package main // A simple program that counts down from 5 and then exits. import ( "errors" "fmt" "log" "github.com/charmbracelet/tea" "github.com/charmbracelet/teaparty/input" ) type Model struct { Input input.Model Error error } type tickMsg struct{} func main() { tea.UseSysLog("tea") p := tea.NewProgram( Model{ Input: input.DefaultModel(), Error: nil, }, update, view, []tea.Sub{ // We just hand off the subscription to the input component, giving // it the model it expects. func(model tea.Model) tea.Msg { m, ok := model.(Model) if !ok { return tea.NewErrMsg("could not perform assertion on model") } return input.Blink(m.Input) }, }, ) if err := p.Start(); err != nil { log.Fatal(err) } } func update(msg tea.Msg, model tea.Model) (tea.Model, tea.Cmd) { var cmd tea.Cmd m, ok := model.(Model) if !ok { // When we encounter errors in Update we simply add the error to the // model so we can handle it in the view. We could also return a command // that does something else with the error, like logs it via IO. m.Error = errors.New("could not perform assertion on model") return m, nil } switch msg := msg.(type) { case tea.KeyMsg: switch msg.String() { case "break": fallthrough case "esc": return m, tea.Quit } // We handle errors just like any other message case tea.ErrMsg: m.Error = msg return m, nil } m.Input, cmd = input.Update(msg, m.Input) return m, cmd } func view(model tea.Model) string { m, ok := model.(Model) if !ok { return "Oh no: could not perform assertion on model." } else if m.Error != nil { return fmt.Sprintf("Uh oh: %s", m.Error) } return fmt.Sprintf( "What’s your favorite Pokémon?\n\n%s\n\n%s", input.View(m.Input), "(esc to quit)", ) }