add callbacks to setLanguage

- adds optional success and failure callbacks to setting language

Author: nan-li

android/src/main/java/com/geektime/rnonesignalandroid/RNOneSignal.java

@@ -288,8 +288,38 @@ public void getDeviceState(Promise promise) {
    }
 
    @ReactMethod
-   public void setLanguage(String language) {
-      OneSignal.setLanguage(language);
+   public void setLanguage(String language, final Callback successCallback, final Callback failureCallback) {
+      OneSignal.setLanguage(language, new OneSignal.OSSetLanguageCompletionHandler() {
+         final Callback[] callbackArr = new Callback[]{ successCallback, failureCallback };
+         @Override
+         public void onSuccess(String results) {
+            if (callbackArr[0] != null) {
+               if (results == null) {
+                  results = "{'success' : 'true', 'message' : 'Successfully set language.'}";
+               }
+               callbackArr[0].invoke(results);
+               callbackArr[0] = null;
+               callbackArr[1] = null; // prevent other callback from being invoked by another channel
+            }
+         }
+
+         @Override
+         public void onFailure(OneSignal.OSLanguageError error) {
+            try {
+               if (callbackArr[1] != null) {
+                  String errorMessage = error.getMessage();
+                  if (errorMessage == null) {
+                     errorMessage = "Failed to set language.";
+                  }
+                  callbackArr[1].invoke(RNUtils.jsonToWritableMap(jsonFromErrorMessageString(errorMessage)));
+                  callbackArr[0] = null;
+                  callbackArr[1] = null;
+               }
+            } catch (JSONException exception) {
+               exception.printStackTrace();
+            }
+         }
+      });
    }
 
    @ReactMethod

ios/RCTOneSignal/RCTOneSignalEventEmitter.m

@@ -245,8 +245,12 @@ + (void)sendEventWithName:(NSString *)name withBody:(NSDictionary *)body {
     }
 }
 
-RCT_EXPORT_METHOD(setLanguage:(NSString *)language) {
-    [OneSignal setLanguage:language];
+RCT_EXPORT_METHOD(setLanguage:(NSString *)language successCallback:(RCTResponseSenderBlock)successCallback failureCallback:(RCTResponseSenderBlock)failureCallback) {
+    [OneSignal setLanguage:language withSuccess:^(NSDictionary *success) {
+        successCallback(@[success]);
+    } withFailure:^(NSError *error) {
+        failureCallback([self processNSError:error]);
+    }];
 }
 
 RCT_EXPORT_METHOD(setNotificationOpenedHandler) {

src/index.ts

@@ -287,12 +287,21 @@ export default class OneSignal {
     /**
      * Allows you to set the app defined language with the OneSignal SDK.
      * @param  {string} language
+     * @param  {(success:object) => void} onSuccess
+     * @param  {(failure:object) => void} onFailure
      * @returns void
      */
-    static setLanguage(language: string): void {
+     static setLanguage(language: string, onSuccess?: (success: object) => void, onFailure?: (failure: object) => void): void {
         if (!isNativeModuleLoaded(RNOneSignal)) return;
 
-        RNOneSignal.setLanguage(language);
+        if (!onSuccess) {
+            onSuccess = function(){};
+        }
+
+        if (!onFailure) {
+            onFailure = function(){};
+        }
+        RNOneSignal.setLanguage(language, onSuccess, onFailure);
     }
 
     /* T A G S */