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BlackboardHistory

dendron.decorators.blackboard_history.BlackboardHistory

Bases: DecoratorNode

The Blackboard history node keeps track of a blackboard entry related to a child node. Every time this node is ticked, it examines the blackboard and records the value stored at the child_key before tick()ing the child.

The history is itself stored in the blackboard, by default at the key "{child_node.name}/{child_key}/history".

Parameters:

Name Type Description Default
name `str`

The given name of this node.

 required
child `dendron.tree_node.TreeNode`

The child node whose blackboard history we want to track.

 required
child_key `str`

The blackboard key we want to record values for.

 'in'
Source code in src/dendron/decorators/blackboard_history.py 
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class BlackboardHistory(DecoratorNode):
    """
    The Blackboard history node keeps track of a blackboard entry 
    related to a child node. Every time this node is ticked, it 
    examines the blackboard and records the value stored at the
    `child_key` before `tick()`ing the child.

    The history is itself stored in the blackboard, by default at
    the key "{child_node.name}/{child_key}/history".

    Args:
        name (`str`):
            The given name of this node.
        child (`dendron.tree_node.TreeNode`):
            The child node whose blackboard history we want to track.
        child_key (`str`):
            The blackboard key we want to record values for.
    """
    def __init__(self, name, child: TreeNode, child_key : str = "in") -> None:
        super().__init__(name, child)

        self.child_key = self.child_node.input_key
        self.history_key = f"{self.child_node.name}/{child_key}/history"
        if self.blackboard is not None:
            self.blackboard[self.history_key] = []

    def set_blackboard(self, bb : Blackboard) -> None:
        """
        Assign a new blackboard for history tracking.

        Args:
            bb (`dendron.blackboard.Blackboard`):
                The new blackboard to track.
        """
        self.blackboard = bb
        self.blackboard[self.history_key] = []

        self.child_node.set_blackboard(bb)

    def reset(self) -> None:
        """
        Clear the history and instruct the child to reset.
        """
        self.blackboard[self.history_key] = []
        self.child_node.reset()

    def tick(self) -> NodeStatus:
        """
        Record the value stored in the blackboard at `child_key` and
        then instruct the child node to execute its `tick()` function.
        """
        latest = self.blackboard[self.child_key]
        self.blackboard[self.history_key].append(latest)

        status = self.child_node.execute_tick()

        return status

reset()

Clear the history and instruct the child to reset.

Source code in src/dendron/decorators/blackboard_history.py 
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def reset(self) -> None:
    """
    Clear the history and instruct the child to reset.
    """
    self.blackboard[self.history_key] = []
    self.child_node.reset()

set_blackboard(bb)

Assign a new blackboard for history tracking.

Parameters:

Name Type Description Default
bb `dendron.blackboard.Blackboard`

The new blackboard to track.

 required
Source code in src/dendron/decorators/blackboard_history.py 
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def set_blackboard(self, bb : Blackboard) -> None:
    """
    Assign a new blackboard for history tracking.

    Args:
        bb (`dendron.blackboard.Blackboard`):
            The new blackboard to track.
    """
    self.blackboard = bb
    self.blackboard[self.history_key] = []

    self.child_node.set_blackboard(bb)

tick()

Record the value stored in the blackboard at child_key and then instruct the child node to execute its tick() function.

Source code in src/dendron/decorators/blackboard_history.py 
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def tick(self) -> NodeStatus:
    """
    Record the value stored in the blackboard at `child_key` and
    then instruct the child node to execute its `tick()` function.
    """
    latest = self.blackboard[self.child_key]
    self.blackboard[self.history_key].append(latest)

    status = self.child_node.execute_tick()

    return status