Reimplemented gridPower to keep the binding backwards compatible

Fixes openhab#18148

Signed-off-by: Daniel Kötting <[email protected]>

Author: Daniel Kötting

bundles/org.openhab.binding.evcc/src/main/java/org/openhab/binding/evcc/internal/EvccHandler.java

@@ -29,12 +29,7 @@
 import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.binding.evcc.internal.api.EvccAPI;
 import org.openhab.binding.evcc.internal.api.EvccApiException;
-import org.openhab.binding.evcc.internal.api.dto.Battery;
-import org.openhab.binding.evcc.internal.api.dto.Loadpoint;
-import org.openhab.binding.evcc.internal.api.dto.PV;
-import org.openhab.binding.evcc.internal.api.dto.Plan;
-import org.openhab.binding.evcc.internal.api.dto.Result;
-import org.openhab.binding.evcc.internal.api.dto.Vehicle;
+import org.openhab.binding.evcc.internal.api.dto.*;
 import org.openhab.core.i18n.TimeZoneProvider;
 import org.openhab.core.library.CoreItemFactory;
 import org.openhab.core.library.types.DateTimeType;
@@ -712,7 +707,12 @@ private void updateChannelsGeneral() {
         }
         boolean gridConfigured = this.gridConfigured;
         if (gridConfigured) {
-            float gridPower = ((result.getGrid().getPower() == null) ? 0.0f : result.getGrid().getPower());
+            // handling gridPower prior to changes in evcc version 0.133.0
+            float gridPower = ((result.getGridPower() == null) ? 0.0f : result.getGridPower());
+            Grid grid = result.getGrid();
+            if (grid != null) {
+                gridPower = ((grid.getPower() == null) ? 0.0f : grid.getPower());
+            }
             channel = new ChannelUID(uid, CHANNEL_GROUP_ID_GENERAL, CHANNEL_GRID_POWER);
             updateState(channel, new QuantityType<>(gridPower, Units.WATT));
         }

bundles/org.openhab.binding.evcc/src/main/java/org/openhab/binding/evcc/internal/api/dto/Result.java

@@ -49,6 +49,9 @@ public class Result {
     @SerializedName("batteryMode")
     private String batteryMode;
 
+    @SerializedName("gridPower")
+    private Float gridPower;
+
     @SerializedName("grid")
     private Grid grid;
 
@@ -161,6 +164,13 @@ public String getBatteryMode() {
         return batteryMode;
     }
 
+    /**
+     * @return gridPower (before evcc version 0.133.0)
+     */
+    public Float getGridPower() {
+        return gridPower;
+    }
+
     /**
      * @return all grid related values
      */