[mqtt] Use register_apply_condition for mqtt.connected (#19561)

esphome/components/mqtt/__init__.py

@@ -1,5 +1,4 @@
 from esphome import automation
-from esphome.automation import Condition
 import esphome.codegen as cg
 from esphome.components import logger, socket
 from esphome.components.esp32 import (
@@ -135,7 +134,6 @@ MQTTDisconnectTrigger = mqtt_ns.class_(
     "MQTTDisconnectTrigger", automation.Trigger.template(MQTTClientDisconnectReason)
 )
 MQTTComponent = mqtt_ns.class_("MQTTComponent", cg.Component)
-MQTTConnectedCondition = mqtt_ns.class_("MQTTConnectedCondition", Condition)
 
 MQTTAlarmControlPanelComponent = mqtt_ns.class_(
     "MQTTAlarmControlPanelComponent", MQTTComponent
@@ -599,18 +597,15 @@ async def register_mqtt_component(var, config):
             )
 
 
-@automation.register_condition(
+automation.register_apply_condition(
     "mqtt.connected",
-    MQTTConnectedCondition,
     cv.Schema(
         {
             cv.GenerateID(): cv.use_id(MQTTClientComponent),
         }
     ),
+    "is_connected()",
 )
-async def mqtt_connected_to_code(config, condition_id, template_arg, args):
-    paren = await cg.get_variable(config[CONF_ID])
-    return cg.new_Pvariable(condition_id, template_arg, paren)
 
 
 @automation.register_action(

esphome/components/mqtt/mqtt_client.h

@@ -417,15 +417,6 @@ template<typename... Ts> class MQTTPublishJsonAction final : public Action<Ts...
   MQTTClientComponent *parent_;
 };
 
-template<typename... Ts> class MQTTConnectedCondition final : public Condition<Ts...> {
- public:
-  MQTTConnectedCondition(MQTTClientComponent *parent) : parent_(parent) {}
-  bool check(const Ts &...x) override { return this->parent_->is_connected(); }
-
- protected:
-  MQTTClientComponent *parent_;
-};
-
 template<typename... Ts> class MQTTEnableAction final : public Action<Ts...> {
  public:
   MQTTEnableAction(MQTTClientComponent *parent) : parent_(parent) {}