Go templates pipelines

This example demonstrates Go template pipelines with custom functions registered via template.FuncMap. It defines helper functions for date formatting, doubling a number, computing square roots, and squaring values. These functions are registered on the template engine so they can be called directly within .gohtml template files using the pipeline syntax.

package main

import (
	"os"
	"time"
	"fmt"
	"log"
	"math"
	"text/template"
)

var tpl *template.Template

func init() {
	fmt.Println("Initializing ...")
	// tpl = template.Must(template.ParseGlob("*.gohtml"))
	//  to incorporate some extra function into template object
	tpl = template.Must(template.New("").Funcs(fm).ParseGlob("pipelines.gohtml"))
}

//  define several functions to be used in templating
func monthDayYear(t time.Time) string{
	return t.Format("01-02-2006")
}




func double(x int) int {
	return x + x
}

func sqRoot(x float64) float64 {
	return math.Sqrt(x)
}

func square(x int) float64 {
	return math.Pow(float64(x), 2)
}

var fm = template.FuncMap{
	"fdateMDY": monthDayYear,
	"fdbl": double,
	"fsqrt": sqRoot,
	"fsq": square,
}


func main()  {

	// err := tpl.ExecuteTemplate(os.Stdout, "dateformatting.gohtml", time.Now())
	err := tpl.ExecuteTemplate(os.Stdout, "pipelines.gohtml", 3)

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



}