[api] Fix string lifetime issue in Home Assistant service calls with templated values

esphome/components/api/api.proto

@@ -759,7 +759,7 @@ message SubscribeHomeassistantServicesRequest {
 
 message HomeassistantServiceMap {
   string key = 1;
-  string value = 2;
+  string value = 2 [(no_zero_copy) = true];
 }
 
 message HomeassistantServiceResponse {

esphome/components/api/api_options.proto

@@ -27,4 +27,5 @@ extend google.protobuf.MessageOptions {
 extend google.protobuf.FieldOptions {
     optional string field_ifdef = 1042;
     optional uint32 fixed_array_size = 50007;
+    optional bool no_zero_copy = 50008 [default=false];
 }

esphome/components/api/api_pb2.cpp

@@ -845,11 +845,11 @@ void NoiseEncryptionSetKeyResponse::calculate_size(uint32_t &total_size) const {
 #endif
 void HomeassistantServiceMap::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_string(1, this->key_ref_);
-  buffer.encode_string(2, this->value_ref_);
+  buffer.encode_string(2, this->value);
 }
 void HomeassistantServiceMap::calculate_size(uint32_t &total_size) const {
   ProtoSize::add_string_field(total_size, 1, this->key_ref_.size());
-  ProtoSize::add_string_field(total_size, 1, this->value_ref_.size());
+  ProtoSize::add_string_field(total_size, 1, this->value);
 }
 void HomeassistantServiceResponse::encode(ProtoWriteBuffer buffer) const {
   buffer.encode_string(1, this->service_ref_);

esphome/components/api/api_pb2.h

@@ -1061,8 +1061,7 @@ class HomeassistantServiceMap : public ProtoMessage {
  public:
   StringRef key_ref_{};
   void set_key(const StringRef &ref) { this->key_ref_ = ref; }
-  StringRef value_ref_{};
+  std::string value{};
-  void set_value(const StringRef &ref) { this->value_ref_ = ref; }
   void encode(ProtoWriteBuffer buffer) const override;
   void calculate_size(uint32_t &total_size) const override;
 #ifdef HAS_PROTO_MESSAGE_DUMP

esphome/components/api/api_pb2_dump.cpp

@@ -1044,7 +1044,7 @@ void SubscribeHomeassistantServicesRequest::dump_to(std::string &out) const {
 void HomeassistantServiceMap::dump_to(std::string &out) const {
   MessageDumpHelper helper(out, "HomeassistantServiceMap");
   dump_field(out, "key", this->key_ref_);
-  dump_field(out, "value", this->value_ref_);
+  dump_field(out, "value", this->value);
 }
 void HomeassistantServiceResponse::dump_to(std::string &out) const {
   MessageDumpHelper helper(out, "HomeassistantServiceResponse");

esphome/components/api/homeassistant_service.h

@@ -69,22 +69,19 @@ template<typename... Ts> class HomeAssistantServiceCallAction : public Action<Ts
       resp.data.emplace_back();
       auto &kv = resp.data.back();
       kv.set_key(StringRef(it.key));
-      std::string value = it.value.value(x...);
+      kv.value = it.value.value(x...);
-      kv.set_value(StringRef(value));
     }
     for (auto &it : this->data_template_) {
       resp.data_template.emplace_back();
       auto &kv = resp.data_template.back();
       kv.set_key(StringRef(it.key));
-      std::string value = it.value.value(x...);
+      kv.value = it.value.value(x...);
-      kv.set_value(StringRef(value));
     }
     for (auto &it : this->variables_) {
       resp.variables.emplace_back();
       auto &kv = resp.variables.back();
       kv.set_key(StringRef(it.key));
-      std::string value = it.value.value(x...);
+      kv.value = it.value.value(x...);
-      kv.set_value(StringRef(value));
     }
     this->parent_->send_homeassistant_service_call(resp);
   }

script/api_protobuf/api_protobuf.py

@@ -562,11 +562,16 @@ class StringType(TypeInfo):
     @property
     def public_content(self) -> list[str]:
         content: list[str] = []
-        # Add std::string storage if message needs decoding
+
-        if self._needs_decode:
+        # Check if no_zero_copy option is set
+        no_zero_copy = get_field_opt(self._field, pb.no_zero_copy, False)
+
+        # Add std::string storage if message needs decoding OR if no_zero_copy is set
+        if self._needs_decode or no_zero_copy:
             content.append(f"std::string {self.field_name}{{}};")
 
-        if self._needs_encode:
+        # Only add StringRef if encoding is needed AND no_zero_copy is not set
+        if self._needs_encode and not no_zero_copy:
             content.extend(
                 [
                     # Add StringRef field if message needs encoding
@@ -581,13 +586,28 @@ class StringType(TypeInfo):
 
     @property
     def encode_content(self) -> str:
-        return f"buffer.encode_string({self.number}, this->{self.field_name}_ref_);"
+        # Check if no_zero_copy option is set
+        no_zero_copy = get_field_opt(self._field, pb.no_zero_copy, False)
+
+        if no_zero_copy:
+            # Use the std::string directly
+            return f"buffer.encode_string({self.number}, this->{self.field_name});"
+        else:
+            # Use the StringRef
+            return f"buffer.encode_string({self.number}, this->{self.field_name}_ref_);"
 
     def dump(self, name):
+        # Check if no_zero_copy option is set
+        no_zero_copy = get_field_opt(self._field, pb.no_zero_copy, False)
+
         # If name is 'it', this is a repeated field element - always use string
         if name == "it":
             return "append_quoted_string(out, StringRef(it));"
 
+        # If no_zero_copy is set, always use std::string
+        if no_zero_copy:
+            return f'out.append("\'").append(this->{self.field_name}).append("\'");'
+
         # For SOURCE_CLIENT only, always use std::string
         if not self._needs_encode:
             return f'out.append("\'").append(this->{self.field_name}).append("\'");'
@@ -607,6 +627,13 @@ class StringType(TypeInfo):
 
     @property
     def dump_content(self) -> str:
+        # Check if no_zero_copy option is set
+        no_zero_copy = get_field_opt(self._field, pb.no_zero_copy, False)
+
+        # If no_zero_copy is set, always use std::string
+        if no_zero_copy:
+            return f'dump_field(out, "{self.name}", this->{self.field_name});'
+
         # For SOURCE_CLIENT only, use std::string
         if not self._needs_encode:
             return f'dump_field(out, "{self.name}", this->{self.field_name});'
@@ -622,8 +649,11 @@ class StringType(TypeInfo):
         return o
 
     def get_size_calculation(self, name: str, force: bool = False) -> str:
-        # For SOURCE_CLIENT only messages, use the string field directly
+        # Check if no_zero_copy option is set
-        if not self._needs_encode:
+        no_zero_copy = get_field_opt(self._field, pb.no_zero_copy, False)
+
+        # For SOURCE_CLIENT only messages or no_zero_copy, use the string field directly
+        if not self._needs_encode or no_zero_copy:
             return self._get_simple_size_calculation(name, force, "add_string_field")
 
         # Check if this is being called from a repeated field context