PWA manifest: allow custom start_url (#1094)

Co-authored-by: Maxence Charriere <charriere@outlook.com>

Author: mira-x

pkg/app/http.go

@@ -124,6 +124,11 @@ type Handler struct {
 	// paths prefixed with "/web/". Defaults to app.LocalDir("").
 	Resources ResourceResolver
 
+	// StartURL is the URL opened by default when the installed PWA is opened.
+	// This, however, does not affect the default URL when the app is opened
+	// as normal website in the browser. Defaults to "/".
+	StartURL string
+
 	// Version defines the app's version. It's crucial for determining if an
 	// update is available. Must be set in live environments to avoid recurring
 	// updates. Auto-generated by default for local development updates.
@@ -408,7 +413,7 @@ func (h *Handler) makeManifestJSON() []byte {
 		Name:            h.Name,
 		Description:     h.Description,
 		Scope:           "/",
-		StartURL:        h.Resources.Resolve("/"),
+		StartURL:        h.Resources.Resolve(h.StartURL),
 		BackgroundColor: h.BackgroundColor,
 		ThemeColor:      h.ThemeColor,
 		Display:         "standalone",