Logic to write file content to a media file

Author: Ron Radtke

android/src/main/java/com/ReactNativeBlobUtil/ReactNativeBlobUtil.java

@@ -441,4