guestbook/cmd/web/helpers.go

100 lines
2.3 KiB
Go

package main
import (
"errors"
"fmt"
"math"
"net/http"
"strconv"
"time"
"github.com/gorilla/schema"
)
func (app *application) serverError(w http.ResponseWriter, r *http.Request, err error) {
var (
method = r.Method
uri = r.URL.RequestURI()
)
app.logger.Error(err.Error(), "method", method, "uri", uri)
http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
}
func (app *application) clientError(w http.ResponseWriter, status int) {
http.Error(w, http.StatusText(status), status)
}
func (app *application) render(w http.ResponseWriter, r *http.Request, status int, page string, data templateData) {
ts, ok := app.templateCache[page]
if !ok {
err := fmt.Errorf("the template %s does not exist", page)
app.serverError(w, r, err)
return
}
w.WriteHeader(status)
err := ts.ExecuteTemplate(w, "base", data)
if err != nil {
app.serverError(w, r, err)
}
}
func (app *application) nextSequence () uint16 {
val := app.sequence
if app.sequence == math.MaxUint16 {
app.sequence = 0
} else {
app.sequence += 1
}
return val
}
func (app *application) createShortId () uint64 {
now := time.Now().UTC()
epoch, err := time.Parse(time.RFC822Z, "01 Jan 20 00:00 -0000")
if err != nil {
fmt.Println(err)
return 0
}
d := now.Sub(epoch)
ms := d.Milliseconds()
seq := app.nextSequence()
return (uint64(ms) & 0x0FFFFFFFFFFFFFFF) | (uint64(seq) << 48)
}
func shortIdToSlug(id uint64) string {
slug := strconv.FormatUint(id, 36)
return slug
}
func slugToShortId(slug string) uint64 {
id, _ := strconv.ParseUint(slug, 36, 64)
return id
}
func (app *application) decodePostForm(r *http.Request, dst any) error {
err := r.ParseForm()
if err != nil {
return err
}
err = app.formDecoder.Decode(dst, r.PostForm)
if err != nil {
var multiErrors *schema.MultiError
if !errors.As(err, &multiErrors) {
panic(err)
}
return err
}
return nil
}
func (app *application) isAuthenticated(r *http.Request) bool {
isAuthenticated, ok := r.Context().Value(isAuthenticatedContextKey).(bool)
if !ok {
return false
}
return isAuthenticated
}