Description

The purpose of this app is to allow adding dynamic conditions to relations between objects. How is this useful? ------------------- Let's say you develop an application that will present content to user based on various conditions. Gamification comes to mind. Let's say you want to set the conditions on a per-user or per-group basis. For example girls get happy hours on Saturday and boys get them on Thursdays. Hardcoding that would be a bit harsh if you tend to change your mind frequently. Requirements ------------ Django >= 1.4 Usage ----- After installing the package and adding 'clausula' to INSTALLED_APPS you should define some abstract conditions you'd like to use. Do this by creating a file `conditions.py` in your app. Then you need to import `clauses` registry, define your conditions and register them. Example `conditions.py`:: def day_of_week_clause(obj, *args, **kwargs): import datetime weekday = datetime.date.today().weekday() if weekday == int(obj.param): return True return False clauses.register(day_of_week_clause, "checks day of week") Each condition is a function that fullows these rules: * it takes one mandatory argument: an `object` (a :class:`Condition` instance) * it silently accepts any number of optional arguments (*args, **kwargs) * it returns a boolean value `clauses.register` accepts two arguments: a callable and a string representation that will be displayed in Admin. The `object` is guaranteed to have a `param` attribute which holds a string which can be used to compute returned boolean value. There can also be some relations available as :class:`Condition` is a subclass of :class:`django.db.models.Model`. Feel free to experiment and find some hackish uses for this package.