Hi Charlie, |--==> On Thu, 29 Jul 2010 10:45:58 +0200, "Charlie Clark" <charlie.cl...@clark-consulting.eu> said:
CC> Am 29.07.2010, 10:25 Uhr, schrieb Free Ekanayaka CC> <free.ekanay...@gmail.com>: >>I agree that model objects and forms are not generally tight together, >>even though I'd argue that virtually every web application will need >>basic CRUD for the core entities. CC> Form inference via schema adapter should be possible but I think there is CC> consensus that interfaces that are schemas can cause more problems than CC> they solve. Convenience versus overhead and confusion. Agreed, I'm not thrilled by it either. TH> I use a UML modeling tool to generate all my models and form >>schemas so I TH> tend not to write much code in these entities. >>That's interesting, any pointer/link for this specific tool? TH> I personally think the form schema is much more about the view than >>the TH> model. >>Sure, however I believe the issue I was raising is orthogonal to this >>one. Regardless how tight or loosely the form schema is bound to the >>model, the authorization for a view in Repoze.bfg can effectively be >>only True or False, which is simple and nice, but sometimes doesn't fit >>what you need to do. CC> In those cases you are free to add more to it such as, as Chris said, CC> security proxies. Making this standard adds a lot of overhead to cases CC> where it is totally irrelevant. Absolutely. My question was more "is there another way I can think to the problem, that plays well with plain Repoze.bfg (whose design I like a lot, btw)?". I also appreciate the fact that, like Zope, Repoze.bfg is pretty pluggable, so you can add what you need. CC> NB. BFG's openness with regard to storage means you have to think about CC> non-ZODB environments if you wish to have object-level security. >>Let's make an example. You have a web application for sharing drawings, >>you can upload drawings and for each drawing decide which other users >>you want to share that drawing with. If you share a drawing with another >>person, that other person can perform the same operations as you on it, >>like tagging it or removing it. >>Now let's say that you have views that act on collections of drawings, >>like you could have a view for handling an HTTP request for tagging a >>certain group of drawings or deleting them. The HTTP request for those >>views would typically have a parameter holding a list for drawing IDs to >>act on. How do you define the permission on those views? With a >>model-based permissions system, you would simply make the view public >>and let the model raise Unauthorized if you attempt to do something on a >>drawing you don't have access too. However with a view-based permission >>system you need to use some other pattern, and I'm not sure what would >>be best. CC> I would think you would need to add something to your application to CC> handle this (something akin to workflow) but I don't see why you can't CC> stick with security. BFG provides all the necessary hooks for fine-grained CC> security. Introducing something like a workflow might be a good idea, I'll think more about it, thanks. CC> Regarding Maartijn's discussion of configuration close to the objects. CC> Having grown up with Zope 2 I'm not keen to see declareProtected(), etc. CC> return for this even if you have decorators. Much better, in my view, to CC> have adapters and views implement behaviour and secure these. CC> I guess the only thing that's missing is security aware form generation, CC> ie. the ability to lock down parts of the form. With a form generation CC> library such as deform this can be done at the view level, although it's CC> not ideal. Yeah, and you need security-awareness both ways, when you display the form and when you process it. Cheers, Free _______________________________________________ Repoze-dev mailing list Repoze-dev@lists.repoze.org http://lists.repoze.org/listinfo/repoze-dev
