Add support for button entities (#2824)

CODEOWNERS

@@ -30,6 +30,7 @@ esphome/components/bang_bang/* @OttoWinter
 esphome/components/binary_sensor/* @esphome/core
 esphome/components/ble_client/* @buxtronix
 esphome/components/bme680_bsec/* @trvrnrth
+esphome/components/button/* @esphome/core
 esphome/components/canbus/* @danielschramm @mvturnho
 esphome/components/cap1188/* @MrEditor97
 esphome/components/captive_portal/* @OttoWinter

esphome/components/api/api.proto

@@ -40,6 +40,7 @@ service APIConnection {
   rpc climate_command (ClimateCommandRequest) returns (void) {}
   rpc number_command (NumberCommandRequest) returns (void) {}
   rpc select_command (SelectCommandRequest) returns (void) {}
+  rpc button_command (ButtonCommandRequest) returns (void) {}
 }
 
 
@@ -944,3 +945,27 @@ message SelectCommandRequest {
   fixed32 key = 1;
   string state = 2;
 }
+
+// ==================== BUTTON ====================
+message ListEntitiesButtonResponse {
+  option (id) = 61;
+  option (source) = SOURCE_SERVER;
+  option (ifdef) = "USE_BUTTON";
+
+  string object_id = 1;
+  fixed32 key = 2;
+  string name = 3;
+  string unique_id = 4;
+
+  string icon = 5;
+  bool disabled_by_default = 6;
+  EntityCategory entity_category = 7;
+}
+message ButtonCommandRequest {
+  option (id) = 62;
+  option (source) = SOURCE_CLIENT;
+  option (ifdef) = "USE_BUTTON";
+  option (no_delay) = true;
+
+  fixed32 key = 1;
+}

esphome/components/api/api_connection.cpp

@@ -674,6 +674,27 @@ void APIConnection::select_command(const SelectCommandRequest &msg) {
 }
 #endif
 
+#ifdef USE_BUTTON
+bool APIConnection::send_button_info(button::Button *button) {
+  ListEntitiesButtonResponse msg;
+  msg.key = button->get_object_id_hash();
+  msg.object_id = button->get_object_id();
+  msg.name = button->get_name();
+  msg.unique_id = get_default_unique_id("button", button);
+  msg.icon = button->get_icon();
+  msg.disabled_by_default = button->is_disabled_by_default();
+  msg.entity_category = static_cast<enums::EntityCategory>(button->get_entity_category());
+  return this->send_list_entities_button_response(msg);
+}
+void APIConnection::button_command(const ButtonCommandRequest &msg) {
+  button::Button *button = App.get_button_by_key(msg.key);
+  if (button == nullptr)
+    return;
+
+  button->press();
+}
+#endif
+
 #ifdef USE_ESP32_CAMERA
 void APIConnection::send_camera_state(std::shared_ptr<esp32_camera::CameraImage> image) {
   if (!this->state_subscription_)

esphome/components/api/api_connection.h

@@ -73,6 +73,10 @@ class APIConnection : public APIServerConnection {
   bool send_select_state(select::Select *select, std::string state);
   bool send_select_info(select::Select *select);
   void select_command(const SelectCommandRequest &msg) override;
+#endif
+#ifdef USE_BUTTON
+  bool send_button_info(button::Button *button);
+  void button_command(const ButtonCommandRequest &msg) override;
 #endif
   bool send_log_message(int level, const char *tag, const char *line);
   void send_homeassistant_service_call(const HomeassistantServiceResponse &call) {

