udemy-go-web-1/internal/render/render.go
2024-07-26 13:40:56 +02:00

142 lines
3.0 KiB
Go

package render
import (
"bytes"
"errors"
"fmt"
"go-udemy-web-1/internal/config"
"go-udemy-web-1/internal/helpers"
"go-udemy-web-1/internal/models"
"html/template"
"net/http"
"path/filepath"
"time"
"github.com/justinas/nosurf"
)
var functions = template.FuncMap{
"humanDate": HumanDate,
"formatDate": FormatDate,
"iterate": Iterate,
"add": Add,
}
var (
app *config.AppConfig
pathToTemplates = "./templates"
)
// NewRenderer sets the config for the template package
func NewRenderer(a *config.AppConfig) {
app = a
}
// HumanDate returns formatted time
func HumanDate(t time.Time) string {
return t.Format("2006-01-02")
}
func FormatDate(t time.Time, f string) string {
return t.Format(f)
}
// Iterate returns a slice of ints, starting at 1, going to count
func Iterate(count int) []int {
var i int
var items []int
for i = 0; i < count; i++ {
items = append(items, i)
}
return items
}
func Add(a, b int) int {
return a + b
}
// AddDefaultData adds default template data
func AddDefaultData(td *models.TemplateData, r *http.Request) *models.TemplateData {
td.Flash = app.Session.PopString(r.Context(), "flash")
td.Warning = app.Session.PopString(r.Context(), "warning")
td.Error = app.Session.PopString(r.Context(), "error")
td.CSRFToken = nosurf.Token(r)
if app.Session.Exists(r.Context(), "user_id") {
td.IsAuthenticated = 1
}
return td
}
// Template renders a HTML template file
func Template(w http.ResponseWriter, r *http.Request, tmpl string, td *models.TemplateData) error {
var tc map[string]*template.Template
if app.UseCache {
// get the template cache from the app config
tc = app.TemplateCahce
} else {
tc, _ = CreateTemplateCache()
}
// get requested template from cache
t, ok := tc[tmpl]
if !ok {
return errors.New("could not get template from template cache")
}
// Write to a buffer to make sure that the template can be read and
// written successfully
buf := new(bytes.Buffer)
td = AddDefaultData(td, r)
err := t.Execute(buf, td)
if err != nil {
helpers.ServerError(w, err)
return err
}
// render the template
_, err = buf.WriteTo(w)
if err != nil {
helpers.ServerError(w, err)
return err
}
return nil
}
func CreateTemplateCache() (map[string]*template.Template, error) {
myCache := map[string]*template.Template{}
// get all of the files named *.page.tmpl from templates
pages, err := filepath.Glob(fmt.Sprintf("%s/*.page.tmpl", pathToTemplates))
if err != nil {
return myCache, err
}
// range through all files ending with *page.tmpl
for _, page := range pages {
name := filepath.Base(page)
ts, err := template.New(name).Funcs(functions).ParseFiles(page)
if err != nil {
return myCache, err
}
matches, err := filepath.Glob(fmt.Sprintf("%s/*.layout.tmpl", pathToTemplates))
if err != nil {
return myCache, err
}
if len(matches) > 0 {
ts, err = ts.ParseGlob(fmt.Sprintf("%s/*.layout.tmpl", pathToTemplates))
if err != nil {
return myCache, err
}
}
myCache[name] = ts
}
return myCache, nil
}