doit task creation

On my previous post I explained one way to create tasks for doit in a higher level than the default plain python dictionaries.

I just pushed a change that will allow the creation of not only decorators to generate tasks but also classes and instance objects.

The idea is very simple. Apart from collect functions that start with the name task_. The doit loader will now also execute the create_doit_task callable from any object that contains this attribute.

Note you will need the developement version of doit to run this code.

decorator example

##########################################################
## the decorator

def task(*args, **meta):
    def decorated(func):
        def create():
            task_dict = {'basename': func.__name__, 'actions': [func]}
            task_dict.update(meta)
            return task_dict
        func.create_doit_tasks = create
        return func

    if args:
        # decorator without parameters
        return decorated(args[0])
    else:
        return decorated


###########################################################
## task definition

DOIT_CONFIG = {'verbosity': 2}


@task
def simple():
    print "ho"

@task(file_dep=['dodo.py'])
def hello():
    print "hi"

class example

This interface was suggested by Thomas here.

class Task(object):
    @classmethod
    def create_doit_tasks(cls):
        if cls is Task:
            return # avoid create tasks from base class 'Task'
        instance = cls()
        kw = dict((a, getattr(instance, a)) for a in dir(instance) if not a.startswith('_'))
        kw.pop('create_doit_tasks')
        if 'actions' not in kw:
            kw['actions'] = [kw.pop('run')]
        if 'doc' not in kw:
            kw['doc'] = cls.__doc__
        return kw



class hello(Task):
    """Hello from Python."""
    targets = ['hello.txt']

    def run(self):
        with open(self.targets[0], "a") as output:
            output.write("Hello world.")

class checker(Task):
    """Run pyflakes."""
    actions = ['pyflakes sample.py']
    file_dep = ['sample.py']

Object example

class TaskHello(object):
    REG = [] # save instances

    def __init__(self, name):
        self.name = name
        self.REG.append(self)

    def say_hello(self):
        print "hello", self.name

    @classmethod
    def create_doit_tasks(cls):
        for inst in cls.REG:
            yield {
                'basename': inst.name,
                'actions': [inst.say_hello],
                }

######################

DOIT_CONFIG = {'verbosity': 2}

for name in ('foo', 'bar', 'spam'):
    TaskHello(name)