esphome/components/api/api_pb2.cpp

@@ -4147,6 +4147,118 @@ void SelectCommandRequest::dump_to(std::string &out) const {
   out.append("}");
 }
 #endif
+bool ListEntitiesButtonResponse::decode_varint(uint32_t field_id, ProtoVarInt value) {
+  switch (field_id) {
+    case 6: {
+      this->disabled_by_default = value.as_bool();
+      return true;
+    }
+    case 7: {
+      this->entity_category = value.as_enum<enums::EntityCategory>();
+      return true;
+    }
+    default:
+      return false;
+  }
+}
+bool ListEntitiesButtonResponse::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
+  switch (field_id) {
+    case 1: {
+      this->object_id = value.as_string();
+      return true;
+    }
+    case 3: {
+      this->name = value.as_string();
+      return true;
+    }
+    case 4: {
+      this->unique_id = value.as_string();
+      return true;
+    }
+    case 5: {
+      this->icon = value.as_string();
+      return true;
+    }
+    default:
+      return false;
+  }
+}
+bool ListEntitiesButtonResponse::decode_32bit(uint32_t field_id, Proto32Bit value) {
+  switch (field_id) {
+    case 2: {
+      this->key = value.as_fixed32();
+      return true;
+    }
+    default:
+      return false;
+  }
+}
+void ListEntitiesButtonResponse::encode(ProtoWriteBuffer buffer) const {
+  buffer.encode_string(1, this->object_id);
+  buffer.encode_fixed32(2, this->key);
+  buffer.encode_string(3, this->name);
+  buffer.encode_string(4, this->unique_id);
+  buffer.encode_string(5, this->icon);
+  buffer.encode_bool(6, this->disabled_by_default);
+  buffer.encode_enum<enums::EntityCategory>(7, this->entity_category);
+}
+#ifdef HAS_PROTO_MESSAGE_DUMP
+void ListEntitiesButtonResponse::dump_to(std::string &out) const {
+  char buffer[64];
+  out.append("ListEntitiesButtonResponse {\n");
+  out.append("  object_id: ");
+  out.append("'").append(this->object_id).append("'");
+  out.append("\n");
+
+  out.append("  key: ");
+  sprintf(buffer, "%u", this->key);
+  out.append(buffer);
+  out.append("\n");
+
+  out.append("  name: ");
+  out.append("'").append(this->name).append("'");
+  out.append("\n");
+
+  out.append("  unique_id: ");
+  out.append("'").append(this->unique_id).append("'");
+  out.append("\n");
+
+  out.append("  icon: ");
+  out.append("'").append(this->icon).append("'");
+  out.append("\n");
+
+  out.append("  disabled_by_default: ");
+  out.append(YESNO(this->disabled_by_default));
+  out.append("\n");
+
+  out.append("  entity_category: ");
+  out.append(proto_enum_to_string<enums::EntityCategory>(this->entity_category));
+  out.append("\n");
+  out.append("}");
+}
+#endif
+bool ButtonCommandRequest::decode_32bit(uint32_t field_id, Proto32Bit value) {
+  switch (field_id) {
+    case 1: {
+      this->key = value.as_fixed32();
+      return true;
+    }
+    default:
+      return false;
+  }
+}
+void ButtonCommandRequest::encode(ProtoWriteBuffer buffer) const { buffer.encode_fixed32(1, this->key); }
+#ifdef HAS_PROTO_MESSAGE_DUMP
+void ButtonCommandRequest::dump_to(std::string &out) const {
+  char buffer[64];
+  out.append("ButtonCommandRequest {\n");
+  out.append("  key: ");
+  sprintf(buffer, "%u", this->key);
+  out.append(buffer);
+  out.append("\n");
+  out.append("}");
+}
+#endif
 
 }  // namespace api
 }  // namespace esphome

esphome/components/api/api_pb2.h

@@ -1041,6 +1041,36 @@ class SelectCommandRequest : public ProtoMessage {
   bool decode_32bit(uint32_t field_id, Proto32Bit value) override;
   bool decode_length(uint32_t field_id, ProtoLengthDelimited value) override;
 };
+class ListEntitiesButtonResponse : public ProtoMessage {
+ public:
+  std::string object_id{};
+  uint32_t key{0};
+  std::string name{};
+  std::string unique_id{};
+  std::string icon{};
+  bool disabled_by_default{false};
+  enums::EntityCategory entity_category{};
+  void encode(ProtoWriteBuffer buffer) const override;
+#ifdef HAS_PROTO_MESSAGE_DUMP
+  void dump_to(std::string &out) const override;
+#endif
+
+ protected:
+  bool decode_32bit(uint32_t field_id, Proto32Bit value) override;
+  bool decode_length(uint32_t field_id, ProtoLengthDelimited value) override;
+  bool decode_varint(uint32_t field_id, ProtoVarInt value) override;
+};
+class ButtonCommandRequest : public ProtoMessage {
+ public:
+  uint32_t key{0};
+  void encode(ProtoWriteBuffer buffer) const override;
+#ifdef HAS_PROTO_MESSAGE_DUMP
+  void dump_to(std::string &out) const override;
+#endif
+
+ protected:
+  bool decode_32bit(uint32_t field_id, Proto32Bit value) override;
+};
 
