huh: Build Interactive Terminal Forms and Prompts in Go

Introduction

huh is a robust and user-friendly Go library developed by Charmbracelet, specifically engineered for building interactive forms and prompts within the terminal. It empowers developers to create engaging command-line interfaces with a variety of input fields, making CLI applications more dynamic and user-friendly. Whether you need to gather simple text input, allow users to select from a list, or confirm actions, huh provides an elegant solution.

Key features of huh include:

• A comprehensive set of field types: Input, Text, Select, MultiSelect, and Confirm.
• Support for multi-page forms using groups.
• Built-in validation for fields.
• An accessible mode for screen readers.
• Customizable themes to match your application's aesthetic.
• Seamless integration with Charmbracelet's Bubble Tea framework.
• Dynamic forms that adapt based on user input.

Installation

Getting started with huh is straightforward. You can add it to your Go project using the standard go get command:

go get github.com/charmbracelet/huh

Examples

huh makes it easy to create both simple prompts and complex multi-page forms. Here's a quick example demonstrating a single input field:

package main

import (
	"fmt"
	"log"

	"github.com/charmbracelet/huh"
)

func main() {
	var name string

	err := huh.NewInput().
		Title("What’s your name?").
		Value(&name).
		Run() // this is blocking...

	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("Hey, %s!\n", name)
}

For more elaborate scenarios, huh allows you to construct multi-group forms with various field types. Below is an excerpt from a burger ordering form, showcasing Select, MultiSelect, Input, Text, and Confirm fields:

package main

import (
	"errors"
	"fmt"
	"log"

	"github.com/charmbracelet/huh"
)

var (
	burger       string
	toppings     []string
	sauceLevel   int
	name         string
	instructions string
	discount     bool
)

func main() {
	form := huh.NewForm(
		huh.NewGroup(
			huh.NewSelect[string]().
				Title("Choose your burger").
				Options(
					huh.NewOption("Charmburger Classic", "classic"),
					huh.NewOption("Chickwich", "chickwich"),
					huh.NewOption("Fishburger", "fishburger"),
					huh.NewOption("Charmpossible™ Burger", "charmpossible"),
				).
				Value(&burger),

			huh.NewMultiSelect[string]().
				Title("Toppings").
				Options(
					huh.NewOption("Lettuce", "lettuce").Selected(true),
					huh.NewOption("Tomatoes", "tomatoes").Selected(true),
					huh.NewOption("Jalapeños", "jalapeños"),
					huh.NewOption("Cheese", "cheese"),
					huh.NewOption("Vegan Cheese", "vegan cheese"),					
					huh.NewOption("Nutella", "nutella"),
				).
				Limit(4).
				Value(&toppings),

			huh.NewSelect[int]().
				Title("How much Charm Sauce do you want?").
				Options(
					huh.NewOption("None", 0),
					huh.NewOption("A little", 1),
					huh.NewOption("A lot", 2),
				).
				Value(&sauceLevel),
		),

		huh.NewGroup(
			huh.NewInput().
				Title("What’s your name?").
				Value(&name).
				Validate(func(str string) error {
					if str == "Frank" {
						return errors.New("Sorry, we don’t serve customers named Frank.")
					}
					return nil
				}),

			huh.NewText().
				Title("Special Instructions").
				CharLimit(400).
				Value(&instructions),

			huh.NewConfirm().
				Title("Would you like 15% off?").
				Value(&discount),
		),
	)

	err := form.Run()
	if err != nil {
		log.Fatal(err)
	}

	if !discount {
		fmt.Println("What? You didn’t take the discount?!\n")
	}
}

huh also supports dynamic forms, where fields can change based on previous inputs, and an accessible mode for improved usability with screen readers.

Why Use huh?

huh stands out for several reasons, making it an excellent choice for developers looking to enhance their CLI applications:

• Simplicity and Power: It offers a clean and intuitive API that allows for the rapid development of complex interactive forms.
• Rich User Experience: By bringing interactive forms to the terminal, huh elevates the user experience of command-line tools beyond simple text prompts.
• Flexibility: With a variety of field types, validation capabilities, and dynamic form features, huh can adapt to almost any input requirement.
• Accessibility: The dedicated accessible mode ensures that your CLI applications are usable by a wider audience, including those who rely on screen readers.
• Customization: Theming options allow you to tailor the look and feel of your forms to perfectly match your brand or application's style.
• Bubble Tea Integration: For those building more extensive Terminal User Interface (TUI) applications with Bubble Tea, huh integrates seamlessly, acting as a tea.Model for advanced control.

Links

• GitHub Repository: https://github.com/charmbracelet/huh
• Go Documentation: https://pkg.go.dev/github.com/charmbracelet/huh?tab=doc
• Charmbracelet: https://charm.sh