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.
