feat: better loading

examples/dynamic/dynamic-country/main.go

@@ -44,6 +44,24 @@ func main() {
 					time.Sleep(1000 * time.Millisecond)
 					return huh.NewOptions(s...)
 				}, &country /* only this function when `country` changes */),
+			huh.NewSelect[string]().
+				Height(8).
+				TitleFunc(func() string {
+					switch country {
+					case "United States":
+						return "State"
+					case "Canada":
+						return "Province"
+					default:
+						return "Territory"
+					}
+				}, &country).
+				OptionsFunc(func() []huh.Option[string] {
+					s := states[country]
+					// simulate API call
+					time.Sleep(1000 * time.Millisecond)
+					return huh.NewOptions(s...)
+				}, &country /* only this function when `country` changes */),
 			huh.NewNote().
 				TitleFunc(func() string {
 					return fmt.Sprintf("You selected: %s", country)

field_select.go

@@ -4,8 +4,10 @@ import (
 	"fmt"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/charmbracelet/bubbles/key"
+	"github.com/charmbracelet/bubbles/spinner"
 	"github.com/charmbracelet/bubbles/textinput"
 	"github.com/charmbracelet/bubbles/viewport"
 	tea "github.com/charmbracelet/bubbletea"
@@ -40,6 +42,7 @@ type Select[T comparable] struct {
 	focused   bool
 	filtering bool
 	filter    textinput.Model
+	spinner   spinner.Model
 
 	// options
 	inline     bool
@@ -54,6 +57,8 @@ func NewSelect[T comparable]() *Select[T] {
 	filter := textinput.New()
 	filter.Prompt = "/"
 
+	s := spinner.New(spinner.WithSpinner(spinner.Line))
+
 	return &Select[T]{
 		value:       new(T),
 		validate:    func(T) error { return nil },
@@ -63,6 +68,7 @@ func NewSelect[T comparable]() *Select[T] {
 		options:     Eval[[]Option[T]]{cache: make(map[uint64][]Option[T])},
 		title:       Eval[string]{cache: make(map[uint64]string)},
 		description: Eval[string]{cache: make(map[uint64]string)},
+		spinner:     s,
 	}
 }
 
@@ -292,12 +298,21 @@ func (s *Select[T]) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				s.selected = clamp(s.selected, 0, len(s.options.val)-1)
 			} else {
 				s.options.loading = true
+				s.options.loadingStart = time.Now()
 				cmds = append(cmds, func() tea.Msg {
 					return updateOptionsMsg[T]{id: s.id, hash: hash, options: s.options.fn()}
-				})
+				}, s.spinner.Tick)
 			}
 		}
 		return s, tea.Batch(cmds...)
+
+	case spinner.TickMsg:
+		if !s.options.loading {
+			break
+		}
+		s.spinner, cmd = s.spinner.Update(msg)
+		return s, cmd
+
 	case updateTitleMsg:
 		if msg.id == s.id && msg.hash == s.title.bindingsHash {
 			s.title.update(msg.title)
@@ -481,6 +496,12 @@ func (s *Select[T]) optionsView() string {
 		sb     strings.Builder
 	)
 
+	if s.options.loading && time.Since(s.options.loadingStart) > spinnerShowThreshold {
+		s.spinner.Style = s.activeStyles().MultiSelectSelector.UnsetString()
+		sb.WriteString(s.spinner.View() + " Loading...")
+		return sb.String()
+	}
+
 	if s.inline {
 		sb.WriteString(styles.PrevIndicator.Faint(s.selected <= 0).String())
 		if len(s.filteredOptions) > 0 {