add Client.set_values for wrtting multiple node values at once

asyncua/client/client.py

@@ -13,6 +13,7 @@ from ..common.subscription import Subscription
 from ..common.shortcuts import Shortcuts
 from ..common.structures import load_type_definitions, load_enums
 from ..common.utils import create_nonce
+from ..common.ua_utils import value_to_datavalue
 from ..crypto import uacrypto, security_policies
 
 _logger = logging.getLogger(__name__)
@@ -28,7 +29,6 @@ class Client:
     use UaClient object, available as self.uaclient
     which offers the raw OPC-UA services interface.
     """
-
     def __init__(self, url: str, timeout: int = 4, loop=None):
         """
         :param url: url of the server.
@@ -78,9 +78,7 @@ class Client:
         """
         _logger.info("find_endpoint %r %r %r", endpoints, security_mode, policy_uri)
         for ep in endpoints:
-            if (ep.EndpointUrl.startswith(ua.OPC_TCP_SCHEME) and
-                    ep.SecurityMode == security_mode and
-                    ep.SecurityPolicyUri == policy_uri):
+            if (ep.EndpointUrl.startswith(ua.OPC_TCP_SCHEME) and ep.SecurityMode == security_mode and ep.SecurityPolicyUri == policy_uri):
                 return ep
         raise ua.UaError("No matching endpoints: {0}, {1}".format(security_mode, policy_uri))
 
@@ -117,11 +115,12 @@ class Client:
             raise ua.UaError("Wrong format: `{}`, expected at least 4 comma-separated values".format(string))
         policy_class = getattr(security_policies, "SecurityPolicy{}".format(parts[0]))
         mode = getattr(ua.MessageSecurityMode, parts[1])
-        return await self.set_security(
-            policy_class, parts[2], parts[3], parts[4] if len(parts) >= 5 else None, mode
-        )
+        return await self.set_security(policy_class, parts[2], parts[3], parts[4] if len(parts) >= 5 else None, mode)
 
-    async def set_security(self, policy, certificate_path: str, private_key_path: str,
+    async def set_security(self,
+                           policy,
+                           certificate_path: str,
+                           private_key_path: str,
                            server_certificate_path: str = None,
                            mode: ua.MessageSecurityMode = ua.MessageSecurityMode.SignAndEncrypt):
         """
@@ -580,8 +579,18 @@ class Client:
 
     async def get_values(self, nodes):
         """
-        Read the value of multiple nodes in one roundtrip.
+        Read the value of multiple nodes in one ua call.
         """
-        nodes = [node.nodeid for node in nodes]
-        results = await self.uaclient.get_attribute(nodes, ua.AttributeIds.Value)
+        nodeids = [node.nodeid for node in nodes]
+        results = await self.uaclient.get_attributes(nodeids, ua.AttributeIds.Value)
         return [result.Value.Value for result in results]
+
+    async def set_values(self, nodes, values):
+        """
+        Write values to multiple nodes in one ua call
+        """
+        nodeids = [node.nodeid for node in nodes]
+        dvs = [value_to_datavalue(val) for val in values]
+        results = await self.uaclient.set_attributes(nodeids, dvs, ua.AttributeIds.Value)
+        for result in results:
+            result.check()

asyncua/client/ua_client.py

@@ -642,15 +642,35 @@ class UaClient:
         response.ResponseHeader.ServiceResult.check()
         # nothing to return for this service
 
-    async def get_attribute(self, nodes, attr):
-        self.logger.info("get_attribute")
+    async def get_attributes(self, nodeids, attr):
+        self.logger.info("get_attributes of several nodes")
         request = ua.ReadRequest()
-        for node in nodes:
+        for nodeid in nodeids:
             rv = ua.ReadValueId()
-            rv.NodeId = node
+            rv.NodeId = nodeid
             rv.AttributeId = attr
             request.Parameters.NodesToRead.append(rv)
         data = await self.protocol.send_request(request)
         response = struct_from_binary(ua.ReadResponse, data)
         response.ResponseHeader.ServiceResult.check()
         return response.Results
+
+    async def set_attributes(self, nodeids, datavalues, attributeid=ua.AttributeIds.Value):
+        """
+        Set an attribute of multiple nodes
+        datavalue is a ua.DataValue object
+        """
+        self.logger.info("set_attributes of several nodes")
+        request = ua.WriteRequest()
+        for idx, nodeid in enumerate(nodeids):
+            attr = ua.WriteValue()
+            attr.NodeId = nodeid
+            attr.AttributeId = attributeid
+            attr.Value = datavalues[idx]
+            request.Parameters.NodesToWrite.append(attr)
+        data = await self.protocol.send_request(request)
+        response = struct_from_binary(ua.WriteResponse, data)
+        response.ResponseHeader.ServiceResult.check()
+        return response.Results
+
+

