December 1998 - Zope

- title property
by Pavlos Christoforou 14 Dec '98

14 Dec '98

Zopoi I just started to play around with Zope and I came across the following problem. I created a document and by mistake I deleted the title property. After that, adding new properties somehow went unregistered and I was not able to add the title property back. Am I missing something obvious? My mind is still a bobo app Pavlos

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- Q on product development
by Janko Hauser 14 Dec '98

14 Dec '98

So, one step further, with the new Beta everything went fine. Started to build a new product. Outline: Want to build a Gallery, where owners can add postscript-pictures with some comment. A thumbnail is generated and a page with thumbnail and comment is displayed. The thumbnail is a link to the actual Postscript picture. A Gallery can include other Galleries to collect pictures for different topics. This will be a subclass of a Folder. As this product should be used by many different users, I don't want to fill up the database with all this pictures. So I want to make an object, which acts like a file, but stores only a link to an external file. Subclassing File and overwriting PData -> ready is the BLOB. Q1: Is there already something like this in Zopeland? This could also be used to make dataviewers for big (GB) datafiles. Q2: I can delete the object from the POS, but how do I delete also the external file? Is there some hook I can use? Q3: The development of a package is quite time consuming, because I need to delete the product, restart the server and add the object again. Can this be done faster? How are other people developing packages? Are all writing bug free code :-)? Q4: Would it be easier to build soemthing like this as external methods? I see now, that it is easier, but than I need to implement my own upload scheme and so on. (This are some of the benefits of a product, all the predefined protocolls, right?) Q5: If I want to extent the gallery with some functions, can these be coded as external methods and added to the Gallery object? I have tried it, but a BLOB object, which is only one class of the product does not get the method (defined by def method(self,...): ) Q6: If more and more packages are developed the security screen becomes rather big. How will this be handled in the future? Thanks for any help and insight you can provide __Janko Hauser

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- Experimental 'External Objects' Product Available
by Amos Latteier 14 Dec '98

14 Dec '98

Fellow Zopistas: Despite the fact whatever Jim Fulton may think about the merit of the idea, I wrote a first cut at a Zope Product that allows you to plug normal Bobo objects into Zope. It is basically a slightly hacked version of External Method which I am calling External Objects. You can get it at: http://www.zope.org/Download/Contrib It is only lightly tested, and should not be considered official. However, it does seem to let you more or less plug existing Bobo modules into Zope. To use it download the tarball. Ungzip and untar it in your Zope directory. Now shutdown and restart Zope. Now you should have be able to create External Objects. To create an external objects object, proceed like you are creating an external method. Copy your module to either 'Zope/Extensions' or 'Zope/lib/python/Products/SomeProduct/Extensions'. Your module should define some toplevel Bobo objects. Now create the External Objects object. Specify your module name and the names of the objects you want to use. The list of objects should be space delimited. That's it. Now you can access your Bobo objects as attributes of the External Objects product. Notes: If your objects use Acquisition, they will be correctly patched in to the Zope object hierarchy. If your objects use BoboPOS, you should not/cannot store your objects in Zope's object database. I'm not sure what the right thing to do here is... There may be a good solution to this problem, I just haven't though the issue through at all. This is just an experiment, and I only wrote it because I suggested it and no one else seems to have written it yet ;-) Have fun. -Amos

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- What constitutes a transaction?
by Ty Sarna 14 Dec '98

14 Dec '98

I'm obviosuly missing something here. I have a product, a subclass of Folder. It has several methods that do things to its internal state. Some of these methods cause a transacton to be generated (Ie, when adding or deleting objects, setting properties, etc., the method shows up in Undo). When I shut down zope and restart it, these changes are still there. My added methods have effect that is forgotten at shutdown, and they don't show up in the Undo list. I have another Product where my added methods do work correctly. What am I missing?

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RE: [Zope] - What constitutes a transaction?
by Paul Everitt 13 Dec '98

13 Dec '98

Ty wrote: > and restart it, these changes are still there. My added methods have > effect that is forgotten at shutdown, and they don't show up > in the Undo > list. I have another Product where my added methods do work correctly. If the things that you change aren't Persistent, then the transaction manager isn't notified that state has changed. For instance, if you're method changes an attribute that is a standard Python dictionary, then the transaction manager doesn't see it. --Paul

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- Zope, Win95, File Output
by Fabian Lemke 13 Dec '98

