September 1999 - Zope-Dev

Fw: [Zope-dev] wygiwys
by morton＠dennisinter.com 20 Sep '99

20 Sep '99

----- Original Message ----- From: damien morton <morton(a)dennisinter.com> To: Jeffrey Shell <Jeffrey(a)digicool.com> Sent: Thursday, September 16, 1999 6:55 PM Subject: Re: [Zope-dev] wygiwys ----- Original Message ----- From: Jeffrey Shell <Jeffrey(a)digicool.com> > > If the community were to come up with something REALLY good, we'd be > interested. But there's a lot of difficulty matching the advanced > philosphies of Zope (Acquisition, Security, and now ZClass based > objects) and DTML (namespaces, syntax, general concepts) with just about > any visual editor out there. A _LOT_ of difficulty. It would be a > project of some serious effort, and we haven't seen anybody with enough > initiative to come up with a plan of tackling this. > > On the other hand, the new syntax is easier to work into smart > (non-visual) editors like Alpha (and Emacs-ish editor on the Mac) with > syntax completion and all that. Some tags like the contributed dtml-let > tag may have some difficulties in these environments that prefer to help > keep code very neat by quoting all attributes (a good thing really), > since the dtml-let tag behaves differently (ie, > > <dtml-let bob=uncle lu="aunt()" billy="'cousin'"> > > ) The basic problem is that most good html designers (as opposed to html hackers) are working with object oriented design tools. They whack this object there, set its properties, attach some behaviours, and away they go. They are working at the DOM level. Many of the objections to integration object oriented html desitgn tools with programmer oriented tools such as zope arise from the fact that programmers like to work with the raw text of the html. But the raw text is just the transport layer. Whats really being handed around in a http transaction is DOM trees that happen to be represented as html. If our work as programmers focussed less on whacking out html text and instead focussed on producing and consuming DOM nodes, then the integration between object oriented html design tools and out programming tools would become a lot easier. In fact, the a website as a whole could be viewed as a DOM structure, and there are many advantages to this. For example, if we assumed that our programs elemenst were functional DOM consumers and producers, you could eliminate much of the dynamic nature of a website. In my experince, there is a whole lot of stuff about a website that only changes slowly - it doesnt need to be re-created for every page view, only when the source data changes. If you could decompose a website into a kind of feedforward dataflow machine and add some intelligent caching, you would have a very efficient dynamic website. What would be needed for that would be for the programmed part of the website to conform to functional or dataflow programming - each module or function would take objects as input and would create or modify existsing objects. Might mesh well with the ZODB mechanism. > And there's always problems with this perrenial favorite (dtml tags > inside of HTML tags) -- > > <tr <dtml-if sequence-index-even>bgcolor="#c0c0c0"</dtml-if>> > > And, well, a trying-to-be-SGML-complient editor that is doing all these > wonderful things to help you (syntax hiliting, completion, dialog boxes > with tag attributes) panics and jumps over these. > > But situations like that aside, the new syntax is significantly easier > to work with. And with FTP and WebDAV integration, authoring outside of > the management interface is made a little bit easier (but work still > needs to be done in this area to help it along). > > So, the dream lives on... :) > > _______________________________________________ > Zope-Dev maillist - Zope-Dev(a)zope.org > http://www.zope.org/mailman/listinfo/zope-dev > > (To receive general Zope announcements, see: > http://www.zope.org/mailman/listinfo/zope-announce > > For non-developer, user-level issues, > zope(a)zope.org, http://www.zope.org/mailman/listinfo/zope ) >

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Re: XML Document & ZCat
by Clint Shelby McCulloch 20 Sep '99

20 Sep '99

It appears that zcat limits the acquisition of properties to direct children (not XML Document) when indexing. Example: 1) Create afolder with a property named, say, 'city' 2) Create a subfolder (subfolder1) 3) Create a subfolder of that folder (subfolder2) 4) Use ZCat to index the colection: in the expr field enter 'color' Result: The root folder and subfolder1 will be found and indexed, but not subfolder 2. Is this intended?

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using persistent storage inside Zope
by Adam Feuer 20 Sep '99

