Refactor template render (#36438)

modules/templates/page.go

@@ -0,0 +1,98 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package templates
+
+import (
+	"context"
+	"html/template"
+	"io"
+	"net/http"
+	"slices"
+	"strings"
+	"sync"
+	texttemplate "text/template"
+
+	"code.gitea.io/gitea/modules/graceful"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+)
+
+type pageRenderer struct {
+	tmplRenderer *tmplRender
+}
+
+func (r *pageRenderer) funcMap(ctx context.Context) template.FuncMap {
+	pageFuncMap := NewFuncMap()
+	pageFuncMap["ctx"] = func() any { return ctx }
+	return pageFuncMap
+}
+
+func (r *pageRenderer) funcMapDummy() template.FuncMap {
+	dummyFuncMap := NewFuncMap()
+	dummyFuncMap["ctx"] = func() any { return nil } // for template compilation only, no context available
+	return dummyFuncMap
+}
+
+func (r *pageRenderer) TemplateLookup(tmpl string, templateCtx context.Context) (TemplateExecutor, error) { //nolint:revive // we don't use ctx, only pass it to the template executor
+	return r.tmplRenderer.Templates().Executor(tmpl, r.funcMap(templateCtx))
+}
+
+func (r *pageRenderer) HTML(w io.Writer, status int, tplName TplName, data any, templateCtx context.Context) error { //nolint:revive // we don't use ctx, only pass it to the template executor
+	name := string(tplName)
+	if respWriter, ok := w.(http.ResponseWriter); ok {
+		if respWriter.Header().Get("Content-Type") == "" {
+			respWriter.Header().Set("Content-Type", "text/html; charset=utf-8")
+		}
+		respWriter.WriteHeader(status)
+	}
+	t, err := r.TemplateLookup(name, templateCtx)
+	if err != nil {
+		return texttemplate.ExecError{Name: name, Err: err}
+	}
+	return t.Execute(w, data)
+}
+
+var PageRenderer = sync.OnceValue(func() *pageRenderer {
+	rendererType := util.Iif(setting.IsProd, "static", "auto-reloading")
+	log.Debug("Creating %s HTML Renderer", rendererType)
+
+	assetFS := AssetFS()
+	tr := &tmplRender{
+		collectTemplateNames: func() ([]string, error) {
+			names, err := assetFS.ListAllFiles(".", true)
+			if err != nil {
+				return nil, err
+			}
+			names = slices.DeleteFunc(names, func(file string) bool {
+				return strings.HasPrefix(file, "mail/") || !strings.HasSuffix(file, ".tmpl")
+			})
+			for i, file := range names {
+				names[i] = strings.TrimSuffix(file, ".tmpl")
+			}
+			return names, nil
+		},
+		readTemplateContent: func(name string) ([]byte, error) {
+			return assetFS.ReadFile(name + ".tmpl")
+		},
+	}
+
+	pr := &pageRenderer{tmplRenderer: tr}
+	if err := tr.recompileTemplates(pr.funcMapDummy()); err != nil {
+		processStartupTemplateError(err)
+	}
+
+	if !setting.IsProd {
+		go AssetFS().WatchLocalChanges(graceful.GetManager().ShutdownContext(), func() {
+			if err := tr.recompileTemplates(pr.funcMapDummy()); err != nil {
+				log.Error("Template error: %v\n%s", err, log.Stack(2))
+			}
+		})
+	}
+	return pr
+})
+
+func PageRendererReload() error {
+	return PageRenderer().tmplRenderer.recompileTemplates(PageRenderer().funcMapDummy())
+}