Files
pydase/src/pydase/components/device_connection.py
2024-04-03 10:47:46 +02:00

78 lines
3.1 KiB
Python

import asyncio
import pydase.data_service
class DeviceConnection(pydase.data_service.DataService):
"""
Base class for device connection management within the pydase framework.
This class serves as the foundation for subclasses that manage connections to
specific devices. It implements automatic reconnection logic that periodically
checks the device's availability and attempts to reconnect if the connection is
lost. The frequency of these checks is controlled by the `_reconnection_wait_time`
attribute.
Subclassing
-----------
Users should primarily override the `connect` method to establish a connection
to the device. This method should update the `self._connected` attribute to reflect
the connection status:
>>> class MyDeviceConnection(DeviceConnection):
... def connect(self) -> None:
... # Implementation to connect to the device
... # Update self._connected to `True` if connection is successful,
... # `False` otherwise
... ...
Optionally, if additional logic is needed to determine the connection status,
the `connected` property can also be overridden:
>>> class MyDeviceConnection(DeviceConnection):
... @property
... def connected(self) -> bool:
... # Custom logic to determine connection status
... return some_custom_condition
...
Frontend Representation
-----------------------
In the frontend, this class is represented without directly exposing the `connect`
method and `connected` attribute. Instead, user-defined attributes, methods, and
properties are displayed. When `self.connected` is `False`, the frontend component
shows an overlay that allows manual triggering of the `connect()` method. This
overlay disappears once the connection is successfully re-established.
"""
def __init__(self) -> None:
super().__init__()
self._connected = False
self._autostart_tasks["_handle_connection"] = () # type: ignore
self._reconnection_wait_time = 10.0
def connect(self) -> None:
"""Tries connecting to the device and changes `self._connected` status
accordingly. This method is called every `self._reconnection_wait_time` seconds
when `self.connected` is False. Users should override this method to implement
device-specific connection logic.
"""
@property
def connected(self) -> bool:
"""Indicates if the device is currently connected or was recently connected.
Users may override this property to incorporate custom logic for determining
the connection status.
"""
return self._connected
async def _handle_connection(self) -> None:
"""Automatically tries reconnecting to the device if it is not connected.
This method leverages the `connect` method and the `connected` property to
manage the connection status.
"""
while True:
if not self.connected:
self.connect()
await asyncio.sleep(self._reconnection_wait_time)