September 1999 - Zope

Re: [Zope] How to rotate the Z2.log log file
by Christopher Petrilli 17 Sep '99

17 Sep '99

> > I don't want that Zope does it for me, and a cron job is fine, but I > don't know how I could do it. If I rename the file, ZServer doesn't > create a new one, but uses the renamed (Apache does the same). But > restarting Zope is not a solution, too. Any ideas? What needs to happen is that you have to get Zope to close it's log files and reopen them. It doesn't (as with all UNIX software) track based on name, but on inode/fd map information. If you send Apache a SIGHUP it'll close and reopen them. ZServer should do the same, but it doesn't. This is a good patch opportunity ;-) Chris -- | Christopher Petrilli Python Powered Digital Creations, Inc. | petrilli(a)digicool.com http://www.digicool.com

1 0

RE: [Zope] DateTime adding not working
by Jeffrey Shell 17 Sep '99

17 Sep '99

> I want a date that is 14 days after today, and I tried  and I get a bad operand error. > > The source says that you can "a positive or negative number and a > date-time object may be added to obtain a new date-time object that is > the given number of days later..." Try "ZopeTime() + 14"

1 0

Wysiwyg and the merits of a webinterface - some considerations
by Rik Hoekstra 17 Sep '99

17 Sep '99

Once in a while the subject of wysiwyg comes up on the list, as it did in the last few days. TO summarize the discussion as I understand it: The main problem is that people want a wysiwyg front end for their Zope database/web environment. On first consideration this seems to be something very desirable especially for end users. The problem of content management in web applications is present in other web application servers as well. Therefore various wysiwyg environments have their own solutions for this problem. Just some examples I happen to be acquainted with: - dreamweaver makes a difference between editable zones and ineditable zones in html; - homesite can be taught to program html-ish extensions (CFML, ASP, dtml should not be to much of a problem) and - Frontpage does this a solution of the infamous mix of client and serverside elements (which results in an inpenetrable and unmaintainable soup) The wysiwyg approach also seems to have the inevitable consequence that all of these editors mangle your html in an inexcusable way - so what you get may not at all be what you want. There may be other examples which do, but I am not aware of them. Zope has some inherent features that make these solutions not adequate, as Michael Bernstein (I believe) pointed out. They have to do with the difference between rendered documents and source code. This is further complicated by the separation of code of and layout as a result of which al templates and logic tend to be in different documents than where actual textual content is managed. I have been contemplating this issue for some time now, because it is crucial in an academic environment in which all sorts of people with all sorts of abilities (not just designers but also 'just' students and teachers and secretaries) are going to be giving input to a website. Considering all I have come to the conclusion that a webinterface will be the way to go, at least for me. My considerations: - many students are using hotmail. They complain, but that is because of slowness and ads. The interface, even if it's nothing special, gives them no problems. - I have been looking closely at some web based learning frameworks lately (because I am building one in Zope). They all promise a complete management system for courses and learning material. Some are shareware or freeware and some are very expensive solutions. They _all_ have web based interfaces, and it seems to be no problem at all for teachers. SOme of them are difficult to use, but that's because of their closed nature and their bad organization (this in contrast to Zope). - browsers offer a familiar environment for almost anyone. They do not have to learn another interface if they are editing through the web - users/content managers only _have_ to edit content and not need to occupy themselves with other issues, which is actually a relief for many of them. Zope has the added advantage that it is very agnostic in the integration of file types (by which pdf, msword and powerpoint can be uploaded just as easily as web pages) The only issue at the moment is that the current management interface (while it is a pleasure to work with for developers) is not at all useful for non-developers. All taken together I do not thing there will be a solution in the direction of wysiwyg editors. Instead I would plea for the development of a toolkit for end user web-based editing environments, as I believe many of us are developing them at the moment. Is anyone interested? Ideas? Comments? Rik Hoekstra

3 2

Re: [Zope] contributed zclass
by Kevin Dangoor 17 Sep '99

17 Sep '99

-----Original Message----- From: Mike Pelletier <mike(a)digicool.com> To: kedai(a)kedai.com.my <kedai(a)kedai.com.my> Cc: zope(a)zope.org <zope(a)zope.org> Date: Friday, September 17, 1999 11:42 AM Subject: Re: [Zope] contributed zclass > I think sharing your hand-built ZClasses is a great idea. While there >is no facility _specifically_ for ZClasses on Zope.org, 'Software Product' >objects work just fine with any kind of software, including ZClasses. In >fact, ZClass-based Products are smart enough to package themselves up into >a single file for distribution. See the 'Distribution' management view of >your Product. It seems easy enough, but for some reason when I use the Distribution tab for KM|Net News I get a 19K product.dat file in the appropriate directory, but the product is completely empty and I'm unable to add "KMArticleStore" objects. That's why I've been distributing it as an Export... Is there something silly I'm missing? I didn't think so, because all of the objects are selected in the Distribution tab. Should I submit this to the Collector? Kevin

