Re: [Zope3-Users] Can interfaces be mutated cleanly?
Am Donnerstag, 12. April 2007 17:22 schrieb Christian Theune: Hi, I didn't find anything in the documentation or google on this: I want to define an interface like: class IMySchema(zope.interface.Interface): pass Later, I want to use ore.alchemist which currently is able to take a SQLAlchemy table description and turn it into a new interface/schema. Interesting - is ore.alchemist the package developed by Kapil Thangalevu? If yes, is it working? I had the impression that the project is abandoned. I currently use z3c.zalchemy, which has, however no automatic generation of interfaces. I want to extend this code so that I can pass it an existing interface to modify it (update) with the schema definition. I need this so that the interface is: a) present in the code when reading it b) available for ZCML configuration (it's a problem for us right now because the database/SQLAlchemy stuff is setup up a little bit later after executing a couple of ZCML actions) This is a concept I was also thinking about but I'm unsure if it would really lead to architectural advantages: The DDL statements specify several constraints for the mapped object, such as: - Data Type - Maximum string length - Enumerations (check in) - not null/with default So it looks at first appealing to directly adopt them in the object's interface. However, there may be two caveeats: 1) Often, the interface definitions are stricter than the DDL-statements. For instance, the database could define a varchar(40), while in the interface, I'd rather limit the schema (and therefore an input field) to a length of 20. Or maybe I'd like to use a more specific datatype which can not be automatically deduced from the DDL-statements 2) All ends up with constraints in different locations - some are in the DDL statements, others are in the interfaces. So maybe this also leads to redundancy and complexity. Moreover, what happens if the DDL and interfaces are not being maintained by the same developer group? What if the database guys choose to extend some varchar from 40 to 400, a change which possibly propagates to the page layout? (longer input widget). Therefore maybe it's cleaner to define everything in the interface of the mapped object, regardless if this information is redundant. And then I'm thinking about some check function that tests if the DDL-statements and the interface definitions are conflicting or not - much like with interfaces, which only have contracts with objects (via implements()) and provide utilities such as verifyObject to check if they comply. Best Regards, Hermann -- [EMAIL PROTECTED] GPG key ID: 299893C7 (on keyservers) FP: 0124 2584 8809 EF2A DBF9 4902 64B4 D16B 2998 93C7 ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
On Thursday 12 April 2007 11:22, Christian Theune wrote: While looking into it, we found that interfaces do not offer a public way to modify the attributes they have, and modifying the internal data structures would be both evil and cumbersome. It is a violation of the interface contract that they can be modified. Any hints? However, work in this area has been done with persistent schema. Look for zope.app.schema; if it is deleted from the repos, look in older revisions. Regards, Stephan -- Stephan Richter CBU Physics Chemistry (B.S.) / Tufts Physics (Ph.D. student) Web2k - Web Software Design, Development and Training ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
[Zope3-Users] ZEO security examples
Hi, Maybe I'm wrong, but it seems that ZEO protocol is, by default, unauthenticated. I've read here and there a few references to an authentication mechanism which could be setup in ZOPE/ZEO, but can't find any valuable implementation example for Zope3. So, any link to define this for Zope3 would be very nice. Thanks for any help, Thierry Florac -- Chef de projet intranet/internet Office National des Forêts - Département Informatique 2, Avenue de Saint-Mandé 75570 PARIS Cedex 12 Mél : [EMAIL PROTECTED] Tél. : +33 01.40.19.59.64 Fax. : +33 01.40.19.59.85 ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] ZEO security examples
Hi Thierry. There is a basic means of authentication built in to ZEO but it is not terribly secure. You can read about it in the zeo source. You may wish to look as Fred's zc.sshtunnel package to help you secure your communication. Regards, David Thierry Florac wrote: Hi, Maybe I'm wrong, but it seems that ZEO protocol is, by default, unauthenticated. I've read here and there a few references to an authentication mechanism which could be setup in ZOPE/ZEO, but can't find any valuable implementation example for Zope3. So, any link to define this for Zope3 would be very nice. Thanks for any help, Thierry Florac ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
