wgoodall01/shikaku

package main

import (
    "html/template"
    "net/http"
    "sync"
)

func WriteError(w http.ResponseWriter, status int, msg string, err error) {

    type HttpError struct {
        Status  int
        Message string
    }

    // load the templates
    var tmpl *template.Template
    var loadTmpl sync.Once
    loadTmpl.Do(func() {
        tmpl = template.New("error.html")
        tmpl = tmpl.Funcs(map[string]interface{}{
            "statusText": func(status int) string {
                return http.StatusText(status)
            },
        })
        tmpl, err = tmpl.ParseFiles("templates/error.html")
        if err != nil {
            panic(err)
        }
    })

    w.WriteHeader(status)
    tmplErr := tmpl.Execute(w, HttpError{Status: status, Message: msg})
    if tmplErr != nil {
        panic(tmplErr)
    }
}

// Must panics if err != nil
func Must(err error) {
    if err != nil {
        panic(err)
    }
}