August 2002 - Zope - Zope lists

Prevent recursive and multiple URLs in Zope
by Urs van Binsbergen 10 Aug '02

10 Aug '02

Hi Zope I am quite new to Zope and it is fun ;-) There are however 2 things about it I do not like very much: 1) URL trailing slash handling: http://example.com/some_doc http://example.com/some_doc/ are both valid URLs to access the method or document some_doc in the given root folder. In file-based publishing (like with apache) the second URL would be invalid, because some_doc is not a folder. http://example.com/some_folder http://example.com/some_folder/ are both valid URLs to access the folder some_folder in the root folder. Apache would allow the first URL, but would redirect to the second, because some_folder is not a document, it is a folder. 2) recursive acquisition: http://example.com/some_folder/some_folder/some_folder/some_folder/ is a valid URL to access the folder some_folder in the root folder. --- WHY do I dislike these two things? a) Philosophically: As the name "UNIQUE resource locator" already says: it is generally not good to have the same content available via different locators. b) Technically: Working with relative links becomes unreliable and dangerous. Problem #1 causes a relative URL to sometimes work and sometimes not work, depending on whether the visitor accesses "foo/bar/" or "foo/bar". Problem #2 makes relative links to be the door to infinite recursion. A simple link like "<a href="foo/">clickme</a>" will be the trap, where tumb spiders will loose themselves in a infinite loop (this was discussed shortly on this list under the subject "htdig indexing problem". --- Experiences? Since there are lots of Zope sites out there and I did not find big discussion on this matter until yet, am I maybe putting too much weight on it? --- Workarounds I still hope to find a relatively simple solution to change that behaviour. I did however only find some workarounds until now: - avoid relative URLs - work with absolute_url(), URL0, URL1 etc. instead - work with <base href=...> If my editors where all technical guys, this would be a solution (but there is still Murphy's law...). But as I know my editors, they just type something in as the link and test whether it works - and because it DOES work, they do not notice that they just opened the door to infinite recursion ;-). Other workarounds I was told: - (for problem 2): put an access-restricted subfolder with the same name into any folder - (for problem 2): disallow access to any some_folder/some_folder combinations in a robots.txt But these seems very tiresome and can only be automated with lots of work (or has somebody tried this?). -- Solution? Probably someone who knows the Zope-interna well would be easily able to create a plugin (product) which defines the following rules: - if the request-URL has a trailing slash, and the invoked object is not a folder: reponse 404 (even if generic Zope would serve an object then) - if the request-URL has no trailing slash, and the invoked object IS a folder: redirect to URL + '/' - if the acquisition path invoked by the request-URL contains multiple times an identical object: reponse 404 Does this make sense? I tried to do it using an Access Rule with SiteAccess2, but this doesn't seem to lead to a sensible solution, because an Access Rule is invoked when a folder is traversed FIRST, and in this moment it is not known which type of object the URL will call at last. So there should be something like an Access Rule to be called _at the very end_ of the traversal/acquisition process. I would be very thankful for any hint regarding this story, because it is really something that makes me a bit uneasy when starting to use Zope as my platform of choice for more complex and extended sites (which for all other reasons I would do, of course ;-) ). Kind regards, Urs ------------------------- Urs van Binsbergen van.binsbergen(a)taktik.ch bureau taktik GmbH Zentralstrasse 76b 8003 Zürich Telefon 01 450 34 05 -------------------------

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Why would YOU use Zope? ( or any other tool besides the 'industry standard')
by Heimo Laukkanen 10 Aug '02

10 Aug '02

This email is partly quest for finding arguments how to sell Zope and to understand how people - and especially people working in corporations IT departments - make any decisions and how could Zope fit into that picture. First a couple of words on my background, to understand my views. I've doing web development with different tools from 1996. Done little C and Perl, instantly adopted php when I saw it, got bored with Java when tried it years ago and everything was still a mess -- meaning you had to do everything yourself, fell in love with Zope. I have never built big corporate IT-systems or even managed one, my IT experience comes from applications that are either used through the web or talk with other applications with TCP/IP. I'm not a programmer - I'm just interested in solving problems. And now to the beef. Lately I've been reading some J2EE documents and tutorials and wondered about the promises that they give. Somehow it seems that there are answers or promises to almost anything, whatever you would like to do - there is answer of somekind available. Application services and frameworks are available on OpenSource flavour - or from IBM, Sun, Orcale and others. And people have really eaten the J2EE candy. Bookstores are filled with J2EE books and persons doing J2EE design work are paid pretty well by tech. companies like Accenture. Java and XML can be stated to be 'industry standard' - even in popular magazines. Microsoft architechtures seems also quite popular. My impression is that to many doing development on MS platform is a must because of the easy connection to office systems that also run on MS-tools. I once saw a nice web content management software that had a really nice tools into Word and also to desktop. Managing web content was as easy as writing stuff in Word. In this way I can easily understand those who have made 'safe' decisions on Java or MS way, either on choosing their platform or by buying products on that platform. Then again neither J2EE, Java webservices or ms-way of work haven't really felt good to me. Zope did touch some nerves and after a time it started to make sense. And after laerning a bit of Python Zope made more sense. It is not answer to everything, but doing rapid web development is really fun and fast with Zope. With Zope and Python I now know that I can do almost any webservice that our client can imagine, but on the other hand I also know that the same service could be done with any other development tool too. For a customer the Java platform seems secure. They have read about Java and know it as a term. They have an idea that if they buy Java, they can later on also find someone else who can continue the work done now and that way they would make a secured investment. They might have also something else allready running on Java-platform or are going to have, and don't want something to mix -- either because of it might cause more maintenance costs and / or they don't want to learn too many different things to handle. Same goes to MS platform, except that the products and solutions that they buy will be most likely a closed boxes that they need to trust (of course Java solutions can be that too). If we forget the price discussions, what are the arguments for choosing something else than 'industry standard'? How to make sure to a client, that their investment is secured and they have made a good selection for their web services. -- Heimo Laukkanen Oy Fountain Park Ltd Hämeentie 153 B, 00560 Helsinki, Finland tel. +358 9 777 68 161, gsm +358 40 759 1110, fax +358 9 777 68 100 http://www.fountainpark.org

