Administrative setup

First you should define one or more ProgramInterface objects via django admin interface (http://localhost:8000/admin/business_logic/programinterface/).

Each ProgramInterface must contain one or more ProgramArgument objects. The ProgramArgument object represents one instance of django.db.Model derived class specified as django.contrib.contentypes.ContentType instance (e.g. for your custom Order model) and his keyword argumet name (e.g. order).

Each ProgramArgument object must contain one or more ProgramArgumentField which represents one field of django model (e.g. sum for Order object or for city field nested into Order DeliveryAddress model).

If you want to use system-wide references (e.g. your custom City or ProductCategory django model) and you define represented ProgramArgumentField you should register referenced model via django admin interface(http://localhost:8000/admin/business_logic/referencedescriptor/).

Next create one or more Program objects which must implements described ProgramInterface(e.g. named “On Order create” with “on_order_create” code field for programmatic access)

Invocation injecting

You may inject execution engine call at arbitrary place of your code, such as custom, model.post_save() methods, any django.dispatch.Signal handler or so on. Just instantiate appropriate ProgramVersion object and pass kwargs described in the ProgramInterface admin page to its execute() method. E.g.:

from django.views.generic.edit import CreateView

from business_logic.models import Program

class OrderCreate(CreateView):
    def form_valid(self, form):
       order =
       program = Program.objects.get(code="on_order_create")
       program_version = program.versions.order_by("id").last()

The business_logic.models.ProgramVersion.execute() method can accept instance of business_logic.models.Context object. If this parameter omitted execute() method creates new instance of business_logic.models.Context with specified by business_logic.models.ExecutionEnvironment parameters or with default parameters.

It can be initialized by the following parameters:

The ProgramVersion.execute() method returns the Context instance.