3  Things  You  May  Not   Know  About  The  Go   Template  Engine   Chang  Sau  Sheong   Feb  2015   

Obligatory  stuff   

What  is  a  template   engine?   

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No content

Where’s  Go  template  engine?   Logic-­‐less   Go   template   engine   Embedded   logic   Mustache,  Handlebars  etc   JSP,  Haml,  Jade  etc   

How  does  the  Go  template   engine  work?   

text/template   html/template   

Parse   template   Execute   template   

Go Web Programming {{ . }} 

package main import ( "net/http" "html/template" ) func process(w http.ResponseWriter, r *http.Request) { t, _ := template.ParseFiles("tmpl.html") t.Execute(w, "Hello World!") } func main() { server := http.Server{ Addr: "127.0.0.1:8080", } http.HandleFunc("/process", process) server.ListenAndServe() } 

The  Go  template  engine  is   kinda  cool   

1.  Pipelines   

{{ p1 | p2 | p3 }} 

Go Web Programming {{ 12.3456 | printf "%.2f" }} 

2.  FuncTons   

func formatDate(t time.Time) string { layout := "2006-01-02" return t.Format(layout) } func process(w http.ResponseWriter, r *http.Request) { funcMap := template.FuncMap { "fdate": formatDate } t := template.New("tmpl.html").Funcs(funcMap) t, _ = t.ParseFiles("tmpl.html") t.Execute(w, time.Now()) } 

Go Web Programming 

Go Web Programming 

3.  Context  aware   

func process(w http.ResponseWriter, r *http.Request) { t, _ := template.ParseFiles("tmpl.html") content := `I asked: "What's up?"` t.Execute(w, content) } 

Go Web Programming 

Go Web Programming 

Context Content Original text I asked: "What's up?" {{ . }} I asked: <i>"What's up?"</i> I%20asked:%20%3ci%3e%22What%27s%20up?%22%3c/i%3e I%20asked%3a%20%3ci%3e%22What%27s%20up%3f%22%3c %2fi%3e I asked: \x3ci\x3e\x22What\x27s up?\x22\x3c\/i\x3e 

XSS   

XSS  Demo     

hWp://manning.com/chang   

Thank  you   [email protected]   @sausheong