Replace WidgetGenerator sample with NStack sample

- Generates a NStack instance
- Generate bundled translations

build.yaml

@@ -1,20 +1,9 @@
 # Read about `build.yaml` at https://pub.dartlang.org/packages/build_config
-targets:
-  $default:
-    builders:
-      freezed:
-        enabled: true
-        generate_for:
-          exclude:
-            - test
-            - example
-          include:
-            - test
 
 builders:
-  jsonWidgetBuilder:
-    import: "package:nstack/json_widget.dart"
-    builder_factories: ["jsonWidgetBuilder"]
+  nstackBuilder:
+    import: "package:nstack/builder.dart"
+    builder_factories: ["nstackBuilder"]
     build_extensions: {".json": [".dart"]}
     build_to: source
     auto_apply: dependents

example/lib/main.dart

@@ -3,6 +3,7 @@ import 'dart:async';
 
 import 'package:flutter/services.dart';
 import 'package:nstack/nstack.dart';
+import 'nstack.dart';
 
 void main() {
   runApp(MyApp());
@@ -27,7 +28,7 @@ class _MyAppState extends State<MyApp> {
     String platformVersion;
     // Platform messages may fail, so we use a try/catch PlatformException.
     try {
-      platformVersion = await Nstack.platformVersion;
+      platformVersion = await NStack.platformVersion;
     } on PlatformException {
       platformVersion = 'Failed to get platform version.';
     }

example/lib/nstack.json

@@ -0,0 +1,4 @@
+{
+  "nstack_project_id": "123123123",
+  "nstack_api_key": "abcabcabc"
+}

lib/builder.dart

@@ -0,0 +1,5 @@
+import 'package:build/build.dart';
+import 'package:nstack/src/nstack_builder.dart';
+
+/// Creates a [NstackBuilder]
+Builder nstackBuilder(BuilderOptions builderOptions) => const NstackBuilder();

lib/nstack.dart

@@ -2,9 +2,24 @@ import 'dart:async';
 
 import 'package:flutter/services.dart';
 
-class Nstack {
-  static const MethodChannel _channel =
-      const MethodChannel('nstack');
+class NStack {
+  final String _projectId;
+  final String _apiKey;
+  final Map<String, String> _bundledTranslations;
+
+  NStack._(this._projectId, this._apiKey, this._bundledTranslations);
+
+  static NStack _instance;
+
+  static NStack instance(String projectId, String apiKey,
+      Map<String, String> bundledTranslations) {
+    if (_instance == null) {
+      _instance = NStack._(projectId, apiKey, bundledTranslations);
+    }
+    return _instance;
+  }
+
+  static const MethodChannel _channel = const MethodChannel('nstack');
 
   static Future<String> get platformVersion async {
     final String version = await _channel.invokeMethod('getPlatformVersion');

lib/src/nstack_builder.dart

@@ -0,0 +1,43 @@
+import 'dart:async';
+import 'dart:convert';
+
+import 'package:build/build.dart';
+
+/// A builder which outputs widgets from json.
+class NstackBuilder implements Builder {
+  const NstackBuilder();
+
+  @override
+  FutureOr<void> build(BuildStep buildStep) async {
+    /// Read the input source and parse it as JSON.
+    Map<String, Object> input;
+    String rojectId;
+    String apiKey;
+    final AssetId outputId = buildStep.inputId.changeExtension('.dart');
+    try {
+      input = json.decode(await buildStep.readAsString(buildStep.inputId));
+      rojectId = input["nstack_project_id"]; // TODO: Validate.
+      apiKey = input["nstack_api_key"]; // TODO: Validate.
+    } catch (err) {
+      // TODO: Inform SDK user about error.
+    }
+    final StringBuffer output = StringBuffer();
+    output.writeln("// Generated by NStack, do not modify this file.");
+    output.writeln("import 'package:nstack/nstack.dart';");
+    output.writeln("");
+    output.writeln("final NStack nstack = NStack.instance(\"$rojectId\", \"$apiKey\", _bundledTranslations);");
+    output.writeln("");
+    output.writeln('''
+final _bundledTranslations = {
+  'en_EN':'{"data":{"section1":{"key1":"value80493753","key2":"value2"}},"meta":{"language":{"id":56,"name":"English","locale":"en_EN","direction":"LRM","is_default":false,"is_best_fit":false},"platform":{"id":447,"slug":"mobile"}}}',
+  'fr-BE': '{"data":{"section1":{"key1":"valeur1","key2":"valeur2"}},"meta":{"language":{"id":54,"name":"French (Belgian)","locale":"fr-BE","direction":"LRM","is_default":false,"is_best_fit":false},"platform":{"id":447,"slug":"mobile"}}}',
+};
+''');
+    await buildStep.writeAsString(outputId, output.toString());
+  }
+
+  @override
+  Map<String, List<String>> get buildExtensions => const {
+        '.json': ['.dart']
+      };
+}

test/nstack_test.dart

@@ -18,6 +18,6 @@ void main() {
   });
 
   test('getPlatformVersion', () async {
-    expect(await Nstack.platformVersion, '42');
+    expect(await NStack.platformVersion, '42');
   });
 }