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Trying to design a PythonMethod Product
by Evan Simpson 12 Aug '99

12 Aug '99

I'm making a serious run at trying to create a Product which will allow through-the-web creation of methods written in straight Python. Right now what I've get is a pile of brainstorming, and I'd appreciate feedback. Basically, I plan to take an arbitrary chunk of Python code, wrap it in a function definition, compile it, and then thrash the resulting bytecodes with bytecodehacks (see http://starship.python.net/crew/mwh/bch/index.html) This will serve the dual purposes of enforcing restrictions on what the code can do, and bending the semantics for better Zope integration. Thoughts so far: 1. Must store a PythonMethod as raw text for editing purposes. Compile/hack on each load, or try to store the compiled function for speed? 2. Allow simple assignment, and no other kind. "x = anything" is legal, but not "x[0] = ...", "x.spam = ...", "x() = ...", etc. Tuple/list unpacking might also be allowed. 3. Disallow "del" and "exec" entirely. 4. Restrict "import" to modules/packages found in a particular location, so that 'safe' modules can be used. 5. Allow "while" and "for". Insert 'escape code' at the bottom of every loop, to allow PythonMethods to 'time out' after some elapsed time or loop count. 6. Allow "print" to be used to generate rendered output by replacing it with a function that accumulates text. If anything other than literal "None" is returned, the collected "print" text is discarded, otherwise it becomes the return value (on "return", "return None", and on implicit return, but not on "x=None; return x", for example). 7. Either disallow "global", or redirect access to globals into a controlled namespace. 8. Provide the Zope standard builtins (and tags?) as builtins. or-have-I-missed-a-showstopper-ly y'rs Evan Simpson

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presenting cookie-free shopping cart
by Josh Zeidner 12 Aug '99

12 Aug '99

here is the cookie free basket product. Also I attached a exported object that shows you how to use it. In addition, you must make a folder in the Shared directory called StoreSession and unzip the contents of also.zip into it. Basically the product is a folder that provides the following functions: addToBasket( productid, quantity, REQUEST ) - adds a quantity of an item to the basket getItems( REQUEST ) - gets a list of objects that show the products makeSessionLink( resource, REQUEST ) - creates a URL to another page in the basket session - one uses it like this <a href="">ANOTHER PAGE</a> - if you dont use makeSessionLink you will not preserve the session - have fun Josh Z _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com

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Minor quibble with the "let" tag
by Alexander Staubo 12 Aug '99

12 Aug '99

For programmers (like me) who like our syntax consistent, the inability to write <dtml-let foo = 1> (because spaces are not permitted around the equivalence operator) is annoying. I have to write <dtml-let foo=1> and that's just plain "ugh!" in my book. Can't something be done about this? Why not accept whitespace in the first place? Should be simple enough, shouldn't it (looking at DT_Let.py, I don't see exactly why not)? -- Alexander Staubo http://www.mop.no/~alex/ "He won a first at Oxford, squandered three fortunes, made love to a thousand women, imbibed strange drugs, sold his soul for Rock 'n' Roll, almost pipped Einstein for the Nobel Prize, was barred from every Chinese noodle parlour in West London and died penniless, at a Hastings boarding-house in his ninetieth year." --Robert Rankin, _The Book of Ultimate Truths_

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Re: [Zope-dev] Minor quibble with the "let" tag
by Anthony Baxter 12 Aug '99

12 Aug '99

>>> Alexander Staubo wrote > <dtml-let foo = 1> > <dtml-let foo=1> > > Can't something be done about this? Why not accept whitespace in the > first place? Should be simple enough, shouldn't it (looking at > DT_Let.py, I don't see exactly why not)? Won't this break the 'HTML-ish' nature of DTML? Can you do <tag name = value> in HTML? (I thought not, but I just tried it, and netscrape let it work. not that _that_ means anything...) Anthony

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Re: [Zope-dev] Zope SQL Query builder product?
by Anthony Baxter 12 Aug '99

12 Aug '99

>>> Jim Tittsler wrote > > check out www.interlink.com.au/~anthony/ > That yields a 404 Not Found error. to quote a popular advert here - "bugger". Try instead http://www.interlink.com.au/anthony/ Anthony, who should check his own URLs before posting. :)

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Re: [Zope-dev] Trying to design a PythonMethod Product
by Josh Zeidner 11 Aug '99

