This change ensures that MQTT messages are retained, allowing Home Assistant to correctly display sensor values even if the openScale app is not running. Additionally, the Home Assistant payload has been updated to use default(none) for sensor values. This prevents errors when a sensor value is not available.

Author: oliexdev

src/app/src/main/java/com/health/openscale/sync/core/sync/MQTTSync.kt

@@ -68,9 +68,9 @@ class MQTTSync(private val mqttClient: Mqtt5BlockingClient) : SyncInterface() {
 
     fun publishLastMeasurement(measurement: OpenScaleMeasurement?): SyncResult<Unit> {
         return if (measurement != null) {
-            publishMeasurement(measurement, "openScaleSync/measurements/last")
+            publishMeasurement(measurement, "openScaleSync/measurements/last", true)
         } else {
-            publishMessage(mapOf<String, Any>(), "openScaleSync/measurements/last")
+            publishMessage(mapOf<String, Any>(), "openScaleSync/measurements/last", true)
         }
     }
 
@@ -135,11 +135,12 @@ class MQTTSync(private val mqttClient: Mqtt5BlockingClient) : SyncInterface() {
         }
     }
 
-    private fun publishMeasurement(measurement: OpenScaleMeasurement, topic: String) : SyncResult<Unit> {
+    private fun publishMeasurement(measurement: OpenScaleMeasurement, topic: String, retain : Boolean = false) : SyncResult<Unit> {
         val payload = gson.toJson(measurement).toByteArray()
         val publish = Mqtt5Publish.builder()
             .topic(topic)
             .payload(payload)
+            .retain(retain)
             .build()
         val result = mqttClient.publish(publish)
         if (result.error.isPresent) {
@@ -149,11 +150,12 @@ class MQTTSync(private val mqttClient: Mqtt5BlockingClient) : SyncInterface() {
         }
     }
 
-    private fun publishMessage(message: Map<String, Any>, topic: String) : SyncResult<Unit> {
+    private fun publishMessage(message: Map<String, Any>, topic: String, retain : Boolean = false) : SyncResult<Unit> {
         val payload = gson.toJson(message).toByteArray()
         val publish = Mqtt5Publish.builder()
             .topic(topic)
             .payload(payload)
+            .retain(retain)
             .build()
         val result = mqttClient.publish(publish)
         if (result.error.isPresent) {
@@ -163,10 +165,11 @@ class MQTTSync(private val mqttClient: Mqtt5BlockingClient) : SyncInterface() {
         }
     }
 
-    private fun publishMessage(value : Boolean, topic: String) : SyncResult<Unit> {
+    private fun publishMessage(value : Boolean, topic: String, retain : Boolean = false) : SyncResult<Unit> {
         val publish = Mqtt5Publish.builder()
             .topic(topic)
             .payload(value.toString().toByteArray())
+            .retain(retain)
             .build()
         val result = mqttClient.publish(publish)
         if (result.error.isPresent) {

src/app/src/main/res/raw/homeassistant_payload.json

@@ -15,44 +15,44 @@
       "platform": "sensor",
       "device_class": "weight",
       "unit_of_measurement": "kg",
-      "value_template": "{{ value_json.weight }}",
+      "value_template": "{{ value_json.weight | default(none) }}",
       "unique_id": "openscale_weight"
     },
     "openscale_fat": {
       "name": "Body fat",
       "platform": "sensor",
       "unit_of_measurement": "%",
-      "value_template": "{{ value_json.fat }}",
+      "value_template": "{{ value_json.fat | default(none) }}",
       "unique_id": "openscale_fat"
     },
     "openscale_muscle": {
       "name": "Muscle",
       "platform": "sensor",
       "unit_of_measurement": "%",
-      "value_template": "{{ value_json.muscle }}",
+      "value_template": "{{ value_json.muscle | default(none) }}",
       "unique_id": "openscale_muscle"
     },
     "openscale_water": {
       "name": "Total body water",
       "platform": "sensor",
       "device_class": "moisture",
       "unit_of_measurement": "%",
-      "value_template": "{{ value_json.water }}",
+      "value_template": "{{ value_json.water | default(none) }}",
       "unique_id": "openscale_water"
     },
     "openscale_measurement_date": {
       "name": "Measurement date",
       "platform": "sensor",
       "entity_category": "diagnostic",
       "device_class": "timestamp",
-      "value_template": "{{ value_json.date }}",
+      "value_template": "{{ value_json.date | default(none) }}",
       "unique_id": "openscale_date"
     },
     "openscale_measurement_id": {
       "name": "Measurement id",
       "platform": "sensor",
       "entity_category": "diagnostic",
-      "value_template": "{{ value_json.id }}",
+      "value_template": "{{ value_json.id | default(none) }}",
       "unique_id": "openscale_id"
     }
   },