 }  // namespace api
 }  // namespace esphome

esphome/components/api/api_pb2_service.cpp

@@ -282,6 +282,16 @@ bool APIServerConnectionBase::send_select_state_response(const SelectStateRespon
 #endif
 #ifdef USE_SELECT
 #endif
+#ifdef USE_BUTTON
+bool APIServerConnectionBase::send_list_entities_button_response(const ListEntitiesButtonResponse &msg) {
+#ifdef HAS_PROTO_MESSAGE_DUMP
+  ESP_LOGVV(TAG, "send_list_entities_button_response: %s", msg.dump().c_str());
+#endif
+  return this->send_message_<ListEntitiesButtonResponse>(msg, 61);
+}
+#endif
+#ifdef USE_BUTTON
+#endif
 bool APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type, uint8_t *msg_data) {
   switch (msg_type) {
     case 1: {
@@ -513,6 +523,17 @@ bool APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type,
       ESP_LOGVV(TAG, "on_select_command_request: %s", msg.dump().c_str());
 #endif
       this->on_select_command_request(msg);
+#endif
+      break;
+    }
+    case 62: {
+#ifdef USE_BUTTON
+      ButtonCommandRequest msg;
+      msg.decode(msg_data, msg_size);
+#ifdef HAS_PROTO_MESSAGE_DUMP
+      ESP_LOGVV(TAG, "on_button_command_request: %s", msg.dump().c_str());
+#endif
+      this->on_button_command_request(msg);
 #endif
       break;
     }
@@ -737,6 +758,19 @@ void APIServerConnection::on_select_command_request(const SelectCommandRequest &
   this->select_command(msg);
 }
 #endif
+#ifdef USE_BUTTON
+void APIServerConnection::on_button_command_request(const ButtonCommandRequest &msg) {
+  if (!this->is_connection_setup()) {
+    this->on_no_setup_connection();
+    return;
+  }
+  if (!this->is_authenticated()) {
+    this->on_unauthenticated_access();
+    return;
+  }
+  this->button_command(msg);
+}
+#endif
 
 }  // namespace api
 }  // namespace esphome

esphome/components/api/api_pb2_service.h

@@ -129,6 +129,12 @@ class APIServerConnectionBase : public ProtoService {
 #endif
 #ifdef USE_SELECT
   virtual void on_select_command_request(const SelectCommandRequest &value){};
+#endif
+#ifdef USE_BUTTON
+  bool send_list_entities_button_response(const ListEntitiesButtonResponse &msg);
+#endif
+#ifdef USE_BUTTON
+  virtual void on_button_command_request(const ButtonCommandRequest &value){};
 #endif
  protected:
   bool read_message(uint32_t msg_size, uint32_t msg_type, uint8_t *msg_data) override;
@@ -171,6 +177,9 @@ class APIServerConnection : public APIServerConnectionBase {
 #endif
 #ifdef USE_SELECT
   virtual void select_command(const SelectCommandRequest &msg) = 0;
+#endif
+#ifdef USE_BUTTON
+  virtual void button_command(const ButtonCommandRequest &msg) = 0;
 #endif
  protected:
   void on_hello_request(const HelloRequest &msg) override;
@@ -209,6 +218,9 @@ class APIServerConnection : public APIServerConnectionBase {
 #ifdef USE_SELECT
   void on_select_command_request(const SelectCommandRequest &msg) override;
 #endif
+#ifdef USE_BUTTON
+  void on_button_command_request(const ButtonCommandRequest &msg) override;
+#endif
 };
 