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Feature request for metal - default macros?
by KevinL 10 Aug '02

10 Aug '02

Heya, Quick question: Is there a good way to set a "default" macro? What I'm trying to do is setup a situation where we call: here/blah/skins/helpfile/macros/?language Where ?language resolves to the current language in use. What I want to do is say "if the language selected doesn't exist, use english" - or, from the macro side, "if the macro specified does not exist, use this macro instead". Is that doable easily? Is it something that could be included as a feature in metal? (I know there's probably other ways to do languages specifically, but I thought the feature itself may be useful generically. And we're doing languages this way because we're giving clients cvs access to the skins dir, and it's a nice easy way to say "if you want to change this block of text on this page, edit this file", without descending into ZMI stuff.) KevinL

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How to implement a "join", can't add users via zpt or py
by Schlaegel 10 Aug '02

10 Aug '02

I need to let anonymous users join and create a username for themselves. I have scoured the archives and websites and not found anything that I can get to work. I am using zope 2.5.1. I have tried using both zpt and py. I tried container.acl_users.userFolderAddUser(name='viascript',password='password',roles=['User']) which gives an authentication error. and container.acl_users._addUser('viascript','password','password',['User'],0) which gives an invalid attribute name because it starts with "_" error Please help me here. I'm sure it must be an obvious answer for someone who has more experience than me.

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Get absolute_url of object with id that contains a dot in Script (Python)
by Eric Walstad 10 Aug '02

10 Aug '02

Hi all, How can I reference an object whos id contains a dot. I need to do this in a Python Script. e.g., in Script (Python): url = container.index.html.absolute_url() ---------------------^ That dot causes problems for me I didn't find the answer in the archives, so I'm asking here. Thanks, Eric.

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Zope Documentation
by Heimo Laukkanen 10 Aug '02

10 Aug '02

People, it is nice to see others contributing to the issue that there should be better documentation to support people learning and using Zope. I'm trying to do something to help those learning Zope, but would need help - others to contribute. First here are a couple of thougths and ideas: 1) I am in a situation where I have to make sure that others in our organisation will and can take Zope into use in web development. 2) I have seen that in the community there are a lot of good tips and guides scattered around and sometimes even lost 3) Zope Book is the best to this day, but there is a possibility that it is too much for some people - for the beginning. After they have the need and interest, they will and want to go through the Zope Book. With these thougths I have started a project, where I will make a set of tutorials that will guide a person from the beginning to setting up their own development enviroment and doing their own sites with Zope. I am trying to avoid writing about invention of the wheel again, but to reference to information available - and over and over again to the Zope Book. My wish and hopefull thinking is that this 'do it yourself' path would help people to get to a stage of understanding, where they are ready to find more and more information by them selves - and are a bit closer to seeing the Zen behind it all. Now, I NEED HELP. I am not an author and I don't write that good english. Also I don't know everything and would not like to write something that helps people to learn bad habits. I want to see that other people - newcomers - would see and get what is cool in Zope. If you can write something, throw in ideas or just be a good sport and bitch about grammar -- then help: http://www.zope.org/Members/huima/tutorials/FrontPage -- Heimo Laukkanen Oy Fountain Park Ltd Hämeentie 153 B, 00560 Helsinki, Finland tel. +358 9 777 68 161, gsm +358 40 759 1110, fax +358 9 777 68 100 http://www.fountainpark.org

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Re: [Zope] My Way of Zope Programming
by Terry Hancock 10 Aug '02

