Provided Sensor

A provided sensor can represent any integer, double or String state of a bean as an entity in Home Assistant, making it available for use in UI components or automations. To create a provided sensor, declare a field of type ProvidedSensor in your bean and annotate it with @Provided. SmartBeans will then automatically create the sensor in Home Assistant, generate the corresponding Java object to control it, and inject this object into the annotated field. You can update the sensor's state using the setState() method, which comes in three versions for integer, double and String.

A provided sensor can represent any int, double, or String state of a bean as an entity in Home Assistant, making it available for use in UI components or automations. To create a provided sensor, declare a field of type ProvidedSensor in your bean and annotate it with @Provided. SmartBeans will then automatically create the sensor in Home Assistant, generate the corresponding Java object to control it, and inject this object into the annotated field. You can update the sensor's state using the setState() method, which is available in three variants for int, double, and String types.

@SmartBeanDef(beanDevice = @BeanDevice)
public class ASampleBean implements SmartBean {

  @Provided(entityId = "sensor.a_sample_sensor")
  private ProvidedSensor providedSensor;

  public void updateSensor() {
    providedSensor.setState("foo");
  }
}

note

The @SmartBeanDef(beanDevice = @BeanDevice) annotation is required on your bean to create the corresponding bean device in Home Assistant. Without this annotation, no bean device will be created, and therefore no provided entities can be created, since they cannot be associated with a device.

Entity Configuration

The @Provided annotation can be used to configure the provided sensor in detail. It supports the following attributes:

Attribute	Description
entityId	Required. The entity_id of the entity created in Home Assistant. If an entity with this ID already exists, Home Assistant appends _2 to it.
id	The internal ID of the entity. This ID must be unique within the scope of the bean device. If not specified, the field name is used.
friendlyName	The friendly name of the entity displayed in Home Assistant.
icon	The icon shown in Home Assistant for this entity. If no icon is specified, it is derived from the device class.
deviceClass	The device class of the entity in Home Assistant.
unitOfMeasurement	The unit of measurement used in Home Assistant. If not specified, it is derived from the device class.
stateClass	The state class of the entity in Home Assistant.
options	If set, the sensor can only take values from this array.

The entity ID, friendly name, and icon are only initial values set when the entity is created. They can later be modified by the user through the Home Assistant interface.

Setting State and Attributes

As mentioned above, the state of the sensor can be updated using the setState() method. In addition, you can attach custom attributes to the sensor. The ProvidedSensor interface offers several setAttribute() methods for different data types, such as Integer, Boolean, or String.

@SmartBeanDef(beanDevice = @BeanDevice)
public class DiskSpaceBean implements SmartBean {

  @Provided(
      entityId = "sensor.free_disk_space",
      friendlyName = "Free Disk Space",
      icon = "mdi:harddisk",
      deviceClass = "data_size",
      unitOfMeasurement = "GB"
  )
  private ProvidedSensor freeDiskSpace;

  public void updateSensor() {
    long freeSpace = getFreeDiskSpace();
    freeDiskSpace.setState((double)freeSpace / 1024d / 1024d / 1024d);
    freeDiskSpace.setAttribute("total_size", getTotalDiskSize());
  }
}

Keep in mind that the entity is not updated automatically when it is created or when the bean is deployed. If you want the sensor to update immediately upon creation, you need to override the bean's init() method or use the readState() method, which is called when the persistent bean state is loaded.

Create Entity Programmatically

In addition to the annotation-based approach, you can programmatically create a binary sensor using the provideSensor() method of the SmartBeans API. This approach is useful when the entity's attributes are generated dynamically through business logic and cannot be determined at compile time.

The method accepts three arguments: the first is the internal ID, which must be unique within the scope of the bean; the second is the entity ID used in Home Assistant; and the third is an optional builder for setting all other attributes.

@SmartBeanDef(beanDevice = @BeanDevice)
public class ASampleBean implements SmartBean {

  private ProvidedSensor freeDiskSpace;

  @Override
  public void init(SmartBeans sb) {
    freeDiskSpace = sb.provideSensor("my_sensor", "sensor.free_disk_space", def -> def
        .setFriendlyName("Free Disk Space")
        .setIcon("mdi:harddisk")
        .setDeviceClass("data_size")
        .setUnitOfMeasurement("GB")
    );
  }
}