FreeOpcUa /
opcua-asyncio
| Conditions | 14 |
| Total Lines | 87 |
| Code Lines | 71 |
| Lines | 0 |
| Ratio | 0 % |
| Changes | 0 | ||
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:
If many parameters/temporary variables are present:
Complex classes like asyncua.common.instantiate_util._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.
Methods with many parameters are not only hard to understand, but their parameters also often become inconsistent when you need more, or different data.
There are several approaches to avoid long parameter lists:
| 1 | """ |
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| 44 | async def _instantiate_node(server, |
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| 45 | node_type, |
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| 46 | parentid, |
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| 47 | rdesc, |
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| 48 | nodeid, |
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| 49 | bname, |
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| 50 | dname=None, |
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| 51 | recursive=True, |
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| 52 | instantiate_optional=True): |
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| 53 | """ |
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| 54 | instantiate a node type under parent |
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| 55 | """ |
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| 56 | addnode = ua.AddNodesItem() |
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| 57 | addnode.RequestedNewNodeId = nodeid |
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| 58 | addnode.BrowseName = bname |
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| 59 | addnode.ParentNodeId = parentid |
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| 60 | addnode.ReferenceTypeId = rdesc.ReferenceTypeId |
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| 61 | addnode.TypeDefinition = rdesc.TypeDefinition |
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| 62 | |||
| 63 | if rdesc.NodeClass in (ua.NodeClass.Object, ua.NodeClass.ObjectType): |
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| 64 | addnode.NodeClass = ua.NodeClass.Object |
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| 65 | await _read_and_copy_attrs(node_type, ua.ObjectAttributes(), addnode) |
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| 66 | |||
| 67 | elif rdesc.NodeClass in (ua.NodeClass.Variable, ua.NodeClass.VariableType): |
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| 68 | addnode.NodeClass = ua.NodeClass.Variable |
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| 69 | await _read_and_copy_attrs(node_type, ua.VariableAttributes(), addnode) |
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| 70 | elif rdesc.NodeClass in (ua.NodeClass.Method,): |
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| 71 | addnode.NodeClass = ua.NodeClass.Method |
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| 72 | await _read_and_copy_attrs(node_type, ua.MethodAttributes(), addnode) |
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| 73 | elif rdesc.NodeClass in (ua.NodeClass.DataType,): |
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| 74 | addnode.NodeClass = ua.NodeClass.DataType |
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| 75 | await _read_and_copy_attrs(node_type, ua.DataTypeAttributes(), addnode) |
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| 76 | else: |
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| 77 | logger.error("Instantiate: Node class not supported: %s", rdesc.NodeClass) |
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| 78 | raise RuntimeError("Instantiate: Node class not supported") |
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| 79 | if dname is not None: |
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| 80 | addnode.NodeAttributes.DisplayName = dname |
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| 81 | |||
| 82 | res = (await server.add_nodes([addnode]))[0] |
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| 83 | added_nodes = [res.AddedNodeId] |
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| 84 | |||
| 85 | if recursive: |
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| 86 | parents = await get_node_supertypes(node_type, includeitself=True) |
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| 87 | node = make_node(server, res.AddedNodeId) |
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| 88 | for parent in parents: |
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| 89 | descs = await parent.get_children_descriptions(includesubtypes=False) |
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| 90 | for c_rdesc in descs: |
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| 91 | # skip items that already exists, prefer the 'lowest' one in object hierarchy |
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| 92 | if not await is_child_present(node, c_rdesc.BrowseName): |
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| 93 | c_node_type = make_node(server, c_rdesc.NodeId) |
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| 94 | refs = await c_node_type.get_referenced_nodes(refs=ua.ObjectIds.HasModellingRule) |
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| 95 | if not refs: |
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| 96 | # spec says to ignore nodes without modelling rules |
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| 97 | logger.info("Instantiate: Skip node without modelling rule %s as part of %s", |
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| 98 | c_rdesc.BrowseName, addnode.BrowseName) |
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| 99 | continue |
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| 100 | # exclude nodes with optional ModellingRule if requested |
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| 101 | if refs[0].nodeid in (ua.NodeId(ua.ObjectIds.ModellingRule_Optional), ua.NodeId(ua.ObjectIds.ModellingRule_OptionalPlaceholder)): |
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| 102 | # instatiate optionals |
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| 103 | if not instantiate_optional: |
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| 104 | logger.info("Instantiate: Skip optional node %s as part of %s", c_rdesc.BrowseName, |
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| 105 | addnode.BrowseName) |
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| 106 | continue |
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| 107 | # if root node being instantiated has a String NodeId, create the children with a String NodeId |
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| 108 | if res.AddedNodeId.NodeIdType is ua.NodeIdType.String: |
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| 109 | inst_nodeid = res.AddedNodeId.Identifier + "." + c_rdesc.BrowseName.Name |
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| 110 | nodeids = await _instantiate_node( |
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| 111 | server, |
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| 112 | c_node_type, |
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| 113 | res.AddedNodeId, |
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| 114 | c_rdesc, |
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| 115 | nodeid=ua.NodeId(identifier=inst_nodeid, namespaceidx=res.AddedNodeId.NamespaceIndex), |
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| 116 | bname=c_rdesc.BrowseName, |
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| 117 | instantiate_optional=instantiate_optional |
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| 118 | ) |
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| 119 | else: |
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| 120 | nodeids = await _instantiate_node( |
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| 121 | server, |
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| 122 | c_node_type, |
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| 123 | res.AddedNodeId, |
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| 124 | c_rdesc, |
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| 125 | nodeid=ua.NodeId(namespaceidx=res.AddedNodeId.NamespaceIndex), |
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| 126 | bname=c_rdesc.BrowseName, |
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| 127 | instantiate_optional=instantiate_optional |
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| 128 | ) |
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| 129 | added_nodes.extend(nodeids) |
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| 130 | return added_nodes |
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| 131 |
