example. restore readme

example/README.md

@@ -1,16 +1,140 @@
 # appmetrica_sdk_example
 
-A new Flutter project.
+Demonstrates how to use the appmetrica_sdk plugin.
 
-## Getting Started
+### Example code
 
-This project is a starting point for a Flutter application.
+``` dart
+import 'dart:async';
 
-A few resources to get you started if this is your first Flutter project:
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 
-- [Lab: Write your first Flutter app](https://flutter.dev/docs/get-started/codelab)
-- [Cookbook: Useful Flutter samples](https://flutter.dev/docs/cookbook)
+import 'package:appmetrica_sdk/appmetrica_sdk.dart';
 
-For help getting started with Flutter, view our
-[online documentation](https://flutter.dev/docs), which offers tutorials,
-samples, guidance on mobile development, and a full API reference.
+void main() async {
+  WidgetsFlutterBinding.ensureInitialized();
+
+  /// Initializing the AppMetrica SDK.
+  await AppmetricaSdk()
+      .activate(apiKey: 'db2206ed-c61a-43aa-b95c-6912f60bd25e');
+
+  runApp(MyApp());
+}
+
+class MyApp extends StatefulWidget {
+  @override
+  _MyAppState createState() => _MyAppState();
+}
+
+class _MyAppState extends State<MyApp> {
+  String _libraryVersion = 'Unknown';
+
+  @override
+  void initState() {
+    super.initState();
+    initLibrarayVersionState();
+  }
+
+  // Platform messages are asynchronous, so we initialize in an async method.
+  Future<void> initLibrarayVersionState() async {
+    String libraryVersion;
+    // Platform messages may fail, so we use a try/catch PlatformException.
+    try {
+      libraryVersion = await AppmetricaSdk().getLibraryVersion();
+    } on PlatformException {
+      libraryVersion = 'Failed to get library version.';
+    }
+
+    // If the widget was removed from the tree while the asynchronous platform
+    // message was in flight, we want to discard the reply rather than calling
+    // setState to update our non-existent appearance.
+    if (!mounted) {
+      return;
+    }
+
+    setState(() {
+      _libraryVersion = libraryVersion;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialApp(
+        home: Scaffold(
+            appBar: AppBar(
+              title: const Text('Plugin example app'),
+            ),
+            body: Container(
+              padding: const EdgeInsets.all(8),
+              child: Center(
+                child: Column(
+                  children: <Widget>[
+                    Container(
+                      child: Text(
+                          'AppMetrica SDK Library version: $_libraryVersion\n'),
+                    ),
+                    RaisedButton(
+                      child: const Text('Send a custom event'),
+                      onPressed: () {
+                        /// Sending a custom event without nested parameters.
+                        AppmetricaSdk().reportEvent(name: 'Updates installed');
+                      },
+                    ),
+                    RaisedButton(
+                      child: const Text(
+                          'Send a custom event with nested parameters'),
+                      onPressed: () {
+                        /// Sending a custom event with nested parameters.
+                        AppmetricaSdk().reportEvent(
+                            name: 'Current app statistics',
+                            attributes: <String, dynamic>{
+                              'Application': 'com.company.myapp.awesomeapp',
+                              'Audience': 1000000000,
+                              'Product price in €': 10000000.99,
+                              'nested map': <String, dynamic>{
+                                'strategies': 'Age of Empires',
+                              },
+                            });
+                      },
+                    ),
+                    RaisedButton(
+                      child: const Text('Send user profile attributes'),
+                      onPressed: () {
+                        /// Sending profile custom string attribute.
+                        AppmetricaSdk().reportUserProfileCustomString(
+                            key: 'string_attribute', value: 'string');
+
+                        /// Sending profile custom number attribute.
+                        AppmetricaSdk().reportUserProfileCustomNumber(
+                            key: 'number_attribute', value: 55);
+
+                        /// Sending profile custom boolean attribute.
+                        AppmetricaSdk().reportUserProfileCustomBoolean(
+                            key: 'boolean_attribute', value: true);
+
+                        /// Sending profile custom attribute of the counter type.
+                        AppmetricaSdk().reportUserProfileCustomCounter(
+                            key: 'counter_attribute', delta: 1);
+
+                        /// Sets the ID of the user profile. Required for predefined
+                        /// profile attributes like Name or Notifications enabled.
+                        AppmetricaSdk().setUserProfileID(userProfileID: 'id');
+
+                        /// Sending profile predefined user name attribute.
+                        AppmetricaSdk()
+                            .reportUserProfileUserName(userName: 'John');
+
+                        /// Sending profile predefined NotificationsEnabled attribute.
+                        AppmetricaSdk().reportUserProfileNotificationsEnabled(
+                            notificationsEnabled: true);
+                      },
+                    ),
+                  ],
+                ),
+              ),
+            )));
+  }
+}
+
+```