warn the user if they try to launch without a renderer selected

packages/dioxus/build.rs

@@ -0,0 +1,47 @@
+fn main() {
+	// Warn the user if they enabled the launch feature without any renderers
+    if feature_enabled("launch") {
+		let liveview_renderers = [
+			"liveview",
+			"axum",
+			"salvo",
+			"warp",
+			"rocket",
+		];
+		let fullstack_renderers = [
+			"axum",
+			"salvo",
+			"warp",
+		];
+		let client_renderers = [
+			"desktop",
+			"mobile",
+			"web",
+			"tui",
+		];
+		let client_renderer_selected = client_renderers.iter().any(|renderer| feature_enabled(renderer));
+		if feature_enabled("fullstack") {
+			let server_fullstack_enabled = fullstack_renderers.iter().any(|renderer| feature_enabled(renderer));
+			if !server_fullstack_enabled && !client_renderer_selected {
+				println!("cargo:warning=You have enabled the launch and fullstack features, but have not enabled any renderers. The application will not be able to launch. Try enabling one of the following renderers: {} for the server or one of the following renderers: {} for the client.", fullstack_renderers.join(", "), client_renderers.join(", "));
+			}
+		}
+
+		if feature_enabled("liveview") {
+			let server_selected = liveview_renderers.iter().any(|renderer| feature_enabled(renderer));
+			if !server_selected {
+				println!("cargo:warning=You have enabled the launch and liveview features, but have not enabled any liveview renderers. The application will not be able to launch. Try enabling one of the following renderers: {}", liveview_renderers.join(", "));
+			}
+		}
+
+		if !client_renderer_selected {
+			println!("cargo:warning=You have enabled the launch feature, but have not enabled any client renderers. The application will not be able to launch. Try enabling one of the following renderers: {}, fullstack or liveview", client_renderers.join(", "));
+		}
+    }
+}
+
+fn feature_enabled(feature: &str) -> bool {
+	let feature = "CARGO_FEATURE_".to_owned() + &feature.to_uppercase().replace("-", "_");
+	println!("cargo:rerun-if-env-changed={}", feature);
+	std::env::var(feature).is_ok()
+}