Add attribute support to Home Assistant sensors (#1770)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>

esphome/components/api/api.proto

@@ -561,6 +561,7 @@ message SubscribeHomeAssistantStateResponse {
   option (id) = 39;
   option (source) = SOURCE_SERVER;
   string entity_id = 1;
+  string attribute = 2;
 }
 
 message HomeAssistantStateResponse {
@@ -570,6 +571,7 @@ message HomeAssistantStateResponse {
 
   string entity_id = 1;
   string state = 2;
+  string attribute = 3;
 }
 
 // ==================== IMPORT TIME ====================

esphome/components/api/api_connection.cpp

@@ -642,8 +642,9 @@ DeviceInfoResponse APIConnection::device_info(const DeviceInfoRequest &msg) {
 }
 void APIConnection::on_home_assistant_state_response(const HomeAssistantStateResponse &msg) {
   for (auto &it : this->parent_->get_state_subs())
-    if (it.entity_id == msg.entity_id)
+    if (it.entity_id == msg.entity_id && it.attribute.value() == msg.attribute) {
       it.callback(msg.state);
+    }
 }
 void APIConnection::execute_service(const ExecuteServiceRequest &msg) {
   bool found = false;
@@ -660,6 +661,7 @@ void APIConnection::subscribe_home_assistant_states(const SubscribeHomeAssistant
   for (auto &it : this->parent_->get_state_subs()) {
     SubscribeHomeAssistantStateResponse resp;
     resp.entity_id = it.entity_id;
+    resp.attribute = it.attribute.value();
     if (!this->send_subscribe_home_assistant_state_response(resp)) {
       this->on_fatal_error();
       return;

esphome/components/api/api_pb2.cpp

@@ -2123,12 +2123,17 @@ bool SubscribeHomeAssistantStateResponse::decode_length(uint32_t field_id, Proto
       this->entity_id = value.as_string();
       return true;
     }
+    case 2: {
+      this->attribute = value.as_string();
+      return true;
+    }
     default:
       return false;
   }
 }
 void SubscribeHomeAssistantStateResponse::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_string(1, this->entity_id);
+  buffer.encode_string(2, this->attribute);
 }
 void SubscribeHomeAssistantStateResponse::dump_to(std::string &out) const {
   char buffer[64];
@@ -2136,6 +2141,10 @@ void SubscribeHomeAssistantStateResponse::dump_to(std::string &out) const {
   out.append("  entity_id: ");
   out.append("'").append(this->entity_id).append("'");
   out.append("\n");
+
+  out.append("  attribute: ");
+  out.append("'").append(this->attribute).append("'");
+  out.append("\n");
   out.append("}");
 }
 bool HomeAssistantStateResponse::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
@@ -2148,6 +2157,10 @@ bool HomeAssistantStateResponse::decode_length(uint32_t field_id, ProtoLengthDel
       this->state = value.as_string();
       return true;
     }
+    case 3: {
+      this->attribute = value.as_string();
+      return true;
+    }
     default:
       return false;
   }
@@ -2155,6 +2168,7 @@ bool HomeAssistantStateResponse::decode_length(uint32_t field_id, ProtoLengthDel
 void HomeAssistantStateResponse::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_string(1, this->entity_id);
   buffer.encode_string(2, this->state);
+  buffer.encode_string(3, this->attribute);
 }
 void HomeAssistantStateResponse::dump_to(std::string &out) const {
   char buffer[64];
@@ -2166,6 +2180,10 @@ void HomeAssistantStateResponse::dump_to(std::string &out) const {
   out.append("  state: ");
   out.append("'").append(this->state).append("'");
   out.append("\n");
+
+  out.append("  attribute: ");
+  out.append("'").append(this->attribute).append("'");
+  out.append("\n");
   out.append("}");
 }
 void GetTimeRequest::encode(ProtoWriteBuffer buffer) const {}

esphome/components/api/api_pb2.h

@@ -557,6 +557,7 @@ class SubscribeHomeAssistantStatesRequest : public ProtoMessage {
 class SubscribeHomeAssistantStateResponse : public ProtoMessage {
  public:
   std::string entity_id{};
+  std::string attribute{};
   void encode(ProtoWriteBuffer buffer) const override;
   void dump_to(std::string &out) const override;
 
