Add app api

assets/init.js

@@ -1310,3 +1310,37 @@ let UI = {
         })
     }
 }
+
+/**
+ * App related apis
+ * @since 1.2.1
+ */
+let APP = {
+    /**
+     * Get the app version
+     * @returns {string} - The app version
+     */
+    get version() {
+        return appVersion // defined in the engine
+    },
+
+    /**
+     * Get current app locale
+     * @returns {string} - The app locale, in the format of [languageCode]_[countryCode]
+     */
+    get locale() {
+        return sendMessage({
+            method: 'getLocale'
+        })
+    },
+
+    /**
+     * Get current running platform
+     * @returns {string} - The platform name, "android", "ios", "windows", "macos", "linux"
+     */
+    get platform() {
+        return sendMessage({
+            method: 'getPlatform'
+        })
+    }
+}

lib/foundation/js_engine.dart

@@ -155,6 +155,10 @@ class JsEngine with _JSEngineApi, JsUiApi {
             return Future.delayed(Duration(milliseconds: message["time"]));
           case "UI":
             return handleUIMessage(Map.from(message));
+          case "getLocale":
+            return "${App.locale.languageCode}-${App.locale.countryCode}";
+          case "getPlatform":
+            return Platform.operatingSystem;
         }
       }
       return null;