20 Sep '99

zope folks, if this has already been covered somewhere, let me know-- i just couldn't find information about it on the Zope site! i'm building a Zope product that needs to store some persistent information in the Zope object database. the information needs to be accessible to all instances of that product. my approach was: write a class that derives from Persistence.Persistent that will store the data and mediate access to it. then, in the product's __init__.py file, instantiate this class and put the instance into the Zope object database, then call get_transaction().commit() to commit it. theoretically, once my instance is in the Zope object database, other objects can access it-- adding or subtracting data. and the instance will handle committing its own changes, so it won't forget anything between restarts of Zope. my question: how do actually do this?? :-) i found a kludgy way to store a class instance in the Zope object database from the product's __init__.py file, but i can't figure out how to connect to this object from a random instance of my product. amy i going about this all wrong? is there a better way of storing and accessing persistent objects from inside of Zope? or if my approach is correct, how do actually implement it? here's what i am doing in the product's __init__.py file: # get the ZODB root-- kludge! root=context._ProductContext__app._p_jar.root() # now make the object instance if we need to if root.has_key('FooObject'): print "FooObject already in DB" else: print "made new FooObject." root['FooObject'] = Foo.Foo() get_transaction().commit() the problem seems to be, i don't know how to get access to the Zope object database's root object from inside an instance of my product. what i want to do inside the product base class, during an add or delete of an instance of the product, is something like: # somehow get the root of the Zope ZODB :-) root=Somehow.get.ZODB.root() root['FooObject'].remove_item(someitem) get_transaction().commit() any help is greatly appreciated! cheers adam -- Adam Feuer adamf(a)pobox.com

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XML Document & ZCat
by Clint Shelby McCulloch 20 Sep '99

20 Sep '99

I've made some progress trying to catalog xml documents.. There are a few wrinkles which make things interesting. One thing I've noticed, however, is that acquisition works somewhat strangely either when xml documents and zcat are combined or simply with xml documents. Element attributes appears to travel down the hierarchy only one level: if an element has an attribute then it will be availble only to its first children. This seems to be true with any properties of the xml document itself as well. This has been my experience cataloging xml documents, but I may try to see if the same is true with dtml. All in all, though, I'm very impressed with both of these products. Although I've yet to try it, kudos for adding relevance ranking!

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How??
by Junior 20 Sep '99

20 Sep '99

Can I Create function in ZOPE. (like javascript - function thisDate()) Liart Junior

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ZServer has wrong ZOPE_VERSION
by Robin Becker 19 Sep '99

19 Sep '99

the ZOPE_VERSION determined in ZServer/__init__.py is always '(unreleased version)' as ZServer is imported by Z2.py before SOFTWARE_HOME is set up; this means that status getting functions which make use of ZServer's ZOPE_VERSION always report the wrong version. The simplest fix is just to change ZServer/__init__.py to import FindHomes as well as version_txt ie at line 96 instead of import App.version_txt use import App.version_txt, App.FindHomes -- Robin Becker

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Y2K
by Will Fife 17 Sep '99

17 Sep '99

At my company, we are using Zope for our internal Web site, web app development, and are currently trying to get Y2K statements about all of the software that we use... I didn't notice any sort of having no Y2K bug statements on the site. If there is anything, on the site, and im just too blind to see it, could you please direct me in the right direction. Thank You

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Catalog relevance ranking
by Michel Pelletier 17 Sep '99

17 Sep '99

The catalog now does relevance ranking. If you search for an object and specify a TextIndex search term, the result objects returned will have two new attributes 'data_record_score_' and 'data_record_normalized_score_'. The score is the frequency of the search term found in the document. The normalized score is the score normalized between 0 and 1. This is a big plus, since the catalog now returns hits in essentially random order. If you do not specify a text index search term, 'data_record_score_' and 'data_record_normalized_score_' will both be set to 'None', so you can check for the precense of a score in DTML with <dtml-if>. Relevance ranking can be found in the CVS version of Zope. See CHANGES.txt (in the CVS) for more details. Have fun! -Michel

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Zope Site back on track
by Michel Pelletier 17 Sep '99

17 Sep '99

The new zope site is back at http://www.zope.org/. Soon, the old Zope site will be back to http://www.zope.org:8080/. The security hole has been patched, and soon we will be making a 2.0.1 release. Further information about 2.0.1 will be forthcoming. I would suggest the EVERYBODY who uses Zope 2.0 upgrade to 2.0.1 whether or not they feel threatended by this security exploit. Other than the 2 line security patch, 2.0.1 is identical to 2.0. I would like to take this opertunity to remind everyone that PRIVATELY informing us of 'showstopper' security bugs is just good netiquette. This gives us an opportunity not only to analyze the problem and provide a quick fix (after all, it could just be *your* problem, and you'd be 'crying wolf'), it also prevents the widespread distribution of exploits before we have a chance to control the situation. If, in the future, community members discover/encounter security-related issues, please send an email to the newly created address: security(a)zope.org mailto:security@zope.org -Michel

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Zope vs. Microsoft Dev Days 99 - mini-report
by Brad Clements 17 Sep '99