10 Aug '02

I was a little perplexed by this assertion: From: Jim Penny <jpenny(a)universal-fasteners.com> > This is the sales pitch. I wish Zope Corp would get over it! The real > benefit of ZPT, even for "non designer" sites, is that path expressions > make it much easier to use the same form for entry and error handling, > in a fairly readable manner. That is, DTML design encouraged a model of > present initial form; error check; (present error form or handle). > > ZPT encourages a view of present initial form; error check; (re-present > form or handle). Are you sure? It seems to me that this is not particularly dependent on the choice of DTML vs ZPT. What I do with DTML/Python is have 3 objects: Prototype Product myformLogic (Python script / Python method) myformForm (DTML method / DTMLFile method) myformAction (Python script / Python method) Typically, myformLogic is called from the top of myformForm (in a dtml-let), and computes a set of parameters, which are then displayed in the DTML form. The form posts to myformAction, which interprets the result. On a reject, the original form is called, which queries myformLogic again to recover state. The state is usually stored in hidden form elements or in the REQUEST. If an error condition exists, the Form object has a dtml-if to render an appropriate error message. By putting this analysis step into myformLogic, I avoid having overly complex DTML in myformForm, which can then be focused on having a good interface/layout for the user. But then, I haven't tried ZPT, so I'm not sure I get what you really meant. But the model above seemed very natural, and I tend toward using it more and more. Of course, if the form is extremely simple, you can just put the Logic in a python expression inside the Form, and avoid having a third object. > This make it easier to evolve the site, since you don't have to maintain > two different forms in lock-step. > > Yes, I am aware that the same could have been done in DTML. But placing > datasource logic in DTML tended to quickly devolve into a unreadable > morass, so that it was easier to maintain two separate methods. Hence the use of a Python script. Not sure I understand the point being made. Cheers, Terry -- ------------------------------------------------------ Terry Hancock hancock(a)anansispaceworks.com Anansi Spaceworks http://www.anansispaceworks.com P.O. Box 60583 Pasadena, CA 91116-6583 ------------------------------------------------------

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calling a DTML-Method in an Extended Method
by Dirk Hoeveler 10 Aug '02

10 Aug '02

Hi, I am trying to 'mirror' an existing zope application and put the files on an apache (don't ask, why, the customer wants it). Because I use a lot of ZClasses where put Images into, I cannot just use wget --mirror, because it cannot put pictures into a file. So I tried to build an Extended Method, which uses a ZopeFind for all the pages I need and tries to write the rendered pages on my disk. But I cannot render the DTML-Methods into a string, so that I can write a file. I tried something like myPageString = myFolder.index_html(), but i get the key error message about standard_html_header not being available. I see, that the script tries to render my index_html DTML-Method, but it doesn't seem to get the other DTML-Methods which are used in index_html. Can you give me hint, how to pass the context, namespace, everything it needs to my Extended method? By the way, if somebody knows of a Product, so already exists and produces a wget-like copy of a zope-site, that would also help a lot. Thank You, Dirk Höveler

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zope intranet development
by Kevin Sullivan 10 Aug '02

10 Aug '02

Hi, I am fairly new to the Zope world, but have chosen to undertake development of our department's intranet. We have been evaluating zope for some time now and toying with the CMF and plone. It seems that these tools are overly complex for what we need. We have no need for any sort of membership, simply just authentication and some degree of content ownership will suffice. For this we have chosen to build something more from the ground up. First, are there any simple tools that will help us to implement these goals? Also in starting to build the site, I am faced with choosing DTML or ZPT, any ideas on which is best for this type of project? I feel like I need a starting point in how to develop this project. I have a stack of zope and python book in front of me, along with numerous web resources, but don't know how to approach the overall design of this project. Any help would be greatly appreciated. Thanks in Advance, Kevin Sullivan Systems Administrator MIT Economics Dept

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RE: [Zope] Newbie questions: Calling PageTemplates from Python, a nd getting meta-info on ZSQL method results
by Leeuw van der, Tim 09 Aug '02

09 Aug '02

Hi, This page contains some very useful info. I have a question now about the contents of the data_dictionary in the resultset: Is there any indication whether a field is regarded a primary key by the database? Is there a non-database-specific way to find this out? I would find it quite useful to know this info. With regards, --Tim > -----Original Message----- > From: Maik Jablonski [mailto:maik.jablonski@uni-bielefeld.de] > Sent: donderdag 8 augustus 2002 15:48 > To: Leeuw van der, Tim; zope(a)zope.org > Subject: Re: [Zope] Newbie questions: Calling PageTemplates > from Python, > and getting meta-info on ZSQL method results > > > Leeuw van der, Tim wrote: > > 2. How can I find out the fields which are in the resultset > of a ZSQL > > method, using either Python or PageTemplates? > > hi, > > have a look at http://www.zope.org/Members/spinwing/ZSQL_Results > > cheers, maik > -- > Maik Jablonski __o > www.zfl.uni-bielefeld.de _ \<_ Deutsche Zope User Group > Bielefeld, Germany (_)/(_) www.dzug.org >

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