maragudk / gomponents

View components in pure Go, that render to HTML 5.

Tired of complex template languages?

Try HTML components in pure Go.

gomponents are HTML components written in pure Go. They render to HTML 5, and make it easy for you to build reusable components. So you can focus on building your app instead of learning yet another templating language.

The API may change until version 1 is reached.

Check out www.gomponents.com for an introduction.

Made in 🇩🇰 by maragu, maker of online Go courses.

Features

• Build reusable HTML components
• Write declarative HTML5 in Go without all the strings, so you get
  • Type safety
  • Auto-completion
  • Nice formatting with gofmt
• Simple API that's easy to learn and use (you know most already if you know HTML)
• Useful helpers like Text and Textf that insert HTML-escaped text, Map for mapping data to components, and If for conditional rendering.
• No external dependencies

Usage

Get the library using go get:

go get github.com/maragudk/gomponents

The preferred way to use gomponents is with so-called dot-imports (note the dot before the gomponents/html import), to give you that smooth, native HTML feel:

package main

import (
	"net/http"

	g "github.com/maragudk/gomponents"
	c "github.com/maragudk/gomponents/components"
	. "github.com/maragudk/gomponents/html"
)

func main() {
	_ = http.ListenAndServe("localhost:8080", http.HandlerFunc(handler))
}

func handler(w http.ResponseWriter, r *http.Request) {
	_ = Page("Hi!", r.URL.Path).Render(w)
}

func Page(title, currentPath string) g.Node {
	return Doctype(
		HTML(
			Lang("en"),
			Head(
				TitleEl(g.Text(title)),
				StyleEl(Type("text/css"), g.Raw(".is-active{ font-weight: bold }")),
			),
			Body(
				Navbar(currentPath),
				H1(g.Text(title)),
				P(g.Textf("Welcome to the page at %v.", currentPath)),
			),
		),
	)
}

func Navbar(currentPath string) g.Node {
	return Nav(
		NavbarLink("/", "Home", currentPath),
		NavbarLink("/about", "About", currentPath),
	)
}

func NavbarLink(href, name, currentPath string) g.Node {
	return A(Href(href), c.Classes{"is-active": currentPath == href}, g.Text(name))
}

Some people don't like dot-imports, and luckily it's completely optional. If you don't like dot-imports, just use regular imports.

You could also use the provided HTML5 document template to simplify your code a bit:

package main

import (
	"net/http"

	g "github.com/maragudk/gomponents"
	c "github.com/maragudk/gomponents/components"
	. "github.com/maragudk/gomponents/html"
)

func main() {
	_ = http.ListenAndServe("localhost:8080", http.HandlerFunc(handler))
}

func handler(w http.ResponseWriter, r *http.Request) {
	_ = Page("Hi!", r.URL.Path).Render(w)
}

func Page(title, currentPath string) g.Node {
	return c.HTML5(c.HTML5Props{
		Title:    title,
		Language: "en",
		Head: []g.Node{
			StyleEl(Type("text/css"), g.Raw(".is-active{ font-weight: bold }")),
		},
		Body: []g.Node{
			Navbar(currentPath),
			H1(g.Text(title)),
			P(g.Textf("Welcome to the page at %v.", currentPath)),
		},
	})
}

func Navbar(currentPath string) g.Node {
	return Nav(
		NavbarLink("/", "Home", currentPath),
		NavbarLink("/about", "About", currentPath),
	)
}

func NavbarLink(href, name, currentPath string) g.Node {
	return A(Href(href), c.Classes{"is-active": currentPath == href}, g.Text(name))
}

For more complete examples, see the examples directory.

What's up with the specially named elements and attributes?

Unfortunately, there are four main name clashes in HTML elements and attributes, so they need an El or Attr suffix, respectively, to be able to co-exist in the same package in Go:

• data (DataEl/DataAttr)
• form (FormEl/FormAttr)
• style (StyleEl/StyleAttr)
• title (TitleEl/TitleAttr)