i would suggest some alternatives approaches to consider first. potentially this would be easier going the other way around with zs2sa, and generating the mapper from there, you don't need to annotations as well since the zope schemas contain the relevant ui metadata, and the schema is the canonical definition of the rdb/sa schema. bonus is you get multidb support for the schema, as an example of doing things this way, https://svn.objectrealms.net/view/public/browser/ore.member/trunk/src/ore/member/example2.py the transmute funcction has the options of specifying base interfaes, so you also have the option at the risk of ordering dependencies of replacing the iface class thats a base arg to the transmute function with the result of the transmute function, presumably though if this being done in the same module (interfaces.py) then its not an issue though. cheers, kapil On Thu, 12 Apr 2007 11:22:06 -0400, Christian Theune [EMAIL PROTECTED] wrote: Hi, I didn't find anything in the documentation or google on this: I want to define an interface like: class IMySchema(zope.interface.Interface): pass Later, I want to use ore.alchemist which currently is able to take a SQLAlchemy table description and turn it into a new interface/schema. I want to extend this code so that I can pass it an existing interface to modify it (update) with the schema definition. I need this so that the interface is: a) present in the code when reading it b) available for ZCML configuration (it's a problem for us right now because the database/SQLAlchemy stuff is setup up a little bit later after executing a couple of ZCML actions) While looking into it, we found that interfaces do not offer a public way to modify the attributes they have, and modifying the internal data structures would be both evil and cumbersome. Any hints? Christian ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
On Fri, 13 Apr 2007 02:36:07 -0400, Hermann Himmelbauer [EMAIL PROTECTED] wrote: Am Donnerstag, 12. April 2007 17:22 schrieb Christian Theune: Hi, I didn't find anything in the documentation or google on this: I want to define an interface like: class IMySchema(zope.interface.Interface): pass Later, I want to use ore.alchemist which currently is able to take a SQLAlchemy table description and turn it into a new interface/schema. Interesting - is ore.alchemist the package developed by Kapil Thangalevu? If yes, is it working? I had the impression that the project is abandoned. it is, and its working, its been in production since inception, has a number of features not present in the other sa zope integrations (schema generation, both from sa and from zope.schema, as well keyreference support, etc). unfortunately suffers a bit in that the formlib integration is currently targetting zope2/plone, but thats contained in a separate z2 product, as well as my own lack of time to promote it or work on new feature developmen at the moment. cheers, kapil ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
Am Freitag, 13. April 2007 20:27 schrieb Kapil Thangavelu: i would suggest some alternatives approaches to consider first. potentially this would be easier going the other way around with zs2sa, and generating the mapper from there, you don't need to annotations as well since the zope schemas contain the relevant ui metadata, and the schema is the canonical definition of the rdb/sa schema. bonus is you get multidb support for the schema, as an example of doing things this way, https://svn.objectrealms.net/view/public/browser/ore.member/trunk/src/ore/m ember/example2.py the transmute funcction has the options of specifying base interfaes, so you also have the option at the risk of ordering dependencies of replacing the iface class thats a base arg to the transmute function with the result of the transmute function, presumably though if this being done in the same module (interfaces.py) then its not an issue though. Interesting approach, however, I doubt this is going to work when one has to access an existing relational database - like in my case. After all one has once again redundant definitions. Therefore in cases where the database is designed together with the Zope3 application, the transmute function could be an interesting approach, but in cases where the DDL-statements already exist, the generation of schemas out of the table definitions seem to be the better way. Moreover I'm also curious if advanced table definitions such as constraints, checks and the like can be generated from Zope schemas. Best regards, Hermann -- [EMAIL PROTECTED] GPG key ID: 299893C7 (on keyservers) FP: 0124 2584 8809 EF2A DBF9 4902 64B4 D16B 2998 93C7 ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
