#!/usr/bin/env python
#
# License: BSD
# https://raw.githubusercontent.com/stonier/py_trees/devel/LICENSE
#
##############################################################################
# Documentation
##############################################################################
"""
.. argparse::
:module: py_trees.demos.stewardship
:func: command_line_argument_parser
:prog: py-trees-demo-tree-stewardship
.. graphviz:: dot/stewardship.dot
.. image:: images/tree_stewardship.gif
"""
##############################################################################
# Imports
##############################################################################
import argparse
import functools
import json
import py_trees
import sys
import time
import py_trees.console as console
##############################################################################
# Classes
##############################################################################
def description(root):
content = "A demonstration of logging with trees.\n\n"
content += "This demo utilises a WindsOfChange visitor to trigger\n"
content += "a post-tick handler to dump a serialisation of the\n"
content += "tree to a json log file.\n"
content += "\n"
content += "This coupling of visitor and post-tick handler can be\n"
content += "used for any kind of event handling - the visitor is the\n"
content += "trigger and the post-tick handler the action. Aside from\n"
content += "logging, the most common use case is to serialise the tree\n"
content += "for messaging to a graphical, runtime monitor.\n"
content += "\n"
if py_trees.console.has_colours:
banner_line = console.green + "*" * 79 + "\n" + console.reset
s = "\n"
s += banner_line
s += console.bold_white + "Logging".center(79) + "\n" + console.reset
s += banner_line
s += "\n"
s += content
s += "\n"
s += banner_line
else:
s = content
return s
def epilog():
if py_trees.console.has_colours:
return console.cyan + "And his noodly appendage reached forth to tickle the blessed...\n" + console.reset
else:
return None
def command_line_argument_parser():
parser = argparse.ArgumentParser(description=description(create_tree()),
epilog=epilog(),
formatter_class=argparse.RawDescriptionHelpFormatter,
)
group = parser.add_mutually_exclusive_group()
group.add_argument('-r', '--render', action='store_true', help='render dot tree to file')
group.add_argument('-i', '--interactive', action='store_true', help='pause and wait for keypress at each tick')
return parser
[docs]def logger(winds_of_change_visitor, behaviour_tree):
"""
A post-tick handler that logs the tree (relevant parts thereof) to a yaml file.
"""
if winds_of_change_visitor.changed:
print(console.cyan + "Logging.......................yes\n" + console.reset)
tree_serialisation = {
'tick': behaviour_tree.count,
'nodes': []
}
for node in behaviour_tree.root.iterate():
node_type_str = "Behaviour"
for behaviour_type in [py_trees.composites.Sequence,
py_trees.composites.Selector,
py_trees.composites.Parallel,
py_trees.decorators.Decorator]:
if isinstance(node, behaviour_type):
node_type_str = behaviour_type.__name__
node_snapshot = {
'name': node.name,
'id': str(node.id),
'parent_id': str(node.parent.id) if node.parent else "none",
'child_ids': [str(child.id) for child in node.children],
'tip_id': str(node.tip().id) if node.tip() else 'none',
'class_name': str(node.__module__) + '.' + str(type(node).__name__),
'type': node_type_str,
'status': node.status.value,
'message': node.feedback_message,
'is_active': True if node.id in winds_of_change_visitor.ticked_nodes else False
}
tree_serialisation['nodes'].append(node_snapshot)
if behaviour_tree.count == 0:
with open('dump.json', 'w+') as outfile:
json.dump(tree_serialisation, outfile, indent=4)
else:
with open('dump.json', 'a') as outfile:
json.dump(tree_serialisation, outfile, indent=4)
else:
print(console.yellow + "Logging.......................no\n" + console.reset)
[docs]def display_ascii_tree(snapshot_visitor, behaviour_tree):
"""
Prints an ascii tree with the current snapshot status.
"""
print("\n" + py_trees.display.ascii_tree(
behaviour_tree.root,
snapshot_information=snapshot_visitor)
)
def create_tree():
every_n_success = py_trees.behaviours.SuccessEveryN("EveryN", 5)
sequence = py_trees.composites.Sequence(name="Sequence")
guard = py_trees.behaviours.Success("Guard")
periodic_success = py_trees.behaviours.Periodic("Periodic", 3)
finisher = py_trees.behaviours.Success("Finisher")
sequence.add_child(guard)
sequence.add_child(periodic_success)
sequence.add_child(finisher)
sequence.blackbox_level = py_trees.common.BlackBoxLevel.COMPONENT
idle = py_trees.behaviours.Success("Idle")
root = py_trees.composites.Selector(name="Logging")
root.add_child(every_n_success)
root.add_child(sequence)
root.add_child(idle)
return root
##############################################################################
# Main
##############################################################################
[docs]def main():
"""
Entry point for the demo script.
"""
args = command_line_argument_parser().parse_args()
py_trees.logging.level = py_trees.logging.Level.DEBUG
tree = create_tree()
print(description(tree))
####################
# Rendering
####################
if args.render:
py_trees.display.render_dot_tree(tree)
sys.exit()
####################
# Tree Stewardship
####################
behaviour_tree = py_trees.trees.BehaviourTree(tree)
debug_visitor = py_trees.visitors.DebugVisitor()
snapshot_visitor = py_trees.visitors.SnapshotVisitor()
winds_of_change_visitor = py_trees.visitors.WindsOfChangeVisitor()
behaviour_tree.visitors.append(debug_visitor)
behaviour_tree.visitors.append(snapshot_visitor)
behaviour_tree.visitors.append(winds_of_change_visitor)
behaviour_tree.add_post_tick_handler(functools.partial(display_ascii_tree, snapshot_visitor))
behaviour_tree.add_post_tick_handler(functools.partial(logger, winds_of_change_visitor))
behaviour_tree.setup(timeout=15)
####################
# Tick Tock
####################
if args.interactive:
py_trees.console.read_single_keypress()
while True:
try:
behaviour_tree.tick()
if args.interactive:
py_trees.console.read_single_keypress()
else:
time.sleep(0.5)
except KeyboardInterrupt:
break
print("\n")