github.com/kovansky/hugo@v0.92.3-0.20220224232819-63076e4ff19f/tpl/internal/go_templates/texttemplate/examplefunc_test.go (about)

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build go1.13
     6  
     7  package template_test
     8  
     9  import (
    10  	"log"
    11  	"os"
    12  	"strings"
    13  	"text/template"
    14  )
    15  
    16  // This example demonstrates a custom function to process template text.
    17  // It installs the strings.Title function and uses it to
    18  // Make Title Text Look Good In Our Template's Output.
    19  func ExampleTemplate_func() {
    20  	// First we create a FuncMap with which to register the function.
    21  	funcMap := template.FuncMap{
    22  		// The name "title" is what the function will be called in the template text.
    23  		"title": strings.Title,
    24  	}
    25  
    26  	// A simple template definition to test our function.
    27  	// We print the input text several ways:
    28  	// - the original
    29  	// - title-cased
    30  	// - title-cased and then printed with %q
    31  	// - printed with %q and then title-cased.
    32  	const templateText = `
    33  Input: {{printf "%q" .}}
    34  Output 0: {{title .}}
    35  Output 1: {{title . | printf "%q"}}
    36  Output 2: {{printf "%q" . | title}}
    37  `
    38  
    39  	// Create a template, add the function map, and parse the text.
    40  	tmpl, err := template.New("titleTest").Funcs(funcMap).Parse(templateText)
    41  	if err != nil {
    42  		log.Fatalf("parsing: %s", err)
    43  	}
    44  
    45  	// Run the template to verify the output.
    46  	err = tmpl.Execute(os.Stdout, "the go programming language")
    47  	if err != nil {
    48  		log.Fatalf("execution: %s", err)
    49  	}
    50  
    51  	// Output:
    52  	// Input: "the go programming language"
    53  	// Output 0: The Go Programming Language
    54  	// Output 1: "The Go Programming Language"
    55  	// Output 2: "The Go Programming Language"
    56  }