Onchange on number type input field

What’s the reason for using :erlang.binary_to_float/1 instead of Float.parse/1?

iex> :erlang.binary_to_float("1")
** (ArgumentError) errors were found at the given arguments:

  * 1st argument: not a textual representation of a float

    :erlang.binary_to_float("1")
    iex:2: (file)
iex> {num, _} = Float.parse("1")
{1.0, ""}
iex> num
1.0
iex> {num, _} = Float.parse("1.")
{1.0, "."}

You can match the result in a with or case block and only modify the socket on success.

def handle_event("change", %{"quantity" => quantity}, socket) do
  socket =
    case Float.parse(quantity) do
      {float, _remainder_of_binary} -> assign(socket, :quantity, float)
      :error -> socket
    end

  {:noreply, socket}
end

Hey! Sorry for replying so late. Thank you, this worked well. I don’t know why, but for some reason i used String.to_float/1.

No worries, I’ve made the same mistake before. I was just going off the error message but see now that String.to_float/1 inlines the :erlang function.