asyncua/common/node.py

@@ -2,11 +2,12 @@
 High level node object, to access node attribute
 and browse address space
 """
-from datetime import datetime
 
 import logging
 
 from asyncua import ua
+from .ua_utils import value_to_datavalue
+
 from .events import Event, get_filter_from_event_type
 from .ua_utils import data_type_to_variant_type
 from .manage_nodes import create_folder, create_object, create_object_type, create_variable, create_variable_type, \
@@ -214,16 +215,8 @@ class Node:
         and you modfy it afterward, then the object in db will be modified without any
         data change event generated
         """
-        datavalue = None
-        if isinstance(value, ua.DataValue):
-            datavalue = value
-        elif isinstance(value, ua.Variant):
-            datavalue = ua.DataValue(value)
-            datavalue.SourceTimestamp = datetime.utcnow()
-        else:
-            datavalue = ua.DataValue(ua.Variant(value, varianttype))
-            datavalue.SourceTimestamp = datetime.utcnow()
-        await self.set_attribute(ua.AttributeIds.Value, datavalue)
+        dv = value_to_datavalue(value, varianttype)
+        await self.set_attribute(ua.AttributeIds.Value, dv)
 
     set_data_value = set_value
 

asyncua/common/ua_utils.py

@@ -13,6 +13,22 @@ from asyncua import ua
 logger = logging.getLogger('__name__')
 
 
+def value_to_datavalue(val, varianttype=None):
+    """
+    convert anyting to a DataValue using varianttype
+    """
+    datavalue = None
+    if isinstance(val, ua.DataValue):
+        datavalue = val
+    elif isinstance(val, ua.Variant):
+        datavalue = ua.DataValue(val)
+        datavalue.SourceTimestamp = datetime.utcnow()
+    else:
+        datavalue = ua.DataValue(ua.Variant(val, varianttype))
+        datavalue.SourceTimestamp = datetime.utcnow()
+    return datavalue
+
+
 def val_to_string(val, truncate=False):
     """
     convert a python object or python-asyncua object to a string
@@ -160,7 +176,7 @@ async def get_node_supertypes(node, includeitself=False, skipbase=True):
     :param node: can be a ua.Node or ua.NodeId
     :param includeitself: include also node to the list
     :param skipbase don't include the toplevel one
-    :returns list of ua.Node, top parent first 
+    :returns list of ua.Node, top parent first
     """
     parents = []
     if includeitself:
@@ -202,7 +218,7 @@ async def is_child_present(node, browsename):
     return if a browsename is present a child from the provide node
     :param node: node wherein to find the browsename
     :param browsename: browsename to search
-    :returns returne True if the browsename is present else False 
+    :returns returne True if the browsename is present else False
     """
     child_descs = await node.get_children_descriptions()
     for child_desc in child_descs:
@@ -229,7 +245,7 @@ async def get_base_data_type(datatype):
     Looks up the base datatype of the provided datatype Node
     The base datatype is either:
     A primitive type (ns=0, i<=21) or a complex one (ns=0 i>21 and i<=30) like Enum and Struct.
-    
+
     Args:
         datatype: NodeId of a datype of a variable
     Returns:
@@ -245,7 +261,7 @@ async def get_base_data_type(datatype):
 
 async def get_nodes_of_namespace(server, namespaces=None):
     """
-    Get the nodes of one or more namespaces .      
+    Get the nodes of one or more namespaces .
     Args:
         server: opc ua server to use
         namespaces: list of string uri or int indexes of the namespace to export

tests/test_client.py

@@ -87,3 +87,24 @@ async def test_custom_enum_struct(server, client):
     val = await myvar.get_value()
     assert 242 == val.IntVal1
     assert ua.ExampleEnum.EnumVal2 == val.EnumVal
+
+
+async def test_multiple_read_and_write(server, client):
+    f = await server.nodes.objects.add_folder(3, 'Multiple_read_write_test')
+    v1 = await f.add_variable(3, "a", 1)
+    await v1.set_writable()
+    v2 = await f.add_variable(3, "b", 2)
+    await v2.set_writable()
+    v3 = await f.add_variable(3, "c", 3)
+    await v3.set_writable()
+    v_ro = await f.add_variable(3, "ro", 3)
+
+    vals = await client.get_values([v1, v2, v3])
+    assert vals == [1, 2, 3]
+    await client.set_values([v1, v2, v3], [4, 5, 6])
+    vals = await client.get_values([v1, v2, v3])
+    assert vals == [4, 5, 6]
+    with pytest.raises(ua.uaerrors.BadUserAccessDenied):
+        await client.set_values([v1, v2, v_ro], [4, 5, 6])
+
+