13 Dec '98

Hi, I recently found Zope, and it looks very very useful. I have a few quick questions though.. I maintain a few different websites through work for various companies. Each of these sites have a few things that are very database oriented, though are updated about twice per month. Zope looks absolutely perfect for the design of it, though we have the problem of the ISP we are running the pages on probably wouldn't install Zope, and it's unfeasable to switch. My question boils down to this: Is there an easy way (accessing in python or whichever) to use Zope to generate the output HTML files instead of only through the webserver? We also use Frontpage 98 to do most of the editing, and if Zope can be accessed easily enough to do this I'll be itching to design FrontPage Components to make use of it. Thanks much!, Fabian

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Re: [Zope] - Image handling - avoiding chaos
by Brad Marsh 13 Dec '98

13 Dec '98

Aha! -----Original Message----- From: Paul Everitt <Paul(a)digicool.com> To: Brad Marsh <research4(a)snowcrest.net>; zope(a)zope.org <zope(a)zope.org> Date: Sunday, December 13, 1998 10:36 AM Subject: RE: [Zope] - Image handling - avoiding chaos > >Paul wrote: >There was a discussion here about a hundred messages ago about how to >handle this. Thanks for the info. I also remember the item on the list; I didn't have Zope running, and the discussion was completely ungrounded in reality to me. Now I wish I had paid attention. I'll look to the archives... Thanks again, Brad Brad Marsh, Computer Specialist Center for Evaluation and Research, LLC http://www.tchp.org/cer/

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RE: [Zope] - Image handling - avoiding chaos
by Paul Everitt 13 Dec '98

13 Dec '98

Brad wrote: > Do I have to scatter images around the folders? Or can I > organize them into > "images" subfolders and refer to them implicitly? There's good news and bad news. _If_ Image objects could handle it, you could do the following. Create a top-level folder called Images. Then, in any Document in the system, you can say:  Now, if you're image happens to have an ID that Python can't grok, for instance 'mylogo.gif', then that won't work. An easy alternative is:  Now that bad part. Zope will do precisely the right thing in the Document by calling the Image and getting its str representation, thus inserting: <img src="mylogo"> into your Document. Bad thing, though, is that the src is invalid -- it doesn't go into the Images folder. There was a discussion here about a hundred messages ago about how to handle this. Since I can't even remember yesterday, I don't recall the answer (something like teaching the Image tag to put its full path in what is returned maybe...) --Paul

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RE: [Zope] - Zope, Win95, File Output
by Paul Everitt 13 Dec '98

13 Dec '98

Fabian wrote: > I maintain a few different websites through work for various > companies. Each of these sites have a few things that are > very database oriented, though are updated about twice per > month. Zope looks absolutely perfect for the design of it, > though we have the problem of the ISP we are running the > pages on probably wouldn't install Zope, and it's unfeasable > to switch. Tell them its written in Perl. :^) > My question boils down to this: Is there an easy way > (accessing in python or whichever) to use Zope to generate > the output HTML files instead of only through the webserver? This has been talked about enough recently that I added it to my Q&A. What we need is some ambitious soul to write the 50 lines of Python to do this, hopefully as a Zope Product. > We also use Frontpage 98 to do most of the editing, and if > Zope can be accessed easily enough to do this I'll be itching > to design FrontPage Components to make use of it. Needless to say Zope would have to sitting behind a FP-compatible server for this to work, unless you just wanted to do FTP stuff. What did you have in mind for FP? --Paul Paul Everitt Digital Creations paul(a)digicool.com 540.371.6909

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RE: [Zope] - Httpdapy and Zope problems
by Paul Everitt 13 Dec '98

13 Dec '98

Andreas wrote: > > 1. Because Apache runs multiple processes, BoboPOS > databases will end up > That's why all publisher serialize it to ONE LRP. Currently. That situation shouldn't last more than two months. Honestly, many of the pieces have already shown progress: 1) BoboPOS3a1 was released. 2) We lined up Medusa, which is meant to form the core of our concurrency architecture. I know your answer is that Medusa isn't good for long-lived transactions, but if you have a pool of handlers matched to the thread pool in the application, people at least have the option of stating the number of concurrent operations. 3) Jeff has already made progress on concurrent PCGI and you have shown another fascinating technique for integrating with Apache. 4) Jim has had BoboPOS working atop SOLID for several months now. 5) We *finally* made the move to Python 1.5. Once we get the source release out of the way, Jim can get back to tying all these things together. January ought to be a good month for concurrency. > Not really. I've been using a pcgi published app with MANY > threads and it > works quite well :) Presumably on Linux, right? Want to share the details of your kernel versions, etc. and any lessons you learned along the way? --Paul

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