minecraft-bot/custom/managers/chat.py

import json

from minecraft.networking.packets import clientbound, serverbound

class ChatManager:
    def __init__(self, global_state):
        self.g = global_state
        self.handler = None

        self.g.connection.register_packet_listener(self.print_chat, clientbound.play.ChatMessagePacket)

    def translate_chat(self, data):
        if isinstance(data, str):
            return data
        elif 'extra' in data:
            return ''.join([self.translate_chat(x) for x in data['extra']])
        elif 'text' in data:
            return data['text']
        else:
            return '?'

    def print_chat(self, chat_packet):
        # TODO: Replace with handler
        try:
            source = chat_packet.field_string('position')
            text = self.translate_chat(json.loads(chat_packet.json_data))
            print('[%s] %s'%(source, text))
            if self.handler:
                self.handler((source, text))
        except Exception as ex:
            print('Exception %r on message (%s): %s' % (ex, chat_packet.field_string('position'), chat_packet.json_data))

    def set_handler(self, func):
        self.handler = func

    def send(self, text):
        if not text:
            # Prevents connection bug when sending empty chat message
            return
        packet = serverbound.play.ChatPacket()
        packet.message = text
        self.g.connection.write_packet(packet)