Dynamic Entity

[kevinschweikert]

An advanced usage of Homex having support for defining a type of device and associated entities and then name and provide identifiers for multiple of those. Start Homex with custom config and derive device and entity definitions at runtime

Something like Homex.MultiManager.add_entity({MyApp.Camera, device: "camera-1", video_device: "/dev/video0"})

Homex.add_device("camera-1"
  [
    {MyApp.CameraThumbnails,
      opt_1: "foo"
    },
    {MyApp.CameraIntruderDetection,
      model: "bla.onnx"
    }
  ]
)

[kevinschweikert]

I've worked on a possible public API:

Homex.start(MyApp.CameraThumbnails, name: "my_thumbnails", device: "camera_1", camera_name: "Hikvision X100", fps: 25)

This would mean, we shift the configuraton from compile time to runtime or at least merge runtime opts with static compile time opts. In an entity it could look like this:

defmodule MyApp.SomeEntity do
	use Homex.Entity.Camera

	def handle_setup(opts, entity) do
		entity
		|> assign(name: entity.name)
		|> assign(manufacturer: entity.device.manufacturer)
		|> assign(camera_name: opts[:camera_name])
	end
end

This let's us define a static behaviour for an entity and use this entity multiple times. Maybe like this:

Homex.start_many([
    {MyApp.CameraThumbnails, name: "my_house_thumbnails", device: "camera_1", host: "127.0.0.1"},
    {MyApp.CameraThumbnails, name: "my_garden_thumbnails", device: "camera_2", host: "example.com"}
])

For entities which need to receive signals we can create an API with the name as the identifier:

Homex.Entity.Button.press("my_button")
Homex.Entity.HVAC.set_temperature("my_hvac", 23.6)

To send normal OTP messages we could either give the user the process PID or wrap the send/call/cast functions like this:

Homex.send("my_entity", :foo)
Homex.call("my_entity", :foo)
Homex.cast("my_entity", :foo)

This would go hand in hand with the multiple device feature which have to be created beforehand. This could look like this.

Homex.add_device("camera_1", manufacturer: "foo", model: "bar")

On startup we would create a default device with the hostname as the identifier as use that, whenever no device is specified on entity start