48 lines
1.4 KiB
Python
48 lines
1.4 KiB
Python
from copy import deepcopy
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class Memento(object):
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"""
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Memento class as part of the Memento design pattern.
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- External Usage documentation: U{https://github.com/tylerlaberge/PyPatterns/wiki/Behavioral-Pattern-Usage}
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- External Memento Pattern documentation: U{https://en.wikipedia.org/wiki/Memento_pattern}
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"""
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def __init__(self, state):
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"""
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Initialize a new Memento instance.
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@param state: The state to save in this Memento.
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@type state: dict
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"""
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self.__state = state
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@property
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def state(self):
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return self.__state
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class Originator(object):
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"""
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Originator base class as part of the Memento design pattern.
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- External Usage documentation: U{https://github.com/tylerlaberge/PyPatterns/wiki/Behavioral-Pattern-Usage}
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- External Mediator Pattern documentation: U{https://en.wikipedia.org/wiki/Memento_pattern}
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"""
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def commit(self):
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"""
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Commit this objects state to a memento.
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@return: A memento instance with this objects state.
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"""
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return Memento(deepcopy(self.__dict__))
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def rollback(self, memento):
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"""
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Rollback this objects state to a previous state.
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@param memento: The memento object holding the state to rollback to.
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@type memento: Memento
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"""
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self.__dict__ = memento.state
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