Creators

By default, pulling values from the config object will instantiate components including modifiers. However, you can easily customize how exactly any values are processed by creating custom creators.

Creators must be registered just like components and modifiers. Then if you want certain components to always use such a custom creator, then you can include that creator name when registering the component.

import omnifig as fig

@fig.creator('custom-creator')
class SpecialCreator(fig.Node.DefaultCreator):
    def create_product(self, config, args, kwargs, silent=None):
        # do something special
        print('creating something special')
        return super().create_product(config, args, kwargs, silent=None)

@fig.component('some-component', creator='custom-creator')
class Something(fig.Configurable):
    def __init__(self, x=1):
        self.x = x

# then in a REPL:

>>> cfg = fig.create_config(_type='some-component', x=2)

>>> assert cfg.pull('x') == 2
creating something special

>>> obj = cfg.pull()
creating something special
>>> assert obj.x == 2
>>> assert isinstance(obj, Something)

Alternatively, you can specify the creator that should be used directly in the config under the key _creator.

>>> cfg = fig.create_config(_type='some-component', x=2, _creator='custom-creator')

>>> assert cfg.pull('x') == 2
creating something special
>>> assert obj.x == 2
>>> assert isinstance(obj, Something)

Lastly, you can specify the creator as a setting of the config object.

@fig.component('another-component') # without specifying a creator
class Simple(fig.Configurable):
    def __init__(self, y=1):
        self.y = y

# then in a REPL:

>>> cfg = fig.create_config(_type='another-component', y=5)

>>> obj1 = cfg.create() # uses default creator
>>> assert obj1.y == 5
>>> assert isinstance(obj1, Simple)

>>> with cfg.context(creator='custom-creator'):
...     obj2 = cfg.create() # now uses the custom creator
creating something special
>>> assert obj2.y == 5
>>> assert isinstance(obj2, Simple)

>>> obj3 = cfg.create() # outside of the context, using default creator
>>> assert obj3.y == 5
>>> assert isinstance(obj3, Simple)

>>> cfg.settings['creator'] = 'custom-creator'

>>> obj4 = cfg.create() # now back to custom-creator
creating something special
>>> assert obj4.y == 5
>>> assert isinstance(obj4, Simple)