Add Treilik-inspired example for sending value along on exit

examples/result/main.go

@@ -0,0 +1,104 @@
+package main
+
+// A simple example that shows how to retrieve a value from a Bubble Tea
+// program after the Bubble Tea has exited.
+//
+// Thanks to Treilik for this one.
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+var (
+	choices = []string{"Taro", "Coffee", "Lychee"}
+)
+
+type model struct {
+	cursor int
+	choice chan string
+}
+
+func main() {
+	// This is where we'll listen for the choice the user makes in the Bubble
+	// Tea program.
+	result := make(chan string, 1)
+
+	// Pass the channel to the initialize function so our Bubble Tea program
+	// can send the final choice along when the time comes.
+	if err := tea.NewProgram(initialize(result), update, view).Start(); err != nil {
+		fmt.Println("Oh no:", err)
+		os.Exit(1)
+	}
+
+	// Print out the final choice.
+	if r := <-result; r != "" {
+		fmt.Printf("\n---\nYou chose %s!\n", r)
+	}
+}
+
+// Pass a channel to the model to listen to the result value. This is a
+// function that returns the initialize function and is typically how you would
+// pass arguments to a tea.Init function.
+func initialize(choice chan string) func() (tea.Model, tea.Cmd) {
+	return func() (tea.Model, tea.Cmd) {
+		return model{cursor: 0, choice: choice}, nil
+	}
+}
+
+func update(msg tea.Msg, mdl tea.Model) (tea.Model, tea.Cmd) {
+	m, _ := mdl.(model)
+
+	switch msg := msg.(type) {
+	case tea.KeyMsg:
+		switch msg.String() {
+
+		case "ctrl+c", "q":
+			close(m.choice) // If we're quitting just chose the channel.
+			return m, tea.Quit
+
+		case "enter":
+			// Send the choice on the channel and exit.
+			m.choice <- choices[m.cursor]
+			return m, tea.Quit
+
+		case "down", "j":
+			m.cursor++
+			if m.cursor >= len(choices) {
+				m.cursor = 0
+			}
+
+		case "up", "k":
+			m.cursor--
+			if m.cursor < 0 {
+				m.cursor = len(choices) - 1
+			}
+		}
+
+	}
+
+	return m, nil
+}
+
+func view(mdl tea.Model) string {
+	m, _ := mdl.(model)
+
+	s := strings.Builder{}
+	s.WriteString("What kind of Bubble Tea would you like to order?\n\n")
+
+	for i := 0; i < len(choices); i++ {
+		if m.cursor == i {
+			s.WriteString("(•) ")
+		} else {
+			s.WriteString("( ) ")
+		}
+		s.WriteString(choices[i])
+		s.WriteString("\n")
+	}
+	s.WriteString("\n(press q to quit)\n")
+
+	return s.String()
+}