Thanks for your additional comments, Mark - you've given me more stuff to think about! :) I appreciate you taking the time to explain more about this subject.
On Thu, Nov 6, 2008 at 2:57 PM, Mark Ramm <[EMAIL PROTECTED]>wrote: > > > I'll tell you the truth, the app-based design is a big deal to me, so > > much so that I'm strongly leaning towards moving to Django even though > > in most other ways I prefer TG. I really think that TG very strongly > > needs a clear, easy and well-documented way to plug in functionality > > in packages to existing projects. I feel that it's a sin for something > > that works so smoothly in using a PHP framework to be so hard to do in > > a Python framework unless you have an excellent reason not to build in > > the functionality. > > This is very easy to do now in TG2 and TG -- except for the datamodel. > And the django people haven't solved that problem particularly well > either. The thing is that you need to create join tables for things > like comments on posts and comments on pages and coments on messages, > etc. This "connective tissue" is the stuff that hooks these apps > together at the data layer, and it's the part that can't be in the > individual apps. > > While you can design apps the reduce the amount of "connective tissue" > that they have, and the Django people have pushed that model quite a > bit, it has some significant performance and flexibility drawbacks. > The other alternative is to put the connective tissue in by copying > the app in, and hacking up it's model a bit to fit it into your > system. This is also a method commonly used in the Django community. > But it makes it hard to maintain apps, across versions, since new > versions will have to be merged into your now modified code. > > Another solution is the one we started in TG2 which is to make as few > assumptions about the model as we can in the rest of the application > code, and then allow the user to configure their own model classes > which meet those assumptions and place them into a known location on > the config object. This takes extra work because we have to think > through what the minimum interface requiremnt for that app's model is, > and document it, but it's not hard to do. > > If you want to take a look at how this works in practice there's the > silverplate app which provides user management for TG2 applications > that use the standard tgext.authorization stuff. > > Another approach is to create a model factory that you can use to > create the model classes you need dynamically based on some > configuration information. This adds a little bit of complexity to > creating the reusable app, but makes things much more flexible. > > And to the extent that you're apps have separate data that does not > interact significantly, none of this is a problem at all, and all you > need to do is make a module and put a app_root controller in there > that you can import and instantiate in your root controller. ;) > > --Mark Ramm > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "TurboGears" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/turbogears?hl=en -~----------~----~----~----~------~----~------~--~---
