html_generator_example.go

html_generator_example.go

// Go Playground: https://go.dev/play/p/ao7M54vTDRQ

package main

import (
	"os"
	"strings"

	"golang.org/x/net/html"
)

type Attr = map[string]string

func Comment(data string) *html.Node {
	return &html.Node{Type: html.CommentNode, Data: data}
}

func TextNode(data string) *html.Node {
	return &html.Node{Type: html.TextNode, Data: data}
}

func makeNode(nt html.NodeType, tag string, attributes Attr, children ...*html.Node) *html.Node {
	node := &html.Node{Type: nt, Data: tag}
	for k, v := range attributes {
		if ns, key, found := strings.Cut(k, ":"); found {
			node.Attr = append(node.Attr, html.Attribute{Namespace: ns, Key: key, Val: v})
		} else {
			node.Attr = append(node.Attr, html.Attribute{Key: k, Val: v})
		}
	}
	for _, c := range children {
		if c != nil {
			node.AppendChild(c)
		}
	}
	return node
}

func Element(tag string, attributes Attr, children ...*html.Node) *html.Node {
	return makeNode(html.ElementNode, tag, attributes, children...)
}

func Elem(tag string, children ...*html.Node) *html.Node {
	return Element(tag, nil, children...)
}

func HtmlDocument(children ...*html.Node) *html.Node {
	return makeNode(html.DocumentNode, "", nil, children...)
}

func NL() *html.Node { return TextNode("\n") } // Makes reading the output easier.

////////////////////////////////////////////////////////////////////////////////

func main() {
	html.Render(os.Stdout,
		HtmlDocument(
			&html.Node{Type: html.DoctypeNode, Data: "html"}, NL(),
			Element("html",
				Attr{"lang": "en"}, NL(),
				Elem("head", NL(),
					Element("meta", Attr{"charset": "utf-8"}), NL(),
					Comment(" HELLO WORLD "), NL(),
					Element("meta", Attr{"name": "viewport", "content": "width=device-width, initial-scale=1.0"}), NL(),
					Elem("title", TextNode("HELLO WORLD")), NL(),
					Elem("style", TextNode("\nbody{max-width:35em;margin:22px auto 64px auto;padding:0 8px;}\n")), NL(),
				), NL(),
				Elem("body", NL(),
					Elem("h1", TextNode("HELLO,")), NL(),
					Elem("p", TextNode("world!")), NL(),
				), NL(),
			),
		),
	)
}