11 Aug '99

Isn't this the same as External Methods? -josh z >From: "Evan Simpson" <evan(a)tokenexchange.com> >To: <zope-dev(a)zope.org> >Subject: [Zope-dev] Trying to design a PythonMethod Product >Date: Wed, 11 Aug 1999 16:34:39 -0500 > >I'm making a serious run at trying to create a Product which will allow >through-the-web creation of methods written in straight Python. Right now >what I've get is a pile of brainstorming, and I'd appreciate feedback. > >Basically, I plan to take an arbitrary chunk of Python code, wrap it in a >function definition, compile it, and then thrash the resulting bytecodes >with bytecodehacks (see >http://starship.python.net/crew/mwh/bch/index.html) >This will serve the dual purposes of enforcing restrictions on what the >code >can do, and bending the semantics for better Zope integration. > >Thoughts so far: > >1. Must store a PythonMethod as raw text for editing purposes. >Compile/hack >on each load, or try to store the compiled function for speed? > >2. Allow simple assignment, and no other kind. "x = anything" is legal, but >not "x[0] = ...", "x.spam = ...", "x() = ...", etc. Tuple/list unpacking >might also be allowed. > >3. Disallow "del" and "exec" entirely. > >4. Restrict "import" to modules/packages found in a particular location, so >that 'safe' modules can be used. > >5. Allow "while" and "for". Insert 'escape code' at the bottom of every >loop, to allow PythonMethods to 'time out' after some elapsed time or loop >count. > >6. Allow "print" to be used to generate rendered output by replacing it >with >a function that accumulates text. If anything other than literal "None" is >returned, the collected "print" text is discarded, otherwise it becomes the >return value (on "return", "return None", and on implicit return, but not >on >"x=None; return x", for example). > >7. Either disallow "global", or redirect access to globals into a >controlled >namespace. > >8. Provide the Zope standard builtins (and tags?) as builtins. > >or-have-I-missed-a-showstopper-ly y'rs >Evan Simpson > > >_______________________________________________ >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 ) _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com

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ANNOUNCE: Zope 2.0 Beta 4
by Jim Fulton 11 Aug '99

11 Aug '99

Zope 2.0 Beta 4 is available for download at: http://www.zope.org/Download/Releases/Zope-2.0.0b4. See the release notes at the above URL for details. Jim -- Jim Fulton mailto:jim@digicool.com Python Powered! Technical Director (888) 344-4332 http://www.python.org Digital Creations http://www.digicool.com http://www.zope.org Under US Code Title 47, Sec.227(b)(1)(C), Sec.227(a)(2)(B) This email address may not be added to any commercial mail list with out my permission. Violation of my privacy with advertising or SPAM will result in a suit for a MINIMUM of $500 damages/incident, $1500 for repeats.

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Zope SQL Query builder product?
by Brad Clements 11 Aug '99

11 Aug '99

I thought I had seen an "sql query builder" type of product posted or announced within the past two months, but I can't find a reference to it. Am I going crazy, or can someone post a pointer to it? It allowed web user's to build up a query to generate a report, then save the query. Thanks 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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ZClasses comments and questions
by Martijn Faassen 10 Aug '99

10 Aug '99

Hi there, I'm unclear about some aspects of ZClasses. Imagine I have a ZClass 'A'. Instances of this ZClass have a 'messages' tab where various messages this ZClass can emit can be edited. It should look something like this: ________ ------|messages|------- Foobar reached 10 kelvin: --------------------- | Your Foobar is too| | cold, please heat | | it! | --------------------- Hyperdrive coils unwinded -------------------- | Wind up your | | hyperdrive coils!| -------------------- Where the boxes are textareas. The person who uses ZClass A can edit the particular messages that will be emitted for that instance. Now, I'm thinking about a class hierarchy where there's a ZClass B that inherits from A. ZClass B has the same messages as A, but may add a few. The 'messages' tab should automagically adapt to include the new messages. I'm having trouble finding the best way to implement this using ZClasses. One option is to use propertysheets. I may include a propertysheet 'Messages' in ZClass A. However, there is no easy way to get to that propertysheet in ZClass B. I may do it programmatically with DTML (add a property dynamically upon construction of a B instance), however, but it's far from ideal. Another problem with propertysheets is that there isn't a way to have object properties. My messages have already too many attributes, two; a title and the messsage contents. Properties have only an id and contents. Imagine I also want to add a 'criticality level' or whatever to my messages. I run into trouble with properties. Another idea I had was to make a special ZClass called 'message'. This message ZClass would have a property sheet with the title of the message, and the message itself, and criticality level if necessary, etc. The idea is then to add an instance of such a Message ZClass to my own ZClasses whenever I needed to add a message. ZClass A would implement a message tab that would automatically list all Message objects as textareas for editing (as described before). If ZClass B adds a Message, that message automatically show up in the tab. Apart from the fact that with the latest beta I still can't seem to add ZClass instances to ZClasses (I saw a report in the collector on this already), I wonder if this will work at all. Would the contained 'message' ZClass's properties be class attributes or instance attributes of ZClass A? That is, if I changed the 'Foobar too hot' message for one instance of ZClass A, would it change for all instances? That is not what I want. Some Zope Zen is still needed here to grok ZClasses fully. Am I trying to push them too far? Should I go for Python, and derive my ZClasses from a Python class? I would lose the easy way to add configurable messages (and other configurable stuff) to ZClasses that I had in mind, but in Python this isn't too hard. Responses to these musings and questions are very welcome. Regards, Martijn

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Re: [Zope-dev] Cookie-Free Shopping Cart
by Josh Zeidner 10 Aug '99

10 Aug '99

>Hi Josh: > >I am interested in checking out the code you are developing for a >cookie-free shopping cart. > >Are you planning on developing this into a full blown open source ecommerce >solution for Zope? There has been quite a bit of talk lately about an open-source e-commerce solution for Zope. Take a look at the Zope-Dev archives for this month( title : "The Birth of ZCommerce". Would you be interested in contributing? As for the shopping cart I have to figure out how to get the distribution to work with external methods( does anyone know how to do this? ). -Josh Zeidner _______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com

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