|
1
|
|
|
""" |
|
2
|
|
|
server side implementation of callback event |
|
3
|
|
|
""" |
|
4
|
|
|
|
|
5
|
|
|
from collections import OrderedDict |
|
6
|
|
|
from enum import Enum |
|
7
|
|
|
import asyncio |
|
8
|
|
|
|
|
9
|
|
|
|
|
10
|
|
|
class CallbackType(Enum): |
|
11
|
|
|
""" |
|
12
|
|
|
The possible types of a Callback type. |
|
13
|
|
|
|
|
14
|
|
|
:ivar Null: |
|
15
|
|
|
:ivar MonitoredItem: |
|
16
|
|
|
|
|
17
|
|
|
""" |
|
18
|
|
|
Null = 0 |
|
19
|
|
|
ItemSubscriptionCreated = 1 |
|
20
|
|
|
ItemSubscriptionModified = 2 |
|
21
|
|
|
ItemSubscriptionDeleted = 3 |
|
22
|
|
|
WritePerformed = 4 |
|
23
|
|
|
|
|
24
|
|
|
|
|
25
|
|
|
class Callback(object): |
|
26
|
|
|
def __init__(self): |
|
27
|
|
|
self.__name = None |
|
28
|
|
|
|
|
29
|
|
|
def setName(self, name): |
|
30
|
|
|
self.__name = name |
|
31
|
|
|
|
|
32
|
|
|
def getName(self): |
|
33
|
|
|
return self.__name |
|
34
|
|
|
|
|
35
|
|
|
|
|
36
|
|
|
class ServerItemCallback(Callback): |
|
37
|
|
|
def __init__(self, request_params, response_params, user=None): |
|
38
|
|
|
self.request_params = request_params |
|
39
|
|
|
self.response_params = response_params |
|
40
|
|
|
self.user = user |
|
41
|
|
|
|
|
42
|
|
|
|
|
43
|
|
|
class CallbackSubscriberInterface(object): |
|
44
|
|
|
def getSubscribedEvents(self): |
|
45
|
|
|
raise NotImplementedError() |
|
46
|
|
|
|
|
47
|
|
|
|
|
48
|
|
|
class CallbackDispatcher(object): |
|
49
|
|
|
def __init__(self): |
|
50
|
|
|
self._listeners = {} |
|
51
|
|
|
|
|
52
|
|
|
async def dispatch(self, eventName, event=None): |
|
53
|
|
|
if event is None: |
|
54
|
|
|
event = Callback() |
|
55
|
|
|
elif not isinstance(event, Callback): |
|
56
|
|
|
raise ValueError('Unexpected event type given') |
|
57
|
|
|
event.setName(eventName) |
|
58
|
|
|
if eventName not in self._listeners: |
|
59
|
|
|
return event |
|
60
|
|
|
for listener in self._listeners[eventName].values(): |
|
61
|
|
|
if asyncio.iscoroutinefunction(listener): |
|
62
|
|
|
await listener(event, self) |
|
63
|
|
|
else: |
|
64
|
|
|
listener(event, self) |
|
65
|
|
|
|
|
66
|
|
|
return event |
|
67
|
|
|
|
|
68
|
|
|
def addListener(self, eventName, listener, priority=0): |
|
69
|
|
|
if eventName not in self._listeners: |
|
70
|
|
|
self._listeners[eventName] = {} |
|
71
|
|
|
self._listeners[eventName][priority] = listener |
|
72
|
|
|
self._listeners[eventName] = OrderedDict(sorted(self._listeners[eventName].items(), key=lambda item: item[0])) |
|
73
|
|
|
|
|
74
|
|
|
def removeListener(self, eventName, listener=None): |
|
75
|
|
|
if eventName not in self._listeners: |
|
76
|
|
|
return |
|
77
|
|
|
if not listener: |
|
78
|
|
|
del self._listeners[eventName] |
|
79
|
|
|
else: |
|
80
|
|
|
for p, l in self._listeners[eventName].items(): |
|
81
|
|
|
if l is listener: |
|
82
|
|
|
self._listeners[eventName].pop(p) |
|
83
|
|
|
return |
|
84
|
|
|
|
|
85
|
|
|
def addSubscriber(self, subscriber): |
|
86
|
|
|
if not isinstance(subscriber, CallbackSubscriberInterface): |
|
87
|
|
|
raise ValueError('Unexpected subscriber type given') |
|
88
|
|
|
for eventName, params in subscriber.getSubscribedEvents().items(): |
|
89
|
|
|
if isinstance(params, str): |
|
90
|
|
|
self.addListener(eventName, getattr(subscriber, params)) |
|
91
|
|
|
elif isinstance(params, list): |
|
92
|
|
|
if not params: |
|
93
|
|
|
raise ValueError(f'Invalid params "{repr(params)}" for event "{str(eventName)}"') |
|
94
|
|
|
if len(params) <= 2 and isinstance(params[0], str): |
|
95
|
|
|
priority = params[1] if len(params) > 1 else 0 |
|
96
|
|
|
self.addListener(eventName, getattr(subscriber, params[0]), priority) |
|
97
|
|
|
else: |
|
98
|
|
|
for listener in params: |
|
99
|
|
|
priority = listener[1] if len(listener) > 1 else 0 |
|
100
|
|
|
self.addListener(eventName, getattr(subscriber, listener[0]), priority) |
|
101
|
|
|
else: |
|
102
|
|
|
raise ValueError(f'Invalid params for event "{str(eventName)}"') |
|
103
|
|
|
|
FreeOpcUa /
opcua-asyncio
