Template (Func) in Go

Posted by GoDoc

Public (Editable by Users)

This example demonstrates a custom function to process template text. It installs the strings.Title function and uses it to Make Title Text Look Good In Our Template's Output.

Language Go

Dependencies

import "log"

import "os"

import "strings"

import "text/template"

Edit

main.go

package main

import (
	"log"
	"os"
	"strings"
	"text/template"
)

func main() {
	// First we create a FuncMap with which to register the function.
	funcMap := template.FuncMap{
		// The name "title" is what the function will be called in the template text.
		"title": strings.Title,
	}

	// A simple template definition to test our function.
	// We print the input text several ways:
	// - the original
	// - title-cased
	// - title-cased and then printed with %q
	// - printed with %q and then title-cased.
	const templateText = `
Input: {{printf "%q" .}}
Output 0: {{title .}}
Output 1: {{title . | printf "%q"}}
Output 2: {{printf "%q" . | title}}
`

	// Create a template, add the function map, and parse the text.
	tmpl, err := template.New("titleTest").Funcs(funcMap).Parse(templateText)
	if err != nil {
		log.Fatalf("parsing: %s", err)
	}

	// Run the template to verify the output.
	err = tmpl.Execute(os.Stdout, "the go programming language")
	if err != nil {
		log.Fatalf("execution: %s", err)
	}
}

Stdout
Stderr