 }  // namespace api

esphome/components/api/list_entities.cpp

@@ -27,6 +27,9 @@ bool ListEntitiesIterator::on_sensor(sensor::Sensor *sensor) { return this->clie
 #ifdef USE_SWITCH
 bool ListEntitiesIterator::on_switch(switch_::Switch *a_switch) { return this->client_->send_switch_info(a_switch); }
 #endif
+#ifdef USE_BUTTON
+bool ListEntitiesIterator::on_button(button::Button *button) { return this->client_->send_button_info(button); }
+#endif
 #ifdef USE_TEXT_SENSOR
 bool ListEntitiesIterator::on_text_sensor(text_sensor::TextSensor *text_sensor) {
   return this->client_->send_text_sensor_info(text_sensor);

esphome/components/api/list_entities.h

@@ -30,6 +30,9 @@ class ListEntitiesIterator : public ComponentIterator {
 #ifdef USE_SWITCH
   bool on_switch(switch_::Switch *a_switch) override;
 #endif
+#ifdef USE_BUTTON
+  bool on_button(button::Button *button) override;
+#endif
 #ifdef USE_TEXT_SENSOR
   bool on_text_sensor(text_sensor::TextSensor *text_sensor) override;
 #endif

esphome/components/api/subscribe_state.h

@@ -31,6 +31,9 @@ class InitialStateIterator : public ComponentIterator {
 #ifdef USE_SWITCH
   bool on_switch(switch_::Switch *a_switch) override;
 #endif
+#ifdef USE_BUTTON
+  bool on_button(button::Button *button) override { return true; };
+#endif
 #ifdef USE_TEXT_SENSOR
   bool on_text_sensor(text_sensor::TextSensor *text_sensor) override;
 #endif

esphome/components/api/util.cpp

@@ -116,6 +116,21 @@ void ComponentIterator::advance() {
       }
       break;
 #endif
+#ifdef USE_BUTTON
+    case IteratorState::BUTTON:
+      if (this->at_ >= App.get_buttons().size()) {
+        advance_platform = true;
+      } else {
+        auto *button = App.get_buttons()[this->at_];
+        if (button->is_internal()) {
+          success = true;
+          break;
+        } else {
+          success = this->on_button(button);
+        }
+      }
+      break;
+#endif
 #ifdef USE_TEXT_SENSOR
     case IteratorState::TEXT_SENSOR:
       if (this->at_ >= App.get_text_sensors().size()) {

esphome/components/api/util.h

@@ -38,6 +38,9 @@ class ComponentIterator {
 #ifdef USE_SWITCH
   virtual bool on_switch(switch_::Switch *a_switch) = 0;
 #endif
+#ifdef USE_BUTTON
+  virtual bool on_button(button::Button *button) = 0;
+#endif
 #ifdef USE_TEXT_SENSOR
   virtual bool on_text_sensor(text_sensor::TextSensor *text_sensor) = 0;
 #endif
@@ -78,6 +81,9 @@ class ComponentIterator {
 #ifdef USE_SWITCH
     SWITCH,
 #endif
+#ifdef USE_BUTTON
+    BUTTON,
+#endif
 #ifdef USE_TEXT_SENSOR
     TEXT_SENSOR,
 #endif

