constant_sensor.h

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#ifndef SENSESP_SENSORS_CONSTANT_SENSOR_H_
#define SENSESP_SENSORS_CONSTANT_SENSOR_H_
 
#include "Arduino.h"
#include "sensesp/ui/config_item.h"
#include "sensesp/sensors/sensor.h"
#include "sensesp_base_app.h"
 
namespace sensesp {
 
template <class T>
class ConstantSensor : public Sensor<T> {
 public:
  ConstantSensor(T value, int send_interval = 30, String config_path = "")
      : Sensor<T>(config_path), value_{value}, send_interval_{send_interval} {
    this->load();
 
    // Emit the initial value once to set the output
    event_loop()->onDelay(0, [this]() { this->emit(value_); });
    // Then, emit the value at the specified interval
    event_loop()->onRepeat(send_interval_ * 1000,
                           [this]() { this->emit(value_); });
  }
 
  void set(T value) { value_ = value; }
 
  virtual bool to_json(JsonObject& doc) override {
    doc["value"] = value_;
    return true;
  }
  virtual bool from_json(const JsonObject& config) override {
    // Neither of the configuration parameters are mandatory
    if (config["value"].is<T>()) {
      value_ = config["value"].as<T>();
    }
    return true;
  }
 
 protected:
  void update() { this->emit(value_); }
 
  T value_;
  int send_interval_;  // seconds
};
 
template <typename T>
const String ConfigSchemaSensorType(const T& obj) {
  return "";
}
template <>
const String ConfigSchemaSensorType<int>(const int& obj) {
  return "integer";
}
template <>
const String ConfigSchemaSensorType<float>(const float& obj) {
  return "number";
}
template <>
const String ConfigSchemaSensorType<String>(const String& obj) {
  return "string";
}
template <>
const String ConfigSchemaSensorType<bool>(const bool& obj) {
  return "boolean";
}
 
template <typename T>
const String ConfigSchema(const ConstantSensor<T>& obj) {
  String schema = R"###({"type":"object","properties":{"value":{"title":"Constant Value","type":"%TYPE%","description":"Constant value"}}    })###";
  ;
  schema.replace("%TYPE%", ConfigSchemaSensorType(obj));
  return schema.c_str();
}
 
// ..........................................
//  constant value sensors
// ..........................................
 
typedef ConstantSensor<float> FloatConstantSensor;
typedef ConstantSensor<int> IntConstantSensor;
typedef ConstantSensor<bool> BoolConstantSensor;
typedef ConstantSensor<String> StringConstantSensor;
 
}  // namespace sensesp
 
#endif