Dovetail

CURRENTLY IN ALPHA, API WILL CHANGE

Documentation

User- and developer-friendly HTML Components for Go, inspired by SwiftUI/React/Elm.

• Produce accessible HTML markup easily.
• Make components with functions.
• Supports ARIA and data attributes.
• Conveniences for forms and lists.

Render(
  w,
  Div(
    Header(
      Nav(
        AriaLabel("Primary"),
        List(
          Link("/", Text("Home")),
          Link("/about", Text("About")),
          Link("/pricing", Text("Pricing"), AriaCurrentPage),
          Link("/sign-in", Text("Sign In")),
          Link("/join", Text("Join")),
        ),
      ),
    ),
    Main(
      Article(
        H(1, Text("Welcome")),
        P("Render HTML using components with Go"),
      ),
      FormTo("/newsletter").With(
        FieldLabelled("Email", Textbox("email")),
        SubmitButton(Text("Sign up for the newsletter")),
      ),
    ),
  )
)

Provided components

Type: HTMLElementView

Landmarks

• Main(children ...HTMLView) — <main>
• Nav(children ...HTMLView) — <nav>
• Header(children ...HTMLView) — <header>
• Footer(children ...HTMLView) — <footer>
• Section(children ...HTMLView) — <section>
• Article(children ...HTMLView) — <article>
• Aside(children ...HTMLView) — <aside>

Structure

• Div(children ...HTMLView) — <div>
• List(children ...HTMLView) — <ul><li>{ children[0] }</li>…<li>{ children[n] }</li></ul>
• Ul(children ...HTMLView) — <ul>
• Li(children ...HTMLView) — <li>
• Coming soon: <ol>, <dl>

Elements

• Link(url string, children ...HTMLView) — <a href="{ url }">{ children }</a>
• Button(children ...HTMLView) — <button type="button">{ children }</button>
• Img(srcUrl string, alt string, enhancers ...HTMLEnhancer) — <img src="{ srcUrl }" alt="{ alt }" {...enhancers}>
• P(children ...HTMLView) — <p>
• TextWith(text string, enhancers ...HTMLEnhancer) — <span {...enhancers}>{ text }</span>
• Noscript(children ...HTMLView) — <noscript>{ children }</noscript>

Forms

• FormTo(action string, options ...func(form FormHTMLView) FormHTMLView) — <form>
  • Multipart(form FormHTMLView) FormHTMLView — <form enctype="multipart/form-data">
• Textbox(inputName string, options ...FieldTextInputOption) — <input type="text">
• SubmitButton(children ...HTMLView) — <button type="submit">{ children }</button>

Text nodes

• Text(text string) — HTML text node

Logic

• When(when bool, view HTMLView) — renders the provided view only if when is true

Custom

• HTMLElementViewOf(tagName string, tagAtom atom.Atom, children []HTMLView) — custom html element

Attributes

• AriaAttr — aria-*
• AriaLabel — aria-label
• CustomAttr — custom HTML attributes
• DataAttr — data-* attributes

Define components

Components are defined using functions. These functions can take any number of arguments, and return a composite of other components.

func PrimaryButton(text string) View {
	return Button(Text(text)).Class("btn btn-primary")
}

Performance

While not trying to be the fastest HTML producer possible, Dovetail aims to be faster than html/template to parse and execute.

Run make test_bench to see how Dovetail performs to produce a variety of HTML components. Here are results on a 2016 15″ MacBook Pro:

go test -p 1 -timeout 30s -bench="Bench" -benchmem -v -run "Bench" ./...
goos: darwin
goarch: amd64
pkg: github.com/RoyalIcing/dovetail
BenchmarkTailwindJustDiv-8                  	 4758601	       247 ns/op	     272 B/op	       2 allocs/op
BenchmarkTailwind0Classes-8                 	 4620313	       249 ns/op	     272 B/op	       2 allocs/op
BenchmarkTailwind2Classes-8                 	 2074034	       580 ns/op	     400 B/op	       6 allocs/op
BenchmarkTailwind4Classes-8                 	 1713938	       694 ns/op	     464 B/op	       7 allocs/op
BenchmarkTailwind8Classes-8                 	 1349778	       887 ns/op	     640 B/op	       8 allocs/op
BenchmarkTailwindAddClasses2Classes-8       	 1990402	       601 ns/op	     416 B/op	       6 allocs/op
BenchmarkTailwindAddClasses4Classes-8       	 1771840	       677 ns/op	     480 B/op	       6 allocs/op
BenchmarkTailwindAddClasses8Classes-8       	 1504893	       783 ns/op	     656 B/op	       6 allocs/op
BenchmarkTailwindDivWithClasses8Classes-8   	 1757682	       729 ns/op	     528 B/op	       5 allocs/op
BenchmarkTailwindChangeClasses2Classes-8    	 1797513	       643 ns/op	     464 B/op	       8 allocs/op
BenchmarkTailwindChangeClasses4Classes-8    	 1533936	       790 ns/op	     560 B/op	       9 allocs/op
BenchmarkTailwindChangeClasses8Classes-8    	 1234028	       970 ns/op	     800 B/op	      10 allocs/op
BenchmarkText-8                             	 7639869	       154 ns/op	     128 B/op	       2 allocs/op
BenchmarkHeader-8                           	 4320638	       251 ns/op	     272 B/op	       2 allocs/op
BenchmarkDiv-8                              	 4858587	       242 ns/op	     272 B/op	       2 allocs/op
BenchmarkDivWithClasses1-8                  	 2697412	       445 ns/op	     336 B/op	       4 allocs/op
BenchmarkDivWithClasses2Together-8          	 2296304	       519 ns/op	     368 B/op	       5 allocs/op
BenchmarkDivWithClasses2-8                  	 2066386	       576 ns/op	     384 B/op	       6 allocs/op
BenchmarkDivWithChildClassNames-8           	 1734169	       672 ns/op	     448 B/op	       9 allocs/op
BenchmarkButton-8                           	 2446404	       478 ns/op	     352 B/op	       5 allocs/op
BenchmarkButtonSubmit-8                     	 2451301	       480 ns/op	     352 B/op	       5 allocs/op
BenchmarkH1-8                               	 2267946	       521 ns/op	     448 B/op	       6 allocs/op
PASS
ok  	github.com/RoyalIcing/dovetail	39.216s

Why?

Because I want to create server-rendered web apps that I can host cheaply on GCP App Engine Standard.

I want something that is both user friendly (quick to load, accessible) while also being developer friendly.