Completed
Pull Request — master (#161)
by Denis
03:18
created

EventGenerator.__init__()   F

Complexity

Conditions 10

Size

Total Lines 37

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 23
CRAP Score 10.5696

Importance

Changes 1
Bugs 0 Features 0
Metric Value
cc 10
c 1
b 0
f 0
dl 0
loc 37
ccs 23
cts 28
cp 0.8214
crap 10.5696
rs 3.1304

How to fix   Complexity   

Complexity

Complex classes like EventGenerator.__init__() often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.

Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.

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import logging
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from datetime import datetime
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from opcua import ua
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from opcua import Node
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import uuid
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class EventGenerator(object):
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    """
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    Create an event based on an event type. Per default is BaseEventType used.
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    Object members are dynamically created from the base event type and send to
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    client when evebt is triggered (see example code in source)
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    Arguments to constructor are:
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        server: The InternalSession object to use for query and event triggering
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        source: The emiting source for the node, either an objectId, NodeId or a Node
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        etype: The event type, either an objectId, a NodeId or a Node object
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    """
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    def __init__(self, isession, etype=None, source=ua.ObjectIds.Server):
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        if not etype:
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            etype = ua.BaseEvent()
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        self.logger = logging.getLogger(__name__)
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        self.isession = isession
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        self.event = None
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        node = None
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        if isinstance(etype, ua.BaseEvent):
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            self.event = etype
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        elif isinstance(etype, Node):
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            node = etype
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        elif isinstance(etype, ua.NodeId):
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            node = Node(self.isession, etype)
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        else:
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            node = Node(self.isession, ua.NodeId(etype))
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        if node:
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            self.event = get_event_from_node(node)
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        if isinstance(source, Node):
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            pass
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        elif isinstance(source, ua.NodeId):
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            source = Node(isession, source)
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        else:
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            source = Node(isession, ua.NodeId(source))
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        if self.event.SourceNode:
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            if source.nodeid != self.event.SourceNode:
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                self.logger.warning("Source NodeId: '%s' and event SourceNode: '%s' are not the same. Using '%s' as SourceNode", str(source.nodeid), str(self.event.SourceNode), str(self.event.SourceNode))
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                source = Node(self.isession, self.event.SourceNode)
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        self.event.SourceNode = source.nodeid
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        self.event.SourceName = source.get_display_name().Text
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        source.set_attribute(ua.AttributeIds.EventNotifier, ua.DataValue(ua.Variant(1, ua.VariantType.Byte)))
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    def __str__(self):
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        return "EventGenerator(Type:{}, Source:{}, Time:{}, Message: {})".format(self.EventType, self.SourceNode, self.Time, self.Message)
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    __repr__ = __str__
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    def trigger(self, time=None, message=None):
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        """
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        Trigger the event. This will send a notification to all subscribed clients
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        """
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        self.event.EventId = ua.Variant(uuid.uuid4().hex, ua.VariantType.ByteString)
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        if time:
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            self.event.Time = time
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        else:
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            self.event.Time = datetime.utcnow()
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        self.event.RecieveTime = datetime.utcnow()
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        #FIXME: LocalTime is wrong but currently know better. For description s. Part 5 page 18
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        self.event.LocalTime = datetime.utcnow()
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        if message:
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            self.Message = ua.LocalizedText(message)
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        elif not self.event.Message:
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            self.event.Message = ua.LocalizedText(self.source.get_browse_name().Text)
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        self.isession.subscription_service.trigger_event(self.event)
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def get_event_from_node(node):
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    if node.nodeid.Identifier in ua.uaevents_auto.IMPLEMNTED_EVENTS.keys():
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        return ua.uaevents_auto.IMPLEMNTED_EVENTS[node.nodeid.Identifier]()
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    else:
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        parent_identifier, parent_eventtype = _find_parent_eventtype(node)
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        if not parent_eventtype:
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            return None
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        class CustomEvent(parent_eventtype):
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            def __init__(self):
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                super(CustomEvent, self).__init__(extended=True)
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                curr_node = node
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                while curr_node.nodeid.Identifier != parent_identifier:
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                    for prop in curr_node.get_properties():
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                        setattr(self, prop.get_browse_name().Name, prop.get_value())
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                    parents = node.get_referenced_nodes(refs=ua.ObjectIds.HasSubtype, direction=ua.BrowseDirection.Inverse, includesubtypes=False)
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                    if len(parents) != 1: # Something went wrong
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                        return None
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                    curr_node = parents[0]
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                self._freeze = True
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    return CustomEvent()
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def _find_parent_eventtype(node):
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    parents = node.get_referenced_nodes(refs=ua.ObjectIds.HasSubtype, direction=ua.BrowseDirection.Inverse, includesubtypes=False)
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    if len(parents) != 1:   # Something went wrong
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        return None
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    if parents[0].nodeid.Identifier in ua.uaevents_auto.IMPLEMNTED_EVENTS.keys():
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        return parents[0].nodeid.Identifier, ua.uaevents_auto.IMPLEMNTED_EVENTS[parents[0].nodeid.Identifier]
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    else:
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        _find_parent_eventtype(parents[0])
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