Completed
Push — master ( 958b45...f72592 )
by Olivier
04:41
created

_instantiate_node()   F

Complexity

Conditions 12

Size

Total Lines 54

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 33
CRAP Score 12.5238

Importance

Changes 4
Bugs 0 Features 0
Metric Value
cc 12
c 4
b 0
f 0
dl 0
loc 54
ccs 33
cts 39
cp 0.8462
crap 12.5238
rs 3.5428

How to fix   Long Method    Complexity   

Long Method

Small methods make your code easier to understand, in particular if combined with a good name. Besides, if your method is small, finding a good name is usually much easier.

For example, if you find yourself adding comments to a method's body, this is usually a good sign to extract the commented part to a new method, and use the comment as a starting point when coming up with a good name for this new method.

Commonly applied refactorings include:

Complexity

Complex classes like _instantiate_node() 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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"""
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Instantiate a new node and its child nodes from a node type.
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"""
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import logging
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from opcua import Node
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from opcua import ua
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from opcua.common import ua_utils
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from opcua.common.copy_node import _rdesc_from_node, _read_and_copy_attrs
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logger = logging.getLogger(__name__)
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def instantiate(parent, node_type, nodeid=None, bname=None, dname=None, idx=0):
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    """
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    instantiate a node type under a parent node.
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    nodeid and browse name of new node can be specified, or just namespace index
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    If they exists children of the node type, such as components, variables and
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    properties are also instantiated
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    """
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    rdesc = _rdesc_from_node(parent, node_type)
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    rdesc.TypeDefinition = node_type.nodeid
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    if nodeid is None:
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        nodeid = ua.NodeId(namespaceidx=idx)  # will trigger automatic node generation in namespace idx
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    if bname is None:
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        bname = rdesc.BrowseName
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    elif isinstance(bname, str):
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        bname = ua.QualifiedName.from_string(bname)
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    nodeids = _instantiate_node(parent.server, parent.nodeid, rdesc, nodeid, bname, dname=dname)
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    return [Node(parent.server, nid) for nid in nodeids]
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def _instantiate_node(server, parentid, rdesc, nodeid, bname, dname=None, recursive=True):
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    """
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    instantiate a node type under parent
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    """
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    node_type = Node(server, rdesc.NodeId)
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    refs = node_type.get_referenced_nodes(refs=ua.ObjectIds.HasModellingRule)
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    # skip optional elements
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    if len(refs) == 1 and refs[0].nodeid == ua.NodeId(ua.ObjectIds.ModellingRule_Optional):
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        return []
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    addnode = ua.AddNodesItem()
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    addnode.RequestedNewNodeId = nodeid
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    addnode.BrowseName = bname
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    addnode.ParentNodeId = parentid
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    addnode.ReferenceTypeId = rdesc.ReferenceTypeId
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    addnode.TypeDefinition = rdesc.TypeDefinition
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    if rdesc.NodeClass in (ua.NodeClass.Object, ua.NodeClass.ObjectType):
57 1
        addnode.NodeClass = ua.NodeClass.Object
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        _read_and_copy_attrs(node_type, ua.ObjectAttributes(), addnode)
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    elif rdesc.NodeClass in (ua.NodeClass.Variable, ua.NodeClass.VariableType):
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        addnode.NodeClass = ua.NodeClass.Variable
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        _read_and_copy_attrs(node_type, ua.VariableAttributes(), addnode)
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    elif rdesc.NodeClass in (ua.NodeClass.Method,):
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        addnode.NodeClass = ua.NodeClass.Method
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        _read_and_copy_attrs(node_type, ua.MethodAttributes(), addnode)
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    else:
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        logger.warning("Instantiate: Node class not supported: %s", rdesc.NodeClass)
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        return
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    if dname is not None:
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        addnode.NodeAttributes.DisplayName = dname
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    res = server.add_nodes([addnode])[0]
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    added_nodes = [res.AddedNodeId]
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    if recursive:
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        parents = ua_utils.get_node_supertypes(node_type, includeitself=True)
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        node = Node(server, res.AddedNodeId)
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        for parent in parents:
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            descs = parent.get_children_descriptions(includesubtypes=False)
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            for c_rdesc in descs:
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                # skip items that already exists, prefer the 'lowest' one in object hierarchy
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                if not ua_utils.is_child_present(node, c_rdesc.BrowseName):
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                    # if root node being instantiated has a String NodeId, create the children with a String NodeId
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                    if res.AddedNodeId.NodeIdType is ua.NodeIdType.String:
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                        inst_nodeid = res.AddedNodeId.Identifier + "." + c_rdesc.BrowseName.Name
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                        nodeids = _instantiate_node(server, res.AddedNodeId, c_rdesc, nodeid=ua.NodeId(identifier=inst_nodeid, namespaceidx=res.AddedNodeId.NamespaceIndex), bname=c_rdesc.BrowseName)
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                    else:
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                        nodeids = _instantiate_node(server, res.AddedNodeId, c_rdesc, nodeid=ua.NodeId(namespaceidx=res.AddedNodeId.NamespaceIndex), bname=c_rdesc.BrowseName)
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                    added_nodes.extend(nodeids)
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    return added_nodes
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