add new parameter hasChild and set with connection id

dbm/subscribe.go

@@ -1,6 +1,8 @@
 package dbm
 
 import (
+	"fmt"
+
 	json_dataModels "github.com/tecamino/tecamino-json_data/models"
 )
 
@@ -18,7 +20,17 @@ func (d *DBMHandler) Subscribe(req *json_dataModels.Request, id string) {
 	resp.Id = req.Id
 
 	for _, sub := range req.Subscribe {
-		for _, dp := range d.DBM.QueryDatapoints(sub.Depth, sub.Uuid, sub.Path) {
+		dps := d.DBM.QueryDatapoints(sub.Depth, sub.Uuid, sub.Path)
+
+		if len(dps) == 0 {
+			resp.SetError()
+			if resp.Message == "" {
+				resp.SetMessage(fmt.Sprintf("datapoint %s not found", sub.Path))
+			}
+			continue
+		}
+
+		for _, dp := range dps {
 			if sub.Driver != "" {
 				if dp.Drivers == nil || dp.Drivers[sub.Driver] == nil {
 					continue
@@ -26,11 +38,12 @@ func (d *DBMHandler) Subscribe(req *json_dataModels.Request, id string) {
 			}
 			dp.AddSubscribtion(id, sub)
 			resp.AddSubscription(json_dataModels.Subscription{
-				Uuid:    dp.Uuid,
-				Path:    dp.Path,
-				Value:   dp.Value,
-				Driver:  sub.Driver,
-				Drivers: &dp.Drivers,
+				Uuid:     dp.Uuid,
+				Path:     dp.Path,
+				Value:    dp.Value,
+				HasChild: dp.Datapoints != nil,
+				Driver:   sub.Driver,
+				Drivers:  &dp.Drivers,
 			})
 		}
 	}