prime8dev

prime8dev
git clone https://git.prime8.dev/prime8dev.git
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render.go (1540B)

      1 package handlers
      2 
      3 import (
      4 	"crypto/sha256"
      5 	"fmt"
      6 	"net/http"
      7 	"os"
      8 	"strings"
      9 
     10 	"git.prime8.dev/moncheeta/prime8dev/internal/web"
     11 )
     12 
     13 func (h *Handler) renderTemplate(w http.ResponseWriter, r *http.Request, name string, data web.Data, maxAgeSeconds int) {
     14 	if maxAgeSeconds < 0 {
     15 		maxAgeSeconds = 0
     16 	}
     17 
     18 	data.Path = r.URL.Path
     19 	body, err := h.renderer.Render(name, data)
     20 	if err != nil {
     21 		http.Error(w, "Failed to render content", http.StatusInternalServerError)
     22 		return
     23 	}
     24 
     25 	sum := sha256.Sum256([]byte(body))
     26 	etag := fmt.Sprintf(`W/"%x"`, sum)
     27 	cacheEnabled := shouldCacheResponses()
     28 
     29 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
     30 	if !cacheEnabled || maxAgeSeconds == 0 {
     31 		applyNoCacheHeaders(w)
     32 	} else if maxAgeSeconds > 0 {
     33 		// revalidate every time (cheap 304 via ETag) so a deploy shows up at once;
     34 		// maxAgeSeconds now only gates whether caching/ETags apply at all.
     35 		w.Header().Set("Cache-Control", "public, no-cache")
     36 		w.Header().Set("ETag", etag)
     37 	}
     38 	w.Header().Set("Vary", "HX-Request")
     39 
     40 	if cacheEnabled && maxAgeSeconds > 0 && strings.Contains(r.Header.Get("If-None-Match"), etag) {
     41 		w.WriteHeader(http.StatusNotModified)
     42 		return
     43 	}
     44 
     45 	_, _ = w.Write([]byte(body))
     46 }
     47 
     48 func shouldCacheResponses() bool {
     49 	mode := strings.ToLower(strings.TrimSpace(os.Getenv("APP_ENV")))
     50 	return mode == "prod"
     51 }
     52 
     53 func applyNoCacheHeaders(w http.ResponseWriter) {
     54 	w.Header().Set("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0")
     55 	w.Header().Set("Pragma", "no-cache")
     56 	w.Header().Set("Expires", "0")
     57 }