[event] Trigger events without building a temporary std::string (#19567)

esphome/components/event/__init__.py

@@ -133,10 +133,17 @@ TRIGGER_EVENT_SCHEMA = cv.Schema(
 )
 
 
+def _event_type_literal(config: ConfigType, value: str) -> str:
+    """A constant event type is a plain literal; trigger() only compares it, so no copy is needed."""
+    return str(cg.safe_exp(value))
+
+
 automation.register_apply_action(
     "event.trigger",
     TRIGGER_EVENT_SCHEMA,
-    automation.ApplyField(CONF_EVENT_TYPE, "trigger", cg.std_string),
+    automation.ApplyField(
+        CONF_EVENT_TYPE, "trigger", cg.std_string, _event_type_literal
+    ),
 )
 
 

esphome/components/event/event.cpp

@@ -7,17 +7,17 @@ namespace esphome::event {
 
 static const char *const TAG = "event";
 
-void Event::trigger(const std::string &event_type) {
+void Event::trigger(const char *event_type) {
   // Linear search with strcmp - faster than std::set for small datasets (1-5 items typical)
   const char *found = nullptr;
   for (const char *type : this->types_) {
-    if (strcmp(type, event_type.c_str()) == 0) {
+    if (strcmp(type, event_type) == 0) {
       found = type;
       break;
     }
   }
   if (found == nullptr) {
-    ESP_LOGE(TAG, "'%s': invalid event type for trigger(): %s", this->get_name().c_str(), event_type.c_str());
+    ESP_LOGE(TAG, "'%s': invalid event type for trigger(): %s", this->get_name().c_str(), event_type);
     return;
   }
   this->last_event_type_ = found;

esphome/components/event/event.h

@@ -21,7 +21,9 @@ namespace esphome::event {
 
 class Event : public EntityBase {
  public:
-  void trigger(const std::string &event_type);
+  /// Trigger an event; the type is matched against the configured types by string compare.
+  void trigger(const char *event_type);
+  void trigger(const std::string &event_type) { this->trigger(event_type.c_str()); }
 
   /// Set the event types supported by this event (from initializer list).
   void set_event_types(std::initializer_list<const char *> event_types) {