About

The Workflow library provides a method of running Finite State Machines with memory. It can be used to execute a set of methods, complete with conditions and patterns.

Workflow allows for a number of independent pieces of data to be processed by the same logic, while allowing for the entire process to be forwarded, backwarded, paused, inspected, re-executed, modified and stored.

Basic workflow usage



In [1]:

    
from workflow.engine import GenericWorkflowEngine

Instantiate a workflow engine



In [2]:

    
my_engine = GenericWorkflowEngine()

Create tasks



In [3]:

    
from functools import wraps

def print_data(obj, eng):
    """Print the data found in the token."""
    print(obj.data)
    
def add_data(number_to_add):
    """Add number_to_add to obj.data."""
    @wraps(add_data)
    def _add_data(obj, eng):
        obj.data += number_to_add
    return _add_data

Create a workflow definition



In [4]:

    
my_workflow_definition = [
    add_data(1),
    print_data
]

Define tokens



In [5]:

    
class MyObject:
    def __init__(self, data):
        self._data = data
    
    @property
    def data(self):
        return self._data
    
    @data.setter
    def data(self, value):
        print(self)
        self._data = value
    
    def __repr__(self):
        return "{0} : {1}".format(hex(id(self)), self._data)

my_object0 = MyObject(0)
my_object1 = MyObject(1)

Run the engine



In [6]:

    
my_engine.callbacks.replace(my_workflow_definition)



In [7]:

    
my_engine.process([my_object0, my_object1])









    



0x7f1ff00d2b70 : 0
1
0x7f1ff00d2c88 : 1
2

Resuing the engine



In [8]:

    
my_engine.process([my_object0, my_object1])









    



0x7f1ff00d2b70 : 1
2
0x7f1ff00d2c88 : 2
3

Loops and Interrupts

TODO:

http://workflow.readthedocs.io/en/latest/#loops-and-interrupts