Re: "inversion of control" in Python - look at: http://plope.com/control_inversion http://code.activestate.com/recipes/413268-dependency-injection-the-python-way/ http://blog.code.zaubersoftware.com/2009/04/controlfreak-python-inversion-of.html
On Jan 5, 12:06 am, Ondřej Mirtes <ond...@mirtes.cz> wrote: > Hello, > I am experienced PHP developer (and by PHP I mean advanced programming > with MVC frameworks, TDD, ORM libraries, design patterns and such, so > no scoffing please :)) and I would like to try something new. I've > chosen Python and Django and I am building my bachelor thesis project > with it. > > I dived directly into django-nonrel fork, because I am building the > project on App Engine. However, I have few basic questions that > concern basic relational Django as well. > > 1) Since Python has no object encapsulation, I have no idea how to > implement computed columns in its models. E. g. I want to save forum > post rating in the "posts" table even if I have related table with all > the related post votes because it's faster and no joins are required > to get the rating value. > > 2) I would like to perform some integrity checking before saving > object to the database. I found here (http://docs.djangoproject.com/en/ > 1.2/topics/db/models/#overriding-predefined-model-methods) that I can > override entity save method and stop it's execution before calling > parent implementation. However, this didn't work for me for two > reasons - it somehow caused 500 error on App Engine (because the app > does not know that the object was not saved?) and it does not meet my > needs - I would like to "attach" some error message to this > application state and I would like this message to bubble up to the > form errors (in case it happens when a form is submitted) in a way > compatible with Django admin, so the user can fix the problem. > > 3) I would like to read about some best practices about midsize and > large Django projects. How to organize the code, what directory > structure to choose etc. Are there any additional layers between model > and views widely used? Where should I put my code that is not directly > related to model and is used in more than one view? Can you recommend > me some articles about this topic? > > 4) What about dependency injection? From what I saw so far it seems > like Django is full of singletons, static attributes and methods and > hidden dependencies, which are considered as bad practice. For example > how can I use two connections to two different databases to load and > save model entities? Are there any "inversion of control" concepts? > > Thank you very much! And you can expect more questions to come in this > thread :) > > Ondřej Mirtes from Prague, Czech Republic -- You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-us...@googlegroups.com. To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/django-users?hl=en.
