Source code for apache_beam.coders.observable

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"""Observable base class for iterables.

For internal use only; no backwards-compatibility guarantees.
"""


[docs]class ObservableMixin(object): """For internal use only; no backwards-compatibility guarantees. An observable iterable. Subclasses need to call self.notify_observers with any object yielded. """ def __init__(self): self.observers = []
[docs] def register_observer(self, callback): self.observers.append(callback)
[docs] def notify_observers(self, value, **kwargs): # self.observers is almost always empty if self.observers: for o in self.observers: o(value, **kwargs)