add method:translate relative path of browse name to node id

examples/translate/translate.go

@@ -0,0 +1,42 @@
+// Copyright 2018-2019 opcua authors. All rights reserved.
+// Use of this source code is governed by a MIT-style license that can be
+// found in the LICENSE file.
+
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+
+	"github.com/gopcua/opcua"
+	"github.com/gopcua/opcua/debug"
+	"github.com/gopcua/opcua/id"
+	"github.com/gopcua/opcua/ua"
+)
+
+func main() {
+	endpoint := flag.String("endpoint", "opc.tcp://localhost:4840", "OPC UA Endpoint URL")
+	ns := flag.Int("namespace", 0, "namespace of node")
+	nodePath := flag.String("path", "device_led.temperature", "path of a node's browse name")
+	flag.BoolVar(&debug.Enable, "debug", false, "enable debug logging")
+
+	flag.Parse()
+	log.SetFlags(0)
+
+	ctx := context.Background()
+
+	c := opcua.NewClient(*endpoint)
+	if err := c.Connect(ctx); err != nil {
+		log.Fatal(err)
+	}
+	defer c.Close()
+
+	root := c.Node(ua.NewTwoByteNodeID(id.ObjectsFolder))
+	nodeId, err := root.TranslateBrowsePathInSameNamespaceToNodeId(uint8(*ns), *nodePath)
+	if err != nil {
+		log.Fatal(err)
+	}
+	fmt.Println(nodeId)
+}

node.go

@@ -5,9 +5,10 @@
 package opcua
 
 import (
-	"time"
-
+	"github.com/gopcua/opcua/id"
 	"github.com/gopcua/opcua/ua"
+	"strings"
+	"time"
 )
 
 // Node is a high-level object to interact with a node in the
@@ -116,7 +117,7 @@ func (n *Node) Attribute(attrID ua.AttributeID) (*ua.Variant, error) {
 	return value, nil
 }
 
-// References retrns all references for the node.
+// References returns all references for the node.
 // todo(fs): this is not complete since it only returns the
 // todo(fs): top-level reference at this point.
 func (n *Node) References(refs *ua.NodeID) (*ua.BrowseResponse, error) {
@@ -141,3 +142,59 @@ func (n *Node) References(refs *ua.NodeID) (*ua.BrowseResponse, error) {
 	return n.c.Browse(req)
 	// implement browse_next
 }
+
+//TranslateBrowsePathToNodeId translate an array of browseName segment to NodeID
+func (n *Node) TranslateBrowsePathToNodeId(pathNames []*ua.QualifiedName) (*ua.NodeID, error) {
+	req := ua.TranslateBrowsePathsToNodeIDsRequest{
+		RequestHeader: &ua.RequestHeader{AuthenticationToken: ua.NewFourByteNodeID(0, id.TranslateBrowsePathsToNodeIDsRequest_Encoding_DefaultBinary)},
+		BrowsePaths: []*ua.BrowsePath{
+			{
+				StartingNode: n.ID,
+				RelativePath: &ua.RelativePath{
+					Elements: []*ua.RelativePathElement{},
+				},
+			},
+		}}
+
+	for _, pathSegment := range pathNames {
+		req.BrowsePaths[0].RelativePath.Elements = append(req.BrowsePaths[0].RelativePath.Elements,
+			&ua.RelativePathElement{ReferenceTypeID: ua.NewTwoByteNodeID(id.HierarchicalReferences),
+				IsInverse:       false,
+				IncludeSubtypes: true,
+				TargetName:      pathSegment,
+			},
+		)
+	}
+
+	var nodeID *ua.NodeID
+	err := n.c.Send(&req, func(i interface{}) error {
+		if resp, ok := i.(*ua.TranslateBrowsePathsToNodeIDsResponse); ok {
+			if len(resp.Results) == 0 {
+				return ua.StatusBadUnexpectedError
+			}
+
+			if resp.Results[0].StatusCode != ua.StatusOK {
+				return resp.Results[0].StatusCode
+			}
+
+			if len(resp.Results[0].Targets) == 0 {
+				return ua.StatusBadUnexpectedError
+			}
+			nodeID = resp.Results[0].Targets[0].TargetID.NodeID
+			return nil
+		}
+		return ua.StatusBadUnexpectedError
+	})
+	return nodeID, err
+}
+
+//TranslateBrowsePathInSameNamespaceToNodeId translate a browseName to NodeID
+//here we assume that all parts of path are in the same namespace
+func (n *Node) TranslateBrowsePathInSameNamespaceToNodeId(ns uint8, browseNamePath string) (*ua.NodeID, error) {
+	segments := strings.Split(browseNamePath, ".")
+	var pathNames []*ua.QualifiedName
+	for _, segment := range segments {
+		pathNames = append(pathNames, &ua.QualifiedName{NamespaceIndex: uint16(ns), Name: segment})
+	}
+	return n.TranslateBrowsePathToNodeId(pathNames)
+}