esphome/components/button/__init__.py

@@ -0,0 +1,104 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome import automation
+from esphome.automation import maybe_simple_id
+from esphome.components import mqtt
+from esphome.const import (
+    CONF_ENTITY_CATEGORY,
+    CONF_ICON,
+    CONF_ID,
+    CONF_ON_PRESS,
+    CONF_TRIGGER_ID,
+    CONF_MQTT_ID,
+)
+from esphome.core import CORE, coroutine_with_priority
+from esphome.cpp_helpers import setup_entity
+
+CODEOWNERS = ["@esphome/core"]
+IS_PLATFORM_COMPONENT = True
+
+button_ns = cg.esphome_ns.namespace("button")
+Button = button_ns.class_("Button", cg.EntityBase)
+ButtonPtr = Button.operator("ptr")
+
+PressAction = button_ns.class_("PressAction", automation.Action)
+
+ButtonPressTrigger = button_ns.class_(
+    "ButtonPressTrigger", automation.Trigger.template()
+)
+
+
+BUTTON_SCHEMA = cv.ENTITY_BASE_SCHEMA.extend(cv.MQTT_COMMAND_COMPONENT_SCHEMA).extend(
+    {
+        cv.OnlyWith(CONF_MQTT_ID, "mqtt"): cv.declare_id(mqtt.MQTTButtonComponent),
+        cv.Optional(CONF_ON_PRESS): automation.validate_automation(
+            {
+                cv.GenerateID(CONF_TRIGGER_ID): cv.declare_id(ButtonPressTrigger),
+            }
+        ),
+    }
+)
+
+_UNDEF = object()
+
+
+def button_schema(
+    icon: str = _UNDEF,
+    entity_category: str = _UNDEF,
+) -> cv.Schema:
+    schema = BUTTON_SCHEMA
+    if icon is not _UNDEF:
+        schema = schema.extend({cv.Optional(CONF_ICON, default=icon): cv.icon})
+    if entity_category is not _UNDEF:
+        schema = schema.extend(
+            {
+                cv.Optional(
+                    CONF_ENTITY_CATEGORY, default=entity_category
+                ): cv.entity_category
+            }
+        )
+    return schema
+
+
+async def setup_button_core_(var, config):
+    await setup_entity(var, config)
+
+    for conf in config.get(CONF_ON_PRESS, []):
+        trigger = cg.new_Pvariable(conf[CONF_TRIGGER_ID], var)
+        await automation.build_automation(trigger, [], conf)
+
+    if CONF_MQTT_ID in config:
+        mqtt_ = cg.new_Pvariable(config[CONF_MQTT_ID], var)
+        await mqtt.register_mqtt_component(mqtt_, config)
+
+
+async def register_button(var, config):
+    if not CORE.has_id(config[CONF_ID]):
+        var = cg.Pvariable(config[CONF_ID], var)
+    cg.add(cg.App.register_button(var))
+    await setup_button_core_(var, config)
+
+
+async def new_button(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await register_button(var, config)
+    return var
+
+
+BUTTON_PRESS_SCHEMA = maybe_simple_id(
+    {
+        cv.Required(CONF_ID): cv.use_id(Button),
+    }
+)
+
+
+@automation.register_action("button.press", PressAction, BUTTON_PRESS_SCHEMA)
+async def button_press_to_code(config, action_id, template_arg, args):
+    paren = await cg.get_variable(config[CONF_ID])
+    return cg.new_Pvariable(action_id, template_arg, paren)
+
+
+@coroutine_with_priority(100.0)
+async def to_code(config):
+    cg.add_global(button_ns.using)
+    cg.add_define("USE_BUTTON")

esphome/components/button/automation.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include "esphome/components/button/button.h"
+#include "esphome/core/automation.h"
+#include "esphome/core/component.h"
+
+namespace esphome {
+namespace button {
+
+template<typename... Ts> class PressAction : public Action<Ts...> {
+ public:
+  explicit PressAction(Button *button) : button_(button) {}
+
+  void play(Ts... x) override { this->button_->press(); }
+
+ protected:
+  Button *button_;
+};
+
+class ButtonPressTrigger : public Trigger<> {
+ public:
+  ButtonPressTrigger(Button *button) {
+    button->add_on_press_callback([this]() { this->trigger(); });
+  }
+};
+
+}  // namespace button
+}  // namespace esphome

esphome/components/button/button.cpp

@@ -0,0 +1,21 @@
+#include "button.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace button {
+
+static const char *const TAG = "button";
+
+Button::Button(const std::string &name) : EntityBase(name) {}
+Button::Button() : Button("") {}
+
+void Button::press() {
+  ESP_LOGD(TAG, "'%s' Pressed.", this->get_name().c_str());
+  this->press_action();
+  this->press_callback_.call();
+}
+void Button::add_on_press_callback(std::function<void()> &&callback) { this->press_callback_.add(std::move(callback)); }
+uint32_t Button::hash_base() { return 1495763804UL; }
+
+}  // namespace button
+}  // namespace esphome

esphome/components/button/button.h

@@ -0,0 +1,50 @@
+#pragma once
+
+#include "esphome/core/component.h"
+#include "esphome/core/entity_base.h"
+#include "esphome/core/helpers.h"
+
+namespace esphome {
+namespace button {
+
+#define LOG_BUTTON(prefix, type, obj) \
+  if ((obj) != nullptr) { \
+    ESP_LOGCONFIG(TAG, "%s%s '%s'", prefix, LOG_STR_LITERAL(type), (obj)->get_name().c_str()); \
+    if (!(obj)->get_icon().empty()) { \
+      ESP_LOGCONFIG(TAG, "%s  Icon: '%s'", prefix, (obj)->get_icon().c_str()); \
+    } \
+  }
+
+/** Base class for all buttons.
+ *
+ * A button is just a momentary switch that does not have a state, only a trigger.
+ */
+class Button : public EntityBase {
+ public:
+  explicit Button();
+  explicit Button(const std::string &name);
+
+  /** Press this button. This is called by the front-end.
+   *
+   * For implementing buttons, please override press_action.
+   */
+  void press();
+
+  /** Set callback for state changes.
+   *
+   * @param callback The void() callback.
+   */
+  void add_on_press_callback(std::function<void()> &&callback);
+
+ protected:
+  /** You should implement this virtual method if you want to create your own button.
+   */
+  virtual void press_action(){};
+
+  uint32_t hash_base() override;
+
+  CallbackManager<void()> press_callback_{};
+};
+
+}  // namespace button
+}  // namespace esphome