17 Sep '99

Yesterday I attended an all-day Microsoft Windows 2000 ra-ra event called Developer Days 99. It was pretty much what I expected, though there were some useful ideas/concepts that might be applicable to Zope. The track I attended focused on COM/OLE and XML. 1. In Windows 2000, MS has extended the concept of web-server load balancing to include COM object load balancing. You can combine multiple Windows 2000 machines into a COM "pool". When creating a business COM object, the pool manager creates the object on the first available/least loaded system. On the backend, multiple machines are running SQL 7 in a distributed manner. This gives a three tear approach (actually 4 if you count the client). Note that Microsoft encourages developers to encapsulate the business logic of an app into a COM component. This allows the component to be used by WIn32 apps, and by ASP web pages. The web pages only serve to present the data, they don't handle any of the logic: a. multiple web servers load-balanced by the router, each server runs IIS 5 with ASP b. multiple "business logic" COM servers instantiating objects to process requests made by the ASP pages c. multiple back-end SQL servers handling requests from the COM servers. Of course all of these layers could run on one physical machine, but Windows 2000 is supposed to make it easier to split up the processing if you want to. How does this apply to Zope? DC has a commercial product which I think applies to multiple web servers talking to a single ODB3, but I'm not sure exactly how that works. Since DTML methods/documents are not really Objects, I can't see a direct correlation with the "business logic" server aspect. However, the idea of seperating "business logic" from "presentation" sounds good. Presumably Python methods represent "business logic" and dtml methods are the presentation layer. Making it easier to use "external procedures" might be a big win (no flames on PythonMethods vs. External Methods, ok). 2. Tracking Session state for web users. By session, I mean remembering what the user has selected/set as properties between web requests. The example they used was a purchase order application. When adding a line item to a PO, the current PO number was saved as a session variable. Although not specific to Windows 2000, one technique they demonstrated seemed interesting. Variables or properties specific to a given session were packaged up into a COM Stream object (think of it as a pickled dict) and saved to an SQL server. Later requests used a cookie to retrieve the associated session information from the SQL server, unpack it and use the saved properties. Going back to item 1 above, using a back-end SQL database was the only way to save session properties because multiple web servers were handling the web requests. Hence the only common location for all of the servers was the back-end SQL. How does this apply to Zope? Someone could create a package that allows for quick and easy storage of session properties to a backend DB (perhaps using a DB Connection of some kind). Session retrieval could be via cookie, or using the URL insert method mentioned previously on this list. Using an external DB makes it easy to support multiple web servers (if they use the same backend database) for load balancing. A non- transactional ZODB3 would also be useful, but perhaps not available for load-balancing.. There are two ways I can think of to use such a product. <dtml-with>, which is explicit, or implicitely pushing the session dict into the namespace stack. The question of which comes first, REQUEST, or session dict, would be important. Another other issue is how to clean out old session objects from the database using ZCron.. Thoughts? 3. XML and OLE DB ADO 2.5 (apparently only available with Windows 2000 they said) can now export and import XML. They demonstrated using MS's XMLDOM component in conjunction with an ADO recordset (the result of a select). The ADO recordset now has a GetText and PutText function which exports/imports XML. By passing an XSL sheet to the XMLDOM component, the ADO XML output could be massaged for the target client. For example, IE5 clients got pretty much the raw XML, whereas non-XML capable clients got basic HTML. I haven't looked at the Zope XMLDocument, but ADO's built-in support of XML to represent data sets seems compelling. For example, could a ZClass property sheet have a GetXML or PutXML feature? Would that make sense? ZODB knows how to pickle objects and restore them. Seems to me that ZODB might also be able to represent python objects in XML. I'm not sure how this would be useful, but you could imagine creating a python class that consists of just data members, and being able to easily get it as XML. I think the dtml record feature addresses this for HTML.. Without data type information, XML'd python classes will be tough... 4. Finally I saw something interesting for Zope. IIS 5 has two new features. Server.Execute, and Server.Transfer The first, Server.Execute, allows an ASP script to be called "as a subroutine". We have this now with Zope, its very easy.. <dtml-var ...> The second, Server.Transfer, allows an ASP script to pass control to another script on the same server without using a redirect. This one seems interesting and the idea might be applicable to Zope. Basically it performs the same action as RESPONSE.redirect(), but does not send the redirect to the client. This is useful when you want to render a different page after processing a form, for example, but want the rendering of the second page to look like a new request from the user, without forcing the client to actually perform the redirect. This improves the response time for the client. I looked at HTTPResponse, and it looks like redirect() really sends the redirect back to the client. I didn't see an obvious function, like localredirect()... Perhaps using the new RETURN tag would work, but I don't think that starts a new transaction. You could imagine an "add" form that updates a database, then wants to redisplay the master detail page. If the "add" form redirects the client to the master detail page using something like the return tag, if the master detail page generates an exception, the add will be rolled back because its part of the same transaction. Right? I think a function like RESPONSE.localredirect() would be handy. It would accept URLs that only reference the local server. Internally it would complete the current transaction, then "fake up" a new request from the client to the new URL, as if the client had actually requested the new URL. Of course, RESPONSE.redirect() could be made smarter, such that it would automatically do this for local URLs, but perhaps need an option to force a client-side redirect if desired. Thoughts? Brad Clements, bkc(a)murkworks.com (315)268-1000 http://www.murkworks.com (315)268-9812 Fax netmeeting: ils://ils.murkworks.com ICQ: 14856937

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