Set form attribute on inputs when form is given an id #610

defmodule MyWeb.FormsComponent do
  use Surface.Component
  alias Surface.Components.Context
  alias Surface.Components.Form.{Field, Label, TextInput}

  def render(assigns) do
    ~F"""
    <Context get={form: form}>
      <Field name={:thing}>
        <Label text="Thing" form={form} />
        <TextInput form={form} opts={form: form.id} />
      </Field>
    </Context>
    """
  end
end

defmodule MyWeb.FormsComponentNamedspaceContext do
  use Surface.Component
  alias Surface.Components.Context
  alias Surface.Components.Form.{Field, Label, TextInput}

  def render(assigns) do
    ~F"""
    <Context get={Surface.Components.Form, form: form}>
      <Field name={:thing}>
        <Label text="Thing" />
        <TextInput opts={form: form.id} />
      </Field>
    </Context>
    """
  end
end

defmodule MyWeb.IdealFormsComponent do
  use Surface.Component
  alias Surface.Components.Context
  alias Surface.Components.Form.{Field, Label, TextInput}

  def render(assigns) do
    ~F"""
    <Field name={:thing}>
      <Label text="Thing" />
      <TextInput />
    </Field>
    """
  end
end

defmodule MyWeb.FormsLive do
  use MyWeb, :surface_live_view
  alias MyWeb.FormsComponent
  alias MyWeb.FormsComponentNamedspaceContext
  alias Surface.Components.Context

  @impl true
  def mount(_params, _session, socket) do
    {:ok,
     assign(socket,
       thing1: changeset(%{thing: "thing1"}),
       thing2: changeset(%{thing: "thing2"})
     )}
  end

  defp changeset(data \\ %{}, params) do
    types = %{thing: :string}
    Ecto.Changeset.cast({data, types}, params, Map.keys(types))
  end

  @impl true
  def render(assigns) do
    ~F"""
    <main>
      {form1 =
        form_for(@thing1, "#",
          as: :thing1,
          id: "thing1form",
          phx_change: "change1",
          autocomplete: "off"
        )}
      <#Raw></form></#Raw>

      {form2 =
        form_for(@thing2, "#",
          as: :thing2,
          id: "thing2form",
          phx_change: "change2",
          autocomplete: "off"
        )}
      <#Raw></form></#Raw>

      {!--
      <Context put={Surface.Components.Form, form: form1}>
        <IdealFormsComponent />
      </Context>
      --}

      <Context put={Surface.Components.Form, form: form1}>
        <FormsComponentNamedspaceContext />
      </Context>

      <Context put={form: form2}>
        <FormsComponent />
      </Context>
    </main>
    """
  end

  @impl true
  def handle_event(event, params, socket) do
    IO.inspect([event, params], label: "forms live")
    {:noreply, socket}
  end
end