1 0

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

4 3

Sorting catalog reports
by Chris Fassnacht 17 Sep '99

17 Sep '99

How do you use the sort attribute in a <dtml-in catalog> statement for a Zcatalog search report? I tried using <dtml-in catalog size=50 start=query_start sort=sortkey>, where sortkey is an input value from a Zcatalog search form that provides the name of one of the properties to sort on, but I get an AttributeError on sortkey. It works fine if I just enter the property name (e.g., id), and I get a true condition when I try <dtml-if "REQUEST.form.has_key('sortkey')"> and I can print out the value correctly, so I know the value is making it from the search form. This is probably one of those variable formatting syntax gotchas that I (as a new user) am missing. It'd be nice if I could find a detailed syntax for variable expression. You know, something that tells you when to use _[] or _[_[]], and what type of quotes (' or ") to use and when. Does something like this exist, or is it just Python syntax (meaning I should pick up a Python book)? Thanks. Chris Fassnacht

2 2

RE: [Zope] How to rotate the Z2.log log file
by smoerk＠gmx.de 17 Sep '99

17 Sep '99

>> How could I rotate the Z2.log log file? > >Manually. The software does not yet support log rotation. of course >you could impliment this functionality and send us a patch. ;) I don't want that Zope does it for me, and a cron job is fine, but I don't know how I could do it. If I rename the file, ZServer doesn't create a new one, but uses the renamed (Apache does the same). But restarting Zope is not a solution, too. Any ideas? Oliver

1 0

RE: [Zope] dtml-in and batches
by Michel Pelletier 17 Sep '99

17 Sep '99

> -----Original Message----- > From: Michel Pelletier > Sent: Friday, September 17, 1999 12:00 PM > To: 'Duncan Booth'; Michel Pelletier > Cc: 'zope(a)zope.org' > Subject: RE: [Zope] dtml-in and batches > > > > -----Original Message----- > > From: Duncan Booth [mailto:duncan@rcp.co.uk] > > Sent: Friday, September 17, 1999 12:20 PM > > To: Michel Pelletier > > Subject: RE: [Zope] dtml-in and batches > > > > > > I may be missing something obvious here, but if I use the > > in tag to > > > > iterate over a list in several batches, how can I easily work > > > > out what > > > > *all* the batches are. > > > > > > Get the _.len(ObjectValues(...)) and divide by your batch size. > > > > > > -Michel > > As I understand it, the last batch can be longer than the > batch size, > > but this solution won't cope with that. > > No batch will be bigger than the batch size. If anything, > the last batch will be smaller, but it will be the size of > the remainder of dividing the total result set length by the > batch size. Of course, this is only if you have 'orphan=0'. Otherwise the math is slightly more complex. There are gobs and gobs of batch processing variables. They are all documented in the DTML Guide. -Michel > -Michel

1 0

RE: [Zope] dtml-in and batches
by Michel Pelletier 17 Sep '99

17 Sep '99

> -----Original Message----- > From: Duncan Booth [mailto:duncan@rcp.co.uk] > Sent: Friday, September 17, 1999 12:20 PM > To: Michel Pelletier > Subject: RE: [Zope] dtml-in and batches > > > > I may be missing something obvious here, but if I use the > in tag to > > > iterate over a list in several batches, how can I easily work > > > out what > > > *all* the batches are. > > > > Get the _.len(ObjectValues(...)) and divide by your batch size. > > > > -Michel > As I understand it, the last batch can be longer than the batch size, > but this solution won't cope with that. No batch will be bigger than the batch size. If anything, the last batch will be smaller, but it will be the size of the remainder of dividing the total result set length by the batch size. -Michel

1 0

SSI???
by Francisco Sam Castillo 17 Sep '99

17 Sep '99

Hello, I have a doudbt is it possible to do Server Side Includes from external HTML with zope?, The situation is this, I have an application made in perl that captures and analizes data and then it outputs results in the form of static html, this application is all ready to complex to port it to dtml so I was wondering if it would be possible just to call in the static content and join it to the zope site much as SSI work on apache, again is it possible? thanks a lot in advanced Sam

2 1