Am Freitag, 13. April 2007 20:33 schrieb Kapil Thangavelu: On Fri, 13 Apr 2007 02:36:07 -0400, Hermann Himmelbauer [EMAIL PROTECTED] wrote: Am Donnerstag, 12. April 2007 17:22 schrieb Christian Theune: Hi, I didn't find anything in the documentation or google on this: I want to define an interface like: class IMySchema(zope.interface.Interface): pass Later, I want to use ore.alchemist which currently is able to take a SQLAlchemy table description and turn it into a new interface/schema. Interesting - is ore.alchemist the package developed by Kapil Thangalevu? If yes, is it working? I had the impression that the project is abandoned. it is, and its working, its been in production since inception, has a number of features not present in the other sa zope integrations (schema generation, both from sa and from zope.schema, as well keyreference support, etc). unfortunately suffers a bit in that the formlib integration is currently targetting zope2/plone, but thats contained in a separate z2 product, as well as my own lack of time to promote it or work on new feature developmen at the moment. Formlib integration is still something I'm struggling with. I'm currently setting up forms (filling with data) manually via SetUpWidgets. Hopefully I will be able to break this down on a common denominator, refactor it and provide some ORMFormlib library which inherits from form.Form, we'll see... Best Regards, Hermann -- [EMAIL PROTECTED] GPG key ID: 299893C7 (on keyservers) FP: 0124 2584 8809 EF2A DBF9 4902 64B4 D16B 2998 93C7 ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
On Fri, 13 Apr 2007 15:09:29 -0400, Hermann Himmelbauer [EMAIL PROTECTED] wrote: Am Freitag, 13. April 2007 20:27 schrieb Kapil Thangavelu: i would suggest some alternatives approaches to consider first. potentially this would be easier going the other way around with zs2sa, and generating the mapper from there, you don't need to annotations as well since the zope schemas contain the relevant ui metadata, and the schema is the canonical definition of the rdb/sa schema. bonus is you get multidb support for the schema, as an example of doing things this way, https://svn.objectrealms.net/view/public/browser/ore.member/trunk/src/ore/m ember/example2.py the transmute funcction has the options of specifying base interfaes, so you also have the option at the risk of ordering dependencies of replacing the iface class thats a base arg to the transmute function with the result of the transmute function, presumably though if this being done in the same module (interfaces.py) then its not an issue though. Interesting approach, however, I doubt this is going to work when one has to access an existing relational database - like in my case. After all one has once again redundant definitions. Therefore in cases where the database is designed together with the Zope3 application, the transmute function could be an interesting approach, but in cases where the DDL-statements already exist, the generation of schemas out of the table definitions seem to be the better way. Moreover I'm also curious if advanced table definitions such as constraints, checks and the like can be generated from Zope schemas. ore.alchemist supports both notions, as both options are wanted for different use cases, ie both database as canonical schema representation and interfaces as canonical with automatic generation of the other form. it does support basic constraint inferment and generation from either canonical source. the solution above was presented here in the context of a particular deployment. cheers, kapil ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
Re: [Zope3-Users] Can interfaces be mutated cleanly?
On Fri, 13 Apr 2007 15:13:58 -0400, Hermann Himmelbauer [EMAIL PROTECTED] wrote: Am Freitag, 13. April 2007 20:33 schrieb Kapil Thangavelu: On Fri, 13 Apr 2007 02:36:07 -0400, Hermann Himmelbauer [EMAIL PROTECTED] wrote: Am Donnerstag, 12. April 2007 17:22 schrieb Christian Theune: Hi, I didn't find anything in the documentation or google on this: I want to define an interface like: class IMySchema(zope.interface.Interface): pass Later, I want to use ore.alchemist which currently is able to take a SQLAlchemy table description and turn it into a new interface/schema. Interesting - is ore.alchemist the package developed by Kapil Thangalevu? If yes, is it working? I had the impression that the project is abandoned. it is, and its working, its been in production since inception, has a number of features not present in the other sa zope integrations (schema generation, both from sa and from zope.schema, as well keyreference support, etc). unfortunately suffers a bit in that the formlib integration is currently targetting zope2/plone, but thats contained in a separate z2 product, as well as my own lack of time to promote it or work on new feature developmen at the moment. Formlib integration is still something I'm struggling with. I'm currently setting up forms (filling with data) manually via SetUpWidgets. Hopefully I will be able to break this down on a common denominator, refactor it and provide some ORMFormlib library which inherits from form.Form, we'll see... there are lots of rabbit holes here i found, esp. as regards object widget usage for embedded relations. i got the feeling that i was one of the few people using it.. it doesn't have a display mode, and always seeks to create a new object instead of updating in place were the primary issues. the rest of the widgets work fairly well out of the box. -kapil ___ Zope3-users mailing list [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope3-users
