope sites when their products contained ZClasses derived from base classes in other products (which may or may not have been installed on the new site). Zope is now much smarter about managing and recovering from failed base class dependencies and will re-register broken ZClasses when the missing Product causing the problem is installed. - Fixes for several other (more minor) bugs reported from beta 1 For more information on what is new in this release, see the CHANGES.txt and HISTORY.txt files for the release: - http://www.zope.org/Products/Zope/2.3.0b2/CHANGES.txt - http://www.zope.org/Products/Zope/2.3.0b2/HISTORY.txt Brian Lloyd brian(a)digicool.com Software Engineer 540.371.6909 Digital Creations http://www.digicool.com

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How would I keep _v_* attributes from getting thrown away?
by John D. Heintz 19 Jan '01

19 Jan '01

Hello all, I am using ZODB along with CORBA to expose peristent objects. Some of my objects have per-connection/session state. The clear example is file-like objects - effectively exposing persistent StringIO objects through CORBA. The issue is that I want multiple clients to be able to read() iterate over the same file-like corba objects. My initial idea is to have a _v_position attribute that is unique for each Connection cache object and maintains the correct position in the StringIO for each session. I obviously wouldn't want this to be a persistent attribute because a spurious commit would put it into the db and mess up any other users iterating through the same object from a different session. A volatile attribute, _v_position, however can be destroyed at any time with a cache cleanup via deactivate() call. How do I maintain volatile, but per connection stable, attributes on persistent objects? I thought about overriding the _p_deactivate() method, but I am also defining the __call_method__() hook and am bound by Bug 1783 that prevents this kind of thing. My thoughts on building this into cPersistent.c after looking through the code is to provide special processing to not remove some special attributes that also don't get saved into the db. Two ideas come to mind for this: 1) define _vs_* as volatile stable that is neither persisted nor clear()ed. This would slow down the deactivate() method though. 2) define _v_stable as a special volatile that doesn't go away. This would be quick processing in deactivate() and could be a dictionary to account for many stable volatile attributes. Thanks for any help, John -- . . . . . . . . . . . . . . . . . . . . . . . . John D. Heintz | Senior Engineer 1016 La Posada Dr. | Suite 240 | Austin TX 78752 T 512.633.1198 | jheintz(a)isogen.com w w w . d a t a c h a n n e l . c o m

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Re: CSS file serving
by Adrian Hungate 19 Jan '01

19 Jan '01

From: richard(a)bizarsoftware.com.au > >I've ended up hacking a version of special_dtml / ClassicHTMLFile that >serves up CSS. Has anyone got a better way of doing it (that detects >changes in the file and serves it up with the correct Content-Type)? > > Richard Try my ZStyleSheet product http://www.zope.org/Members/haqa/ZStyleSheet It will read your static CSS file, and allows for (IMHO) a much more logical view of the CSS. It also allows browser base branch exclusion - Removing sections from the sheet that will malfunction on a particular browser. Adrian...

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