@@ -567,6 +568,7 @@ class HomeAssistantStateResponse : public ProtoMessage {
  public:
   std::string entity_id{};
   std::string state{};
+  std::string attribute{};
   void encode(ProtoWriteBuffer buffer) const override;
   void dump_to(std::string &out) const override;
 

esphome/components/api/api_server.cpp

@@ -208,9 +208,11 @@ void APIServer::send_homeassistant_service_call(const HomeassistantServiceRespon
   }
 }
 APIServer::APIServer() { global_api_server = this; }
-void APIServer::subscribe_home_assistant_state(std::string entity_id, std::function<void(std::string)> f) {
+void APIServer::subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
+                                               std::function<void(std::string)> f) {
   this->state_subs_.push_back(HomeAssistantStateSubscription{
       .entity_id = std::move(entity_id),
+      .attribute = std::move(attribute),
       .callback = std::move(f),
   });
 }

esphome/components/api/api_server.h

@@ -71,10 +71,12 @@ class APIServer : public Component, public Controller {
 
   struct HomeAssistantStateSubscription {
     std::string entity_id;
+    optional<std::string> attribute;
     std::function<void(std::string)> callback;
   };
 
-  void subscribe_home_assistant_state(std::string entity_id, std::function<void(std::string)> f);
+  void subscribe_home_assistant_state(std::string entity_id, optional<std::string> attribute,
+                                      std::function<void(std::string)> f);
   const std::vector<HomeAssistantStateSubscription> &get_state_subs() const;
   const std::vector<UserServiceDescriptor *> &get_user_services() const { return this->user_services_; }
 

esphome/components/api/custom_api_device.h

@@ -76,13 +76,13 @@ class CustomAPIDevice {
     global_api_server->register_user_service(service);
   }
 
-  /** Subscribe to the state of an entity from Home Assistant.
+  /** Subscribe to the state (or attribute state) of an entity from Home Assistant.
    *
    * Usage:
    *
    * ```cpp
    * void setup() override {
-   *   subscribe_homeassistant_state(&CustomNativeAPI::on_state_changed, "sensor.weather_forecast");
+   *   subscribe_homeassistant_state(&CustomNativeAPI::on_state_changed, "climate.kitchen", "current_temperature");
    * }
    *
    * void on_state_changed(std::string state) {
@@ -93,17 +93,19 @@ class CustomAPIDevice {
    * @tparam T The class type creating the service, automatically deduced from the function pointer.
    * @param callback The member function to call when the entity state changes.
    * @param entity_id The entity_id to track.
+   * @param attribute The entity state attribute to track.
    */
   template<typename T>
-  void subscribe_homeassistant_state(void (T::*callback)(std::string), const std::string &entity_id) {
+  void subscribe_homeassistant_state(void (T::*callback)(std::string), const std::string &entity_id,
+                                     const std::string &attribute = "") {
     auto f = std::bind(callback, (T *) this, std::placeholders::_1);
-    global_api_server->subscribe_home_assistant_state(entity_id, f);
+    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute), f);
   }
 
-  /** Subscribe to the state of an entity from Home Assistant.
+  /** Subscribe to the state (or attribute state) of an entity from Home Assistant.
    *
    * Usage:
-   *
+   *å
    * ```cpp
    * void setup() override {
    *   subscribe_homeassistant_state(&CustomNativeAPI::on_state_changed, "sensor.weather_forecast");
@@ -117,11 +119,13 @@ class CustomAPIDevice {
    * @tparam T The class type creating the service, automatically deduced from the function pointer.
    * @param callback The member function to call when the entity state changes.
    * @param entity_id The entity_id to track.
+   * @param attribute The entity state attribute to track.
    */
   template<typename T>
-  void subscribe_homeassistant_state(void (T::*callback)(std::string, std::string), const std::string &entity_id) {
+  void subscribe_homeassistant_state(void (T::*callback)(std::string, std::string), const std::string &entity_id,
+                                     const std::string &attribute = "") {
     auto f = std::bind(callback, (T *) this, entity_id, std::placeholders::_1);
-    global_api_server->subscribe_home_assistant_state(entity_id, f);
+    global_api_server->subscribe_home_assistant_state(entity_id, optional<std::string>(attribute), f);
   }
 
   /** Call a Home Assistant service from ESPHome.