Add attribute name to callback parameters for CustomAPIDevice::subscribe_homeassistant_state

[olicooper]

Describe the problem you have/What new integration you would like

I am finding that I am having to add a wrapper function for my state subscription callbacks because the subscribe_homeassistant_state callback doesn't return the attribute name as a parameter.

I would like the function changing (or a new one adding) from this:
e.g. this->subscribe_homeassistant_state([this](std::string entity_id, std::string state) { }, "light.my_light", "supported_modes");

void APIConnection::on_home_assistant_state_response(const HomeAssistantStateResponse &msg) {
  for (auto &it : this->parent_->get_state_subs()) {
    if (it.entity_id == msg.entity_id && it.attribute.value() == msg.attribute) {
      it.callback(msg.state);
    }
  }
}

To something like this
e.g. this->subscribe_homeassistant_state([this](std::string entity_id, std::string attribute, std::string state, std::string attribute) { }, "light.my_light", "supported_modes");

void APIConnection::on_home_assistant_state_response(const HomeAssistantStateResponse &msg) {
  for (auto &it : this->parent_->get_state_subs()) {
    if (it.entity_id == msg.entity_id && it.attribute.value() == msg.attribute) {
      it.callback(msg.state, msg.attribute);
    }
  }
}

Please describe your use case for this integration and alternatives you've tried:

Currently, I am creating lots of wrapper functions (seen here) to give me the functionality but I have a lot more to add and it is getting messy now.

Additional context

[ssieb]

Why do you need to make a custom component like this? What are you trying to do?

[olicooper]

The project can be found here which will explain the idea better: esphome-nspanel-lovelace-native

Essentially my project is an interface between a screen and Home Assistant. To build the commands for the screen I need to subscribe to state/attribute updates from HA entities that don't exist within the device, and because esphome 'components' represent internal device features which are exposed to HA, they don't work for what I need - which is a simple way to ask HA what the current state is of arbitrary entities.

There are many external entities and attributes that I need to monitor and creating a new function for every attribute type is not feasible. If the callback could include the attribute name I would then be able to remove all the additional functions mentioned here