README.md

Server instance

This module is a server-side module based on Flask and mqtt protocols that supports app and device access and management.

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The functions of the module include:

1. Support the addition of equipment
2. Support remote sending of switch lock (light switch) commands
3. Save and restore server-side state
4. Realize remote dynamic add code

Among them, 3 and 4 are not enabled, only the function is realized.

Module structure

This module contains two parts: mqtt_client.py and server2.py. The former is based on mqtt with some extensions to facilitate subsequent development, and the latter is a simple server-side example.

mqtt_client

Contains a device_interface class based on paho.mqttm.client.Client implementation. The main functions are as follows.

Add action

The action is essentially a function in python. When a subscribed message is received, the module will use the first word of the payload of the message as the key to look up the action table. If a corresponding function is found, then it will try to call this function. The requirement is to receive no more than 2 parameters, while specifying that the first parameter is the msg message in paho.mqtt, the second parameter is the class itself, and the return value is agreed if there is no return value, then nothing Execute, otherwise, convert the return value to string type, and then send the message based on the first word as the topic.

The function for adding actions is as follows:

def __check_func_can_be_add(self,action):
    if not (action and callable(action)):
        return -1
    action_def_path = action.__code__.co_filename
    action_def_relpath = os.path.relpath(action_def_path)
    if action_def_relpath[:2] is "..":
        return -1
    if action.__code__.co_argcount> 2:
        return -1
    return 0

def add_action(self,action,action_name=None):
    if self.__check_func_can_be_add(action) != 0:
        return -1
    action_func_name = action.__name__
    action_name = action_name if action_name else action_func_name
    action_def_path = action.__code__.co_filename
    self.action_load[action_func_name] = action_def_path
    self.action[action_name] = action
    self.action_func_name[action_func_name] = action_name
    return 0

The function of __check_func_can_be_add is to detect whether the passed-in parameter is callable, and to avoid interface abuse, so detect whether the file to which the passed-in object belongs is under the current project.

add_action is the interface function for adding actions, action must be

State recovery and preservation

Since it is a simple project, the state restoration and saving are stored in json files, and the topic of the device is not stored in the database. The corresponding state saving interface is save_to_config, and the state restoration interface is load_from_config, Save and read from ./congif.json by default.

Remote add code and dynamic import

The remote writing of the code here is realized by using mqtt to transfer py files, and it can be completed by adding _save_input_py_file in mqtt_client.py to the action list.

The dynamic import is to add the _load_python_file in mqtt_client.py to the action list, and then you can have this function.

Singleton mode support

To open singleton mode, you need to set the ON_SINGLE_PATTERN in mqtt_client.py to True, and then the device_interface created in all threads will be the same.

server2

The implementation in server2.py is based on device_interface and flask in mqtt_client.

The mqtt interface of the server is:

1. lock: The interface for locking, the implementation here is to send a lock command to all devices
2. unlock: The interface for unlocking the lock, the implementation here is to send a lock command to all devices
3. find_stranger: An interface for finding strangers. This interface executes instructions to send strangers discovered to the corresponding topic, and gives links to pictures of strangers
4. hand_shake: Handshake interface, used for device access

Flask implements the following interfaces:

1. /hello: Used to test whether the server is started correctly
2. /lock: Same as mqtt's lock
3. /unlock: Same as mqtt's unlock
4. /test: The interface for unlocking and closing the lock, unlocking or closing the lock according to the upload message
5. /get_pic: Used to download images of strangers