// Copyright 2015 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package template_test import ( "fmt" "html/template" "log" "os" "strings" ) func Example() { const tpl = ` <!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>{{.Title}}</title> </head> <body> {{range .Items}}<div>{{ . }}</div>{{else}}<div><strong>no rows</strong></div>{{end}} </body> </html>` check := func(err error) { if err != nil { log.Fatal(err) } } t, err := template.New("webpage").Parse(tpl) check(err) data := struct { Title string Items []string }{ Title: "My page", Items: []string{ "My photos", "My blog", }, } err = t.Execute(os.Stdout, data) check(err) noItems := struct { Title string Items []string }{ Title: "My another page", Items: []string{}, } err = t.Execute(os.Stdout, noItems) check(err) // Output: // <!DOCTYPE html> // <html> // <head> // <meta charset="UTF-8"> // <title>My page</title> // </head> // <body> // <div>My photos</div><div>My blog</div> // </body> // </html> // <!DOCTYPE html> // <html> // <head> // <meta charset="UTF-8"> // <title>My another page</title> // </head> // <body> // <div><strong>no rows</strong></div> // </body> // </html> } func Example_autoescaping() { check := func(err error) { if err != nil { log.Fatal(err) } } t, err := template.New("foo").Parse(`{{define "T"}}Hello, {{.}}!{{end}}`) check(err) err = t.ExecuteTemplate(os.Stdout, "T", "<script>alert('you have been pwned')</script>") check(err) // Output: // Hello, <script>alert('you have been pwned')</script>! } func Example_escape() { const s = `"Fran & Freddie's Diner" <tasty@example.com>` v := []interface{}{`"Fran & Freddie's Diner"`, ' ', `<tasty@example.com>`} fmt.Println(template.HTMLEscapeString(s)) template.HTMLEscape(os.Stdout, []byte(s)) fmt.Fprintln(os.Stdout, "") fmt.Println(template.HTMLEscaper(v...)) fmt.Println(template.JSEscapeString(s)) template.JSEscape(os.Stdout, []byte(s)) fmt.Fprintln(os.Stdout, "") fmt.Println(template.JSEscaper(v...)) fmt.Println(template.URLQueryEscaper(v...)) // Output: // "Fran & Freddie's Diner" <tasty@example.com> // "Fran & Freddie's Diner" <tasty@example.com> // "Fran & Freddie's Diner"32<tasty@example.com> // \"Fran & Freddie\'s Diner\" \x3Ctasty@example.com\x3E // \"Fran & Freddie\'s Diner\" \x3Ctasty@example.com\x3E // \"Fran & Freddie\'s Diner\"32\x3Ctasty@example.com\x3E // %22Fran+%26+Freddie%27s+Diner%2232%3Ctasty%40example.com%3E } // The following example is duplicated in text/template; keep them in sync. func ExampleTemplate_block() { const ( master = `Names:{{block "list" .}}{{"\n"}}{{range .}}{{println "-" .}}{{end}}{{end}}` overlay = `{{define "list"}} {{join . ", "}}{{end}} ` ) var ( funcs = template.FuncMap{"join": strings.Join} guardians = []string{"Gamora", "Groot", "Nebula", "Rocket", "Star-Lord"} ) masterTmpl, err := template.New("master").Funcs(funcs).Parse(master) if err != nil { log.Fatal(err) } overlayTmpl, err := template.Must(masterTmpl.Clone()).Parse(overlay) if err != nil { log.Fatal(err) } if err := masterTmpl.Execute(os.Stdout, guardians); err != nil { log.Fatal(err) } if err := overlayTmpl.Execute(os.Stdout, guardians); err != nil { log.Fatal(err) } // Output: // Names: // - Gamora // - Groot // - Nebula // - Rocket // - Star-Lord // Names: Gamora, Groot, Nebula, Rocket, Star-Lord }