Bootstrap v5 bootstrap_form Floating Labels support

bootstrap_form.rb

# config/initializers/bootstrap_form.rb
module BootstrapForm
  module FormGroup
    def form_group_classes(options)
      classes = ['mb-3', options[:class].try(:split)].flatten.compact
      classes << 'form-label-group' if options[:layout] == :floating
      classes << 'row' if horizontal_group_with_gutters?(options[:layout], classes)
      classes << 'col-auto g-3' if field_inline_override?(options[:layout])
      classes << feedback_class if options[:icon]
      classes
    end

    def form_group_content(label, help_text, options, &block)
      if group_layout_horizontal?(options[:layout])
        concat(label).concat(tag.div(capture(&block) + help_text, class: form_group_control_class(options)))
      elsif options[:layout] == :floating
        concat(capture(&block))
        concat(label)
        concat(help_text) if help_text
      else
        concat(label)
        concat(capture(&block))
        concat(help_text) if help_text
      end
    end
  end
end

Steps:

1. Create the file above
2. Make sure you use the extra CSS needed like in the v5 docs floating labels example.
3. In your form, set the bootstrap_form layout to :floating:

<%= bootstrap_form_for(@user, layout: :floating) do |f| %>
  <%= f.email_field :email, autofocus: true, autocomplete: "email", placeholder: "Email" %>
  <%= f.password_field :password, autocomplete: "current-password", placeholder: "Password" %>
  <%= f.primary "Log in" %>
<% end %>