refactor: enhance NativeDownloadModule to support download progress events

Author: YogendraShelke

android/src/main/java/com/mendix/mendixnative/react/download/NativeDownloadModule.kt

@@ -1,13 +1,15 @@
 package com.mendix.mendixnative.react.download
 
 import com.facebook.react.bridge.*
-import com.facebook.react.modules.core.DeviceEventManagerModule.RCTDeviceEventEmitter
 import okhttp3.OkHttpClient
 import java.io.IOException
 import java.net.ConnectException
 import java.util.concurrent.TimeUnit
 
-class NativeDownloadModule(val context: ReactApplicationContext) {
+class NativeDownloadModule(
+  val context: ReactApplicationContext,
+  private val eventEmitter: ((Double, Double) -> Unit)? = null
+) {
   val client = OkHttpClient()
 
   fun download(
@@ -66,30 +68,15 @@ class NativeDownloadModule(val context: ReactApplicationContext) {
         }
       }
     ) { receivedBytes, totalBytes ->
-      postProgressEvent(
-        receivedBytes,
-        totalBytes
-      )
+      eventEmitter?.invoke(receivedBytes, totalBytes)
     }
   }
 
-  private fun postProgressEvent(receivedBytes: Double, totalBytes: Double) {
-    val params = Arguments.createMap()
-    params.putDouble("receivedBytes", receivedBytes)
-    params.putDouble("totalBytes", totalBytes)
-    context
-      .getJSModule(RCTDeviceEventEmitter::class.java)
-      .emit(DOWNLOAD_PROGRESS_EVENT, params)
-  }
-
   companion object {
-    val supportedEvents: Array<String> = arrayOf(DOWNLOAD_PROGRESS_EVENT)
-
     const val TIMEOUT_KEY = "connectionTimeout"
     const val MIME_TYPE_KEY = "mimeType"
     const val TIMEOUT = 10000
 
-    const val DOWNLOAD_PROGRESS_EVENT = "NDM_DOWNLOAD_PROGRESS_EVENT"
     const val ERROR_DOWNLOAD_FAILED = "ERROR_DOWNLOAD_FAILED"
     const val FILE_ALREADY_EXISTS = "FILE_ALREADY_EXISTS"
     const val ERROR_CONNECTION_FAILED = "ERROR_CONNECTION_FAILED"

android/src/main/java/com/mendixnative/download/MxDownloadModule.kt

@@ -1,5 +1,6 @@
 package com.mendixnative.download
 
+import com.facebook.react.bridge.Arguments
 import com.facebook.react.bridge.Promise
 import com.facebook.react.bridge.ReactApplicationContext
 import com.facebook.react.bridge.ReadableMap
@@ -11,14 +12,35 @@ import com.mendixnative.NativeMxDownloadSpec
 class MxDownloadModule(reactContext: ReactApplicationContext) :
     NativeMxDownloadSpec(reactContext) {
 
-  private val downloadModule = NativeDownloadModule(reactContext)
+  // Pass event emitter callback to NativeDownloadModule
+  private val downloadModule = NativeDownloadModule(
+    reactContext,
+    eventEmitter = { receivedBytes, totalBytes ->
+      emitOnDownloadProgress(receivedBytes, totalBytes)
+    }
+  )
 
   override fun getName(): String = NAME
 
   override fun download(url: String, downloadPath: String, config: ReadableMap, promise: Promise) {
     downloadModule.download(url, downloadPath, config, promise)
   }
 
+  /**
+  * Emit download progress event.
+  * This matches the codegen pattern: readonly onDownloadProgress: EventEmitter<DownloadProgress>
+  * Codegen generates the base addListener/removeListeners methods automatically.
+  */
+  private fun emitOnDownloadProgress(receivedBytes: Double, totalBytes: Double) {
+    val params = Arguments.createMap().apply {
+      putDouble("receivedBytes", receivedBytes)
+      putDouble("totalBytes", totalBytes)
+    }
+    // Emit via the codegen-generated event emitter
+    // Event name matches the spec: onDownloadProgress
+    emitOnDownloadProgress(params)
+  }
+
   companion object {
     const val NAME = "MxDownload"
   }

ios/TurboModules/MxDownload/MxDownload.mm

@@ -26,7 +26,11 @@ - (void)download:(nonnull NSString *)url
         connectionTimeout = @(config.connectionTimeout().value());
     }    
     NSString *mimeType = config.mimeType();;
-    [[[NativeDownloadModule alloc] init] download:url downloadPath:downloadPath connectionTimeout:connectionTimeout mimeType:mimeType onProgress:nil promise:promise];
+    NativeDownloadModule *downloader = [[NativeDownloadModule alloc] init];
+    [downloader download:url downloadPath:downloadPath connectionTimeout:connectionTimeout mimeType:mimeType onProgress:^(NSDictionary* progress) {
+//        Uncomment the line below to track progress events.
+//        [self emitOnDownloadProgress: progress];
+    } promise:promise];
 }
 
 @end

src/download-handler/NativeMxDownload.ts

@@ -6,14 +6,22 @@ type DownloadConfig = {
   mimeType?: string;
 };
 
+type DownloadProgress = {
+  receivedBytes: CodegenTypes.Double;
+  totalBytes: CodegenTypes.Double;
+};
+
 export interface Spec extends TurboModule {
   download(
     url: string,
     downloadPath: string,
     config: DownloadConfig
   ): Promise<void>;
+
+  // Event emitter for download progress
+  readonly onDownloadProgress: CodegenTypes.EventEmitter<DownloadProgress>;
 }
 
 export default TurboModuleRegistry.getEnforcing<Spec>('MxDownload');
 
-export type { DownloadConfig };
+export type { DownloadConfig, DownloadProgress };