feat(gnoweb): "No render" page/component

examples/gno.land/r/docs/docs.gno

@@ -14,6 +14,7 @@ Explore various examples to learn more about Gno functionality and usage.
 - [Buttons](/r/docs/buttons) - Add buttons to your realm's render.
 - [AVL Pager](/r/docs/avl_pager) - Paginate through AVL tree items.  
 - [Img Embed](/r/docs/img_embed) - Demonstrates how to embed an image.
+- [Optional Render](/r/docs/optional_render) - Render() is optional in realms.
 - ...
 <!-- meta issue with suggestions: https://github.com/gnolang/gno/issues/3292 -->
 

examples/gno.land/r/docs/optional_render/gno.mod

@@ -0,0 +1 @@
+module gno.land/r/docs/optional_render

examples/gno.land/r/docs/optional_render/optional_render.gno

@@ -0,0 +1,7 @@
+package optional_render
+
+func Info() string {
+	return `Having a Render() function in your realm is optional!
+If you do decide to have a Render() function, it must have the following signature:
+func Render(path string) string { ... }`
+}

gno.land/pkg/gnoweb/app_test.go

@@ -47,6 +47,7 @@ func TestRoutes(t *testing.T) {
 		{"/game-of-realms", found, "/contribute"},
 		{"/gor", found, "/contribute"},
 		{"/blog", found, "/r/gnoland/blog"},
+		{"/r/docs/optional_render", ok, "No Render"},
 		{"/r/not/found/", notFound, ""},
 		{"/404/not/found", notFound, ""},
 		{"/아스키문자가아닌경로", notFound, ""},

gno.land/pkg/gnoweb/components/view_status.go

@@ -2,10 +2,38 @@ package components
 
 const StatusViewType ViewType = "status-view"
 
+// StatusData holds the dynamic fields for the "status" template
 type StatusData struct {
-	Message string
+	Title      string
+	Body       string
+	ButtonURL  string
+	ButtonText string
 }
 
-func StatusComponent(message string) *View {
-	return NewTemplateView(StatusViewType, "status", StatusData{message})
+// StatusErrorComponent returns a view for error scenarios
+func StatusErrorComponent(message string) *View {
+	return NewTemplateView(
+		StatusViewType,
+		"status",
+		StatusData{
+			Title:      "Error: " + message,
+			Body:       "Something went wrong.",
+			ButtonURL:  "/",
+			ButtonText: "Go Back Home",
+		},
+	)
+}
+
+// StatusNoRenderComponent returns a view for non-error notifications
+func StatusNoRenderComponent(pkgPath string) *View {
+	return NewTemplateView(
+		StatusViewType,
+		"status",
+		StatusData{
+			Title:      "No Render",
+			Body:       "This realm does not implement a Render() function.",
+			ButtonURL:  pkgPath + "$source",
+			ButtonText: "View Realm Source",
+		},
+	)
 }

gno.land/pkg/gnoweb/components/views/status.html

@@ -1,8 +1,12 @@
 {{ define "status" }}
 <div class="col-span-10 flex flex-col h-full w-full mt-10 pb-24 justify-center items-center">
   <img src="/public/imgs/gnoland.svg" alt="gno land" width="70px" height="70px" />
-  <h1 class="text-600 font-bold text-gray-600 pb-4 capitalize"><span>Error:</span> <span>{{ .Message }}</span></h1>
-  <p class="pb-3">Something went wrong. Let’s find our way back!</p>
-  <a href="/" class="rounded border py-1 px-2 hover:bg-gray-100">Go Back Home</a>
+  <h1 class="text-600 font-bold text-gray-600 pb-4 capitalize">
+    {{ .Title }}
+  </h1>
+  <p class="pb-3">{{ .Body }}</p>
+  <a href="{{ .ButtonURL }}" class="rounded border py-1 px-2 hover:bg-gray-100">
+    {{ .ButtonText }}
+  </a>
 </div>
 {{ end }}

gno.land/pkg/gnoweb/handler.go

@@ -114,7 +114,7 @@
 	gnourl, err := ParseGnoURL(r.URL)
 	if err != nil {
 		h.Logger.Warn("unable to parse url path", "path", r.URL.Path, "error", err)
-		return http.StatusNotFound, components.StatusComponent("invalid path")
+		return http.StatusNotFound, components.StatusErrorComponent("invalid path")
 	}
 
 	breadcrumb := generateBreadcrumbPaths(gnourl)
@@ -130,7 +130,7 @@
 		return h.GetPackageView(gnourl)
 	default:
 		h.Logger.Debug("invalid path: path is neither a pure package or a realm")
-		return http.StatusBadRequest, components.StatusComponent("invalid path")
+		return http.StatusBadRequest, components.StatusErrorComponent("invalid path")
 	}
 }
 
@@ -160,6 +160,10 @@
 
 	meta, err := h.Client.RenderRealm(&content, gnourl.Path, gnourl.EncodeArgs())
 	if err != nil {
+		if errors.Is(err, ErrRenderNotDeclared) {
+			return http.StatusOK, components.StatusNoRenderComponent(gnourl.Path)
+		}
+
 		h.Logger.Error("unable to render realm", "error", err, "path", gnourl.EncodeURL())
 		return GetClientErrorStatusPage(gnourl, err)
 	}
@@ -223,7 +227,7 @@
 
 	if len(files) == 0 {
 		h.Logger.Debug("no files available", "path", gnourl.Path)
-		return http.StatusOK, components.StatusComponent("no files available")
+		return http.StatusOK, components.StatusErrorComponent("no files available")
 	}
 
 	var fileName string
@@ -266,7 +270,7 @@
 
 	if len(files) == 0 {
 		h.Logger.Debug("no files available", "path", gnourl.Path)
-		return http.StatusOK, components.StatusComponent("no files available")
+		return http.StatusOK, components.StatusErrorComponent("no files available")
 	}
 
 	return http.StatusOK, components.DirectoryView(components.DirData{
@@ -283,13 +287,13 @@
 
 	switch {
 	case errors.Is(err, ErrClientPathNotFound):
-		return http.StatusNotFound, components.StatusComponent(err.Error())
+		return http.StatusNotFound, components.StatusErrorComponent(err.Error())
 	case errors.Is(err, ErrClientBadRequest):
-		return http.StatusInternalServerError, components.StatusComponent("bad request")
+		return http.StatusInternalServerError, components.StatusErrorComponent("bad request")
 	case errors.Is(err, ErrClientResponse):
 		fallthrough // XXX: for now fallback as internal error
 	default:
-		return http.StatusInternalServerError, components.StatusComponent("internal error")
+		return http.StatusInternalServerError, components.StatusErrorComponent("internal error")
 	}
 }
 

gno.land/pkg/gnoweb/webclient.go

@@ -10,6 +10,7 @@ import (
 
 var (
 	ErrClientPathNotFound = errors.New("package not found")
+	ErrRenderNotDeclared  = errors.New("render function not declared")
 	ErrClientBadRequest   = errors.New("bad request")
 	ErrClientResponse     = errors.New("node response error")
 )

gno.land/pkg/gnoweb/webclient_html.go

@@ -177,6 +177,7 @@ func (s *HTMLWebClient) RenderRealm(w io.Writer, pkgPath string, args string) (*
 
 	pkgPath = strings.Trim(pkgPath, "/")
 	data := fmt.Sprintf("%s/%s:%s", s.domain, pkgPath, args)
+
 	rawres, err := s.query(qpath, []byte(data))
 	if err != nil {
 		return nil, err
@@ -213,6 +214,10 @@ func (s *HTMLWebClient) query(qpath string, data []byte) ([]byte, error) {
 			return nil, ErrClientPathNotFound
 		}
 
+		if strings.Contains(err.Error(), "Render not declared") { /// XXX shoud this be a vm error?
+			return nil, ErrRenderNotDeclared
+		}
+
 		s.logger.Error("response error", "path", qpath, "log", qres.Response.Log)
 		return nil, fmt.Errorf("%w: %s", ErrClientResponse, err.Error())
 	}