finish client implementation for custom structures

Author: oroulet

opcua/client/client.py

@@ -534,21 +534,38 @@ def register_namespace(self, uri):
         ns_node.set_value(uries)
         return len(uries) - 1
 
-    def import_structures(self, nodes=None):
+    def import_and_register_structures(self, nodes=None):
         """
         Download xml from given variable node defining custom structures.
-        If no node is given, attemps to import variables from
+        If no no node is given, attemps to import variables from all nodes under
+        "0:OPC Binary"
+        the code is generated and imported on the fly. If you know the structures
+        are not going to be modified it is safer to copy the generated files
+        and include them in you code
         """
-        if not nodes:
+        if nodes is None:
             nodes = []
-            opc_bin = self.nodes.base_data_type.get_child("0:OPC Binary")
-            for desc in opc_bin.get_children_descriptions():
-                if desc.BrowseName != ua.QualifiedName("opc.Ua"):
+            for desc in self.nodes.opc_binary.get_children_descriptions():
+                if desc.BrowseName != ua.QualifiedName("Opc.Ua"):
                     nodes.append(self.get_node(desc.NodeId))
+        self.logger.info("Importing structures from nodes: %s", nodes)
 
         for node in nodes:
             xml = node.get_value()
-            gen = StructGenerator(xml, name)
+            xml = xml.decode("utf-8")
+            #with open("titi.xml", "w") as f:
+                #f.write(xml)
+            name = "structures_" + node.get_browse_name().Name
+            gen = StructGenerator()
+            gen.make_model_from_string(xml)
+            structs_dict = gen.save_and_import(name + ".py")
+            # register classes
+            for desc in node.get_children_descriptions():
+                if desc.BrowseName.Name in structs_dict:
+                    self.logger.info("registring new structure: %: %s", desc.NodeId, desc.BrowseName.Name)
+                    ua.extension_object_classes[desc.NodeId] = structs_dict[desc.BrowseName.Name]
+                    ua.extension_object_ids[desc.BrowseName.Name] = desc.NodeId
+
 
 
 

opcua/common/shortcuts.py

@@ -24,3 +24,4 @@ def __init__(self, server):
         self.variable_types = Node(server, ObjectIds.VariableTypesFolder)
         self.object_types = Node(server, ObjectIds.ObjectTypesFolder)
         self.namespace_array = Node(server, ObjectIds.Server_NamespaceArray)
+        self.opc_binary = Node(server, ObjectIds.OPCBinarySchema_TypeSystem)

opcua/common/structures_generator.py

@@ -4,6 +4,9 @@
 for custom structures
 """
 
+import os
+import importlib
+
 from lxml import objectify
 
 
@@ -123,15 +126,19 @@ def __init__(self, name):
 
 
 class StructGenerator(object):
-    def __init__(self, path, output):
-        self.path = path
-        self.output = output
+    def __init__(self):
         self.model = []
-        self._file = None
 
-    def _make_model(self):
-        obj = objectify.parse(self.path)
+    def make_model_from_string(self, xml):
+        obj = objectify.fromstring(xml)
+        self._make_model(obj)
+
+    def make_model_from_file(self, path):
+        obj = objectify.parse(path)
         root = obj.getroot()
+        self._make_model(root)
+
+    def _make_model(self, root):
         for child in root.iter("{*}StructuredType"):
             struct = Struct(child.get("Name"))
             array = False
@@ -152,23 +159,29 @@ def _make_model(self):
                 struct.fields.append(field)
             self.model.append(struct)
 
-    def run(self):
-        self._make_model()
-        self._file = open(self.output, "wt")
-        self._make_header()
+    def save_to_file(self, path):
+        _file = open(path, "wt")
+        self._make_header(_file)
         for struct in self.model:
-            self._file.write(struct.get_code())
-        self._file.close()
+            _file.write(struct.get_code())
+        _file.close()
+
+    def save_and_import(self, path):
+        self.save_to_file(path)
+        name = os.path.basename(path)
+        name = os.path.splitext(name)[0]
+        mymodule = importlib.import_module(name)
+        mydict = {struct.name: getattr(mymodule, struct.name) for struct in self.model}
+        return mydict
 
     def get_structures(self):
-        self._make_model()
         ld = {}
         for struct in self.model:
             exec(struct.get_code(), ld)
         return ld
 
-    def _make_header(self):
-        self._file.write("""
+    def _make_header(self, _file):
+        _file.write("""
 '''
 THIS FILE IS AUTOGENERATED, DO NOT EDIT!!!
 '''