add standalone option

packages/jaspr/CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Added `table` and related html methods.
 - Added `value` parameter to `select()` method.
+- Add 'standalone' option to `renderComponent` method.
 
 ## 0.16.2
 

packages/jaspr/lib/src/server/adapters/client_script_adapter.dart

@@ -10,9 +10,9 @@ class ClientScriptAdapter extends HeadScopeAdapter {
   final List<ClientTarget> clientTargets;
 
   @override
-  void applyHead(MarkupRenderObject head) {
+  bool applyHead(MarkupRenderObject head) {
     if (clientTargets.isEmpty) {
-      return;
+      return false;
     }
 
     String source;
@@ -27,5 +27,7 @@ class ClientScriptAdapter extends HeadScopeAdapter {
       head.createChildRenderObject()
         ..updateElement('script', null, null, null, {'src': '$source.dart.js', 'defer': ''}, null),
     );
+
+    return true;
   }
 }

packages/jaspr/lib/src/server/adapters/global_styles_adapter.dart

@@ -6,16 +6,18 @@ class GlobalStylesAdapter extends HeadScopeAdapter {
   final ServerAppBinding binding;
 
   @override
-  void applyHead(MarkupRenderObject head) {
+  bool applyHead(MarkupRenderObject head) {
     var styles = binding.options.styles?.call() ?? [];
     if (styles.isEmpty) {
-      return;
+      return false;
     }
 
     head.children.insertBefore(
       head.createChildRenderObject()
         ..updateElement('style', null, null, null, null, null)
         ..children.insertBefore(head.createChildRenderObject()..updateText(styles.render(), true)),
     );
+
+    return true;
   }
 }

packages/jaspr/lib/src/server/adapters/head_scope_adapter.dart

@@ -10,12 +10,17 @@ abstract class HeadScopeAdapter extends RenderAdapter {
     var html = root.children.findWhere((c) => c.tag == 'html')?.node ?? root;
     var head = html.children.findWhere((c) => c.tag == 'head')?.node;
 
+    bool needsInsert = false;
     if (head == null) {
-      html.children.insertAfter(head = html.createChildRenderObject()..tag = 'head');
+      head = html.createChildRenderObject()..tag = 'head';
+      needsInsert = true;
     }
 
-    applyHead(head);
+    var didApply = applyHead(head);
+    if (didApply && needsInsert) {
+      html.children.insertAfter(head);
+    }
   }
 
-  void applyHead(MarkupRenderObject head);
+  bool applyHead(MarkupRenderObject head);
 }

packages/jaspr/lib/src/server/render_functions.dart

@@ -10,13 +10,13 @@ typedef FileLoader = Future<String?> Function(String);
 /// Performs the rendering process and provides the created [AppBinding] to [setup].
 ///
 /// If [Jaspr.useIsolates] is true, this spawns an isolate for each render.
-Future<String> render(SetupFunction setup, Uri requestUri, FileLoader loadFile) async {
+Future<String> render(SetupFunction setup, Uri requestUri, FileLoader loadFile, bool standalone) async {
   if (!Jaspr.useIsolates) {
     var binding = ServerAppBinding()
       ..setCurrentUri(requestUri)
       ..setFileHandler(loadFile);
     setup(binding);
-    return binding.render();
+    return binding.render(standalone: standalone);
   }
 
   var resultCompleter = Completer<String>.sync();
@@ -38,7 +38,7 @@ Future<String> render(SetupFunction setup, Uri requestUri, FileLoader loadFile)
   });
 
   try {
-    var message = _RenderMessage(setup, requestUri, port.sendPort);
+    var message = _RenderMessage(setup, requestUri, standalone, port.sendPort);
     await Isolate.spawn(_render, message, onError: errorPort.sendPort);
 
     return await resultCompleter.future;
@@ -62,16 +62,17 @@ void _render(_RenderMessage message) async {
     });
   message.setup(binding);
 
-  var result = await binding.render();
+  var result = await binding.render(standalone: message.standalone);
   message.sendPort.send(result);
 }
 
 class _RenderMessage {
   final SetupFunction setup;
   final Uri requestUri;
+  final bool standalone;
   final SendPort sendPort;
 
-  _RenderMessage(this.setup, this.requestUri, this.sendPort);
+  _RenderMessage(this.setup, this.requestUri, this.standalone, this.sendPort);
 }
 
 class _LoadFileRequest {

packages/jaspr/lib/src/server/run_app.dart

@@ -29,14 +29,16 @@ Handler serveApp(AppHandler handler) {
 typedef RenderFunction = FutureOr<Response> Function(Component);
 typedef AppHandler = FutureOr<Response> Function(Request, RenderFunction render);
 
-/// Directly renders the provided component into a html string
-Future<String> renderComponent(Component app) async {
+/// Directly renders the provided component into a html string.
+///
+/// When [standalone] is false (default), the html output will have a full document structure (html, head, body).
+Future<String> renderComponent(Component app, {bool standalone = false}) async {
   _checkInitialized('renderComponent');
   var fileHandler = staticFileHandler();
   return render(_createSetup(app), Uri.parse('https://0.0.0.0/'), (name) async {
     var response = await fileHandler(Request('get', Uri.parse('https://0.0.0.0/$name')));
     return response.statusCode == 200 ? response.readAsString() : null;
-  });
+  }, standalone);
 }
 
 void _checkInitialized(String method) {

packages/jaspr/lib/src/server/server_binding.dart

@@ -25,7 +25,7 @@ class ServerAppBinding extends AppBinding with ComponentsBinding {
     super.attachRootComponent(ClientComponentRegistry(child: app));
   }
 
-  Future<String> render() async {
+  Future<String> render({bool standalone = false}) async {
     if (rootElement == null) return '';
 
     if (rootElement!.owner.isFirstBuild) {
@@ -38,7 +38,7 @@ class ServerAppBinding extends AppBinding with ComponentsBinding {
     var adapters = [
       ..._adapters.reversed,
       GlobalStylesAdapter(this),
-      DocumentAdapter(),
+      if (!standalone) DocumentAdapter(),
     ];
 
     for (var adapter in adapters.reversed) {

packages/jaspr/lib/src/server/server_handler.dart

@@ -86,7 +86,7 @@ Handler createHandler(SetupHandler handle, {http.Client? client, Handler? fileHa
       }
 
       return Response.ok(
-        await render(setup, requestUri, fileLoader),
+        await render(setup, requestUri, fileLoader, false),
         headers: {'Content-Type': 'text/html'},
       );
     });

packages/jaspr/test/server/render_test.dart

@@ -0,0 +1,28 @@
+@TestOn('vm')
+
+import 'package:jaspr/server.dart';
+import 'package:jaspr_test/server_test.dart';
+
+void main() {
+  group('render test', () {
+    setUpAll(() {
+      Jaspr.initializeApp(useIsolates: false);
+    });
+
+    test('renders component with document', () async {
+      var result = await renderComponent(div(id: 'test', []));
+
+      expect(
+          result,
+          equals('<!DOCTYPE html>\n'
+              '<html><head><base href="/"/></head><body><div id="test"></div></body></html>\n'
+              ''));
+    });
+
+    test('renders standalone component', () async {
+      var result = await renderComponent(div(id: 'test', []), standalone: true);
+
+      expect(result, equals('<div id="test"></div>\n'));
+    });
+  });
+}