Option update callback

[aakashjhawar]

Define a callback to send updated options to the LiveView or Component where LiveSelect component is initialized.

[maxmarcon]

Hi! What is the use-case for this change? When an option is selected/removed, a change event is triggered on the form, right?

[aakashjhawar]

Hi, @maxmarcon!

Yes, when an option is selected / removed, an event is triggered to the form.

To get notified of any option selected / removed, we need pass on_option_update attribute and handle its update event in the form.

When initializing live_select from a LiveView, we can use:

<.live_select 
  field={@form[:city_search]} 
  on_option_update={fn option -> send(self, option) end}
/>

and to handle its event:

def handle_info(%{option_click: option}, socket) do
  ...
  {:noreply, socket}
end

def handle_info(%{option_remove: option}, socket) do
  ...
  {:noreply, socket}
end

If initializing it inside another component, one may write:

<.live_select
  field={@form[:city_search]}
  phx-target={@myself}
  on_option_update={fn option -> send_update(@myself, option) end}
 />

and to handle its event:

def update(%{option_click: option}, socket) do
  ...
  {:ok, socket}
end

def update(%{option_remove: option}, socket) do
   ...
  {:ok, socket}
end

This can be useful in cases when someone wants to do certain actions while the user is selecting options, or to track user activity.