esphome/components/mqtt/__init__.py

@@ -95,6 +95,7 @@ MQTTSwitchComponent = mqtt_ns.class_("MQTTSwitchComponent", MQTTComponent)
 MQTTTextSensor = mqtt_ns.class_("MQTTTextSensor", MQTTComponent)
 MQTTNumberComponent = mqtt_ns.class_("MQTTNumberComponent", MQTTComponent)
 MQTTSelectComponent = mqtt_ns.class_("MQTTSelectComponent", MQTTComponent)
+MQTTButtonComponent = mqtt_ns.class_("MQTTButtonComponent", MQTTComponent)
 
 MQTTDiscoveryUniqueIdGenerator = mqtt_ns.enum("MQTTDiscoveryUniqueIdGenerator")
 MQTT_DISCOVERY_UNIQUE_ID_GENERATOR_OPTIONS = {

esphome/components/mqtt/mqtt_button.cpp

@@ -0,0 +1,40 @@
+#include "mqtt_button.h"
+#include "esphome/core/log.h"
+
+#include "mqtt_const.h"
+
+#ifdef USE_MQTT
+#ifdef USE_BUTTON
+
+namespace esphome {
+namespace mqtt {
+
+static const char *const TAG = "mqtt.button";
+
+using namespace esphome::button;
+
+MQTTButtonComponent::MQTTButtonComponent(button::Button *button) : MQTTComponent(), button_(button) {}
+
+void MQTTButtonComponent::setup() {
+  this->subscribe(this->get_command_topic_(), [this](const std::string &topic, const std::string &payload) {
+    if (payload == "press") {
+      this->button_->press();
+    } else {
+      ESP_LOGW(TAG, "'%s': Received unknown status payload: %s", this->friendly_name().c_str(), payload.c_str());
+      this->status_momentary_warning("state", 5000);
+    }
+  });
+}
+void MQTTButtonComponent::dump_config() {
+  ESP_LOGCONFIG(TAG, "MQTT Button '%s': ", this->button_->get_name().c_str());
+  LOG_MQTT_COMPONENT(true, true);
+}
+
+std::string MQTTButtonComponent::component_type() const { return "button"; }
+const EntityBase *MQTTButtonComponent::get_entity() const { return this->button_; }
+
+}  // namespace mqtt
+}  // namespace esphome
+
+#endif
+#endif  // USE_MQTT

esphome/components/mqtt/mqtt_button.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include "esphome/core/defines.h"
+
+#ifdef USE_MQTT
+#ifdef USE_BUTTON
+
+#include "esphome/components/button/button.h"
+#include "mqtt_component.h"
+
+namespace esphome {
+namespace mqtt {
+
+class MQTTButtonComponent : public mqtt::MQTTComponent {
+ public:
+  explicit MQTTButtonComponent(button::Button *button);
+
+  // ========== INTERNAL METHODS ==========
+  // (In most use cases you won't need these)
+  void setup() override;
+  void dump_config() override;
+
+  /// Buttons do not send a state so just return true.
+  bool send_initial_state() override { return true; }
+
+  void send_discovery(JsonObject &root, mqtt::SendDiscoveryConfig &config) override {}
+
+ protected:
+  /// "button" component type.
+  std::string component_type() const override;
+  const EntityBase *get_entity() const override;
+
+  button::Button *button_;
+};
+
+}  // namespace mqtt
+}  // namespace esphome
+
+#endif
+#endif  // USE_MQTT

esphome/components/restart/button/__init__.py

@@ -0,0 +1,23 @@
+import esphome.codegen as cg
+import esphome.config_validation as cv
+from esphome.components import button
+from esphome.const import (
+    CONF_ID,
+    ENTITY_CATEGORY_CONFIG,
+    ICON_RESTART,
+)
+
+restart_ns = cg.esphome_ns.namespace("restart")
+RestartButton = restart_ns.class_("RestartButton", button.Button, cg.Component)
+
+CONFIG_SCHEMA = (
+    button.button_schema(icon=ICON_RESTART, entity_category=ENTITY_CATEGORY_CONFIG)
+    .extend({cv.GenerateID(): cv.declare_id(RestartButton)})
+    .extend(cv.COMPONENT_SCHEMA)
+)
+
+
+async def to_code(config):
+    var = cg.new_Pvariable(config[CONF_ID])
+    await cg.register_component(var, config)
+    await button.register_button(var, config)

esphome/components/restart/button/restart_button.cpp

@@ -0,0 +1,20 @@
+#include "restart_button.h"
+#include "esphome/core/application.h"
+#include "esphome/core/hal.h"
+#include "esphome/core/log.h"
+
+namespace esphome {
+namespace restart {
+
+static const char *const TAG = "restart.button";
+
+void RestartButton::press_action() {
+  ESP_LOGI(TAG, "Restarting device...");
+  // Let MQTT settle a bit
+  delay(100);  // NOLINT
+  App.safe_reboot();
+}
+void RestartButton::dump_config() { LOG_BUTTON("", "Restart Button", this); }
+
+}  // namespace restart
+}  // namespace esphome

esphome/components/restart/button/restart_button.h

@@ -0,0 +1,18 @@
+#pragma once
+
+#include "esphome/components/button/button.h"
+#include "esphome/core/component.h"
+
+namespace esphome {
+namespace restart {
+
+class RestartButton : public button::Button, public Component {
+ public:
+  void dump_config() override;
+
+ protected:
+  void press_action() override;
+};
+
+}  // namespace restart
+}  // namespace esphome

esphome/components/template/button/__init__.py

@@ -0,0 +1,13 @@
+import esphome.config_validation as cv
+from esphome.components import button
+
+
+CONFIG_SCHEMA = button.BUTTON_SCHEMA.extend(
+    {
+        cv.GenerateID(): cv.declare_id(button.Button),
+    }
+).extend(cv.COMPONENT_SCHEMA)
+
+
+async def to_code(config):
+    await button.new_button(config)

esphome/components/web_server/web_server.cpp

@@ -198,6 +198,11 @@ void WebServer::handle_index_request(AsyncWebServerRequest *request) {
       write_row(stream, obj, "switch", "<button>Toggle</button>");
 #endif
 
+#ifdef USE_BUTTON
+  for (auto *obj : App.get_buttons())
+    write_row(stream, obj, "button", "<button>Press</button>");
+#endif
+
 #ifdef USE_BINARY_SENSOR
   for (auto *obj : App.get_binary_sensors())
     if (this->include_internal_ || !obj->is_internal())
@@ -382,6 +387,26 @@ void WebServer::handle_switch_request(AsyncWebServerRequest *request, const UrlM
 }
 #endif
 
+#ifdef USE_BUTTON
+void WebServer::handle_button_request(AsyncWebServerRequest *request, const UrlMatch &match) {
+  for (button::Button *obj : App.get_buttons()) {
+    if (obj->is_internal())
+      continue;
+    if (obj->get_object_id() != match.id)
+      continue;
+
+    if (request->method() == HTTP_POST && match.method == "press") {
+      this->defer([obj]() { obj->press(); });
+      request->send(200);
+    } else {
+      request->send(404);
+    }
+    return;
+  }
+  request->send(404);
+}
+#endif
+
 #ifdef USE_BINARY_SENSOR
 void WebServer::on_binary_sensor_update(binary_sensor::BinarySensor *obj, bool state) {
   this->events_.send(this->binary_sensor_json(obj, state).c_str(), "state");
@@ -715,6 +740,11 @@ bool WebServer::canHandle(AsyncWebServerRequest *request) {
     return true;
 #endif
 
+#ifdef USE_BUTTON
+  if (request->method() == HTTP_POST && match.domain == "button")
+    return true;
+#endif
+
 #ifdef USE_BINARY_SENSOR
   if (request->method() == HTTP_GET && match.domain == "binary_sensor")
     return true;
@@ -787,6 +817,13 @@ void WebServer::handleRequest(AsyncWebServerRequest *request) {
   }
 #endif
 
+#ifdef USE_BUTTON
+  if (match.domain == "button") {
+    this->handle_button_request(request, match);
+    return;
+  }
+#endif
+
 #ifdef USE_BINARY_SENSOR
   if (match.domain == "binary_sensor") {
     this->handle_binary_sensor_request(request, match);

esphome/components/web_server/web_server.h

@@ -112,6 +112,11 @@ class WebServer : public Controller, public Component, public AsyncWebHandler {
   std::string switch_json(switch_::Switch *obj, bool value);
 #endif
 
+#ifdef USE_BUTTON
+  /// Handle a button request under '/button/<id>/press'.
+  void handle_button_request(AsyncWebServerRequest *request, const UrlMatch &match);
+#endif
+
 #ifdef USE_BINARY_SENSOR
   void on_binary_sensor_update(binary_sensor::BinarySensor *obj, bool state) override;
 

esphome/core/application.h

@@ -17,6 +17,9 @@
 #ifdef USE_SWITCH
 #include "esphome/components/switch/switch.h"
 #endif
+#ifdef USE_BUTTON
+#include "esphome/components/button/button.h"
+#endif
 #ifdef USE_TEXT_SENSOR
 #include "esphome/components/text_sensor/text_sensor.h"
 #endif
@@ -67,6 +70,10 @@ class Application {
   void register_switch(switch_::Switch *a_switch) { this->switches_.push_back(a_switch); }
 #endif
 
+#ifdef USE_BUTTON
+  void register_button(button::Button *button) { this->buttons_.push_back(button); }
+#endif
+
 #ifdef USE_TEXT_SENSOR
   void register_text_sensor(text_sensor::TextSensor *sensor) { this->text_sensors_.push_back(sensor); }
 #endif
@@ -167,6 +174,15 @@ class Application {
     return nullptr;
   }
 #endif
+#ifdef USE_BUTTON
+  const std::vector<button::Button *> &get_buttons() { return this->buttons_; }
+  button::Button *get_button_by_key(uint32_t key, bool include_internal = false) {
+    for (auto *obj : this->buttons_)
+      if (obj->get_object_id_hash() == key && (include_internal || !obj->is_internal()))
+        return obj;
+    return nullptr;
+  }
+#endif
 #ifdef USE_SENSOR
   const std::vector<sensor::Sensor *> &get_sensors() { return this->sensors_; }
   sensor::Sensor *get_sensor_by_key(uint32_t key, bool include_internal = false) {
@@ -260,6 +276,9 @@ class Application {
 #ifdef USE_SWITCH
   std::vector<switch_::Switch *> switches_{};
 #endif
+#ifdef USE_BUTTON
+  std::vector<button::Button *> buttons_{};
+#endif
 #ifdef USE_SENSOR
   std::vector<sensor::Sensor *> sensors_{};
 #endif

esphome/core/controller.h

@@ -22,6 +22,9 @@
 #ifdef USE_SWITCH
 #include "esphome/components/switch/switch.h"
 #endif
+#ifdef USE_BUTTON
+#include "esphome/components/button/button.h"
+#endif
 #ifdef USE_CLIMATE
 #include "esphome/components/climate/climate.h"
 #endif

esphome/core/defines.h

@@ -16,6 +16,7 @@
 #define USE_API_NOISE
 #define USE_API_PLAINTEXT
 #define USE_BINARY_SENSOR
+#define USE_BUTTON
 #define USE_CLIMATE
 #define USE_COVER
 #define USE_DEEP_SLEEP

script/ci-custom.py

@@ -603,6 +603,7 @@ def lint_inclusive_language(fname, match):
         "esphome/components/switch/switch.h",
         "esphome/components/text_sensor/text_sensor.h",
         "esphome/components/climate/climate.h",
+        "esphome/components/button/button.h",
         "esphome/core/component.h",
         "esphome/core/gpio.h",
         "esphome/core/log.h",

tests/test4.yaml

@@ -520,3 +520,7 @@ xpt2046:
             id(touchscreen).y_raw,
             id(touchscreen).z_raw
             );
+
+button:
+  - platform: restart
+    name: Restart Button