Go HTML Templates

go template example

header.html

<!-- partials/header.html -->
{{define "header"}}
<header>
  <h2>My website</h2>
</header>
{{end}}

homepage.html

<!-- homebase.html -->
<!-- Html template for homepage referenced in homepage Page struct
     instance. These files can be anywhere in the project but should
     be collocated with file where Page struct is defined. -->

<!-- Because we are passing a string as data we can just inpolate
     it with a dot -->
<title>{{.}}</title>

{{template "header"}}
<h1>Welcome to {{.}}</h1>

server.go

// server.go
package main

import (
	html "html/template"
	"log"
	"net/http"
)

// baseTemplate to base other templates on so partials are preloaded
var baseTemplate *html.Template

// Page struct can be reference anywhere in the project, if you are in a
// different package you have to add an import but all fields are public.
type Page struct {
	// Template html file for this page
	Template string
	// Params generator function to produce params for the view based on
	// the request
	Params func(r *http.Request) interface{}
}

// ServeHTTP fulfills http.Handler interface, right now just rendering
// a template
func (p Page) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	t := html.Must(baseTemplate.Clone())
	html.Must(t.ParseFiles(p.Template))

	if p.Params == nil {
		t.Execute(w, nil)
	} else {
		t.ExecuteTemplate(w, p.Template, p.Params(r))
	}
}

// Creating a instance of a page for the homepage, this can be done in a
// different file for more complexity or code organization
var homepage = Page{
	Template: "homepage.html",
	Params: func(r *http.Request) interface{} {
		return "Homebase Homepage"
	},
}

// Finally setup and run the server using go's http basic package
func main() {
	// Loading in partial files
	baseTemplate = html.New("base")
	html.Must(baseTemplate.ParseGlob("partials/*.html"))

	http.Handle("/", homepage)
	log.Println("Server running at 127.0.0.1:8000")
	http.ListenAndServe(":8000", nil)
}