No validation error when submitting a required select component with an empty option

[rbarreca]

It's probably just user error, but I can't figure out how to make a required select component with an empty option. It doesn't trigger any Polaris validation, rather just gets to the Rails controller and errors out with undefined method map' for nil:NilClass`.

I've tried adding [''] or [['', '']] or [['', nil]] to @options_from_controller, but none of them do the trick. What am I doing wrong?

<%= polaris_select(name: 'vendor_product_setting[foo_id]', 
              label: "Infoplus vendor",
              options: @options_from_controller, 
              required: true, selected: @vendor_product_setting.foo_id) %>

The example for required doesn't have an empty option which makes it not useful.

[k0va1]

Hi @rbarreca! Basically, polaris_select uses Rails select under the hood, so you can pass either input_options: { include_blank: true } or input_options: { prompt: "Select..." } to achieve the desired behavior

[rbarreca]

Thanks @k0va1 that sent me in the right direction, although it's select_options: { include_blank: true }. I opened #332 to improve the example (although I'm not sure if there is another spot I need to update for the docs).

Now I have a blank, but I'm expecting there to be a validation error message when submitting since it's required, but I don't have one. Do you have any advice?

View

<%= polaris_page(
  title: @vendor_product_setting.persisted? ? "Edit vendor product setting" : "Add vendor product setting",
  back_url: vendor_product_settings_path
) do %>
  <%= polaris_card do %>
    <%= form_with(model: @vendor_product_setting, builder: Polaris::FormBuilder) do |form| %>
      <%= polaris_form_layout do |form_layout| %>
        <% form_layout.with_item do %>
          <%= form.polaris_select(:infoplus_vendor_id, 
              label: "Infoplus vendor",
              options: @infoplus_vendor_options, 
              required: true, 
              select_options: { include_blank: true }
            ) %>
        <% end %>
        <% form_layout.with_item do %>
          <%= form.polaris_text_field(:sku, label: "SKU", 
                help_text: "Leave empty to set the default incoming percentage for this vendor.") %>
        <% end %>
        <% form_layout.with_item do %>
          <%= form.polaris_text_field(:incoming_percent, label: "Percent incoming to list", 
                type: :number, min: 0, max: 100) %>
        <% end %>
        <% form_layout.with_item do %>
          <%= polaris_button(submit: true, primary: true) { "Submit" } %>
        <% end %>
      <% end %>
    <% end %>
  <% end %>
<% end %>

Controller

class VendorProductSettingsController < AuthenticatedController
  before_action :set_infoplus_vendor_options, only: [:edit, :new, :create, :update]

  def index
    @vendor_product_settings = VendorProductSetting.all
  end

  def edit
    @vendor_product_setting = VendorProductSetting.find(params[:id])
  end

  def new
    @vendor_product_setting = VendorProductSetting.new
  end

  def create
    @vendor_product_setting = VendorProductSetting.new(vendor_product_setting_params)

    if @vendor_product_setting.save
      redirect_to vendor_product_settings_path
    else
      render :new, status: :unprocessable_entity
    end
  end

  def update
    @vendor_product_setting = VendorProductSetting.find(params[:id])

    if @vendor_product_setting.update(vendor_product_setting_params)
      turbo_redirect_to vendor_product_settings_path, notice: 'Vendor product setting was successfully updated.'
    else
      render :edit, status: :unprocessable_entity
    end
  end

  private

  def vendor_product_setting_params
    params.require(:vendor_product_setting).permit(:infoplus_vendor_id, :sku, :incoming_percent)
  end

  def set_infoplus_vendor_options
    @infoplus_vendor_options = InfoplusVendor.all.map do |v|
      [v.name, v.id]
    end
  end
end