w/ TemplateRenderable

render_container_test.go

@@ -33,14 +33,12 @@ func tplWithRealSlotFunc(ctx context.Context, tpl *template.Template, slots map[
 }
 
 func (v ContainerView) RenderToHTML(ctx context.Context) (template.HTML, error) {
-	return RenderToHTML(tplWithRealSlotFunc(
-		ctx,
-		containerViewTpl,
-		map[string]AsRenderable{
+	return TemplateRenderable{
+		Tpl: tplWithRealSlotFunc(ctx, containerViewTpl, map[string]AsRenderable{
 			"heading": v.Heading,
 			"body":    v.Body,
-		},
-	), nil)
+		}),
+	}.RenderToHTML(ctx)
 }
 
 func (v ContainerView) Renderable(_ context.Context) (Renderable, error) {

renderer.go

@@ -7,33 +7,55 @@ import (
 	"html/template"
 )
 
-func Render(ctx context.Context, r AsRenderable) (template.HTML, error) {
+func RenderToHTML(ctx context.Context, r Renderable, errHandler any) (template.HTML, error) {
+	var empty template.HTML
+
 	if r == nil {
-		return template.HTML(""), nil
+		return empty, nil
+	}
+
+	out, err := r.RenderToHTML(ctx)
+	if err != nil {
+		return handleRenderError(ctx, err, errHandler)
+	}
+
+	return out, nil
+}
+
+func Render(ctx context.Context, v AsRenderable) (template.HTML, error) {
+	var empty template.HTML
+
+	if v == nil {
+		return empty, nil
 	}
 
-	renderable, err := r.Renderable(ctx)
+	r, err := v.Renderable(ctx)
 	if err != nil {
-		return handleRenderError(ctx, err, r)
+		return handleRenderError(ctx, err, v)
 	}
 
-	out, err := renderable.RenderToHTML(ctx)
+	out, err := RenderToHTML(ctx, r, v)
 	if err != nil {
-		return handleRenderError(ctx, err, r)
+		return empty, err
 	}
 
 	return out, nil
 }
 
-func RenderToHTML(tpl *template.Template, data any) (template.HTML, error) {
+type TemplateRenderable struct {
+	Tpl  *template.Template
+	Data any
+}
+
+func (v TemplateRenderable) RenderToHTML(_ context.Context) (template.HTML, error) {
 	var empty template.HTML
 
-	if tpl == nil {
+	if v.Tpl == nil {
 		return empty, fmt.Errorf("missing template")
 	}
 
 	var bs bytes.Buffer
-	if err := tpl.Execute(&bs, data); err != nil {
+	if err := v.Tpl.Execute(&bs, v.Data); err != nil {
 		return empty, fmt.Errorf("tpl.Execute(): %w", err)
 	}
 

view.go

@@ -13,15 +13,13 @@ type View struct {
 }
 
 func (v View) RenderToHTML(ctx context.Context) (template.HTML, error) {
-	tpl := v.Tpl
-	if v.Tpl != nil {
-		tpl = v.Slots.addToTemplate(ctx, v.Tpl)
-	}
-
-	return RenderToHTML(tpl, v.Data)
+	return TemplateRenderable{
+		Tpl:  v.Slots.addToTemplate(ctx, v.Tpl),
+		Data: v.Data,
+	}.RenderToHTML(ctx)
 }
 
-func (v View) Renderable(_ context.Context) (Renderable, error) {
+func (v View) Renderable(ctx context.Context) (Renderable, error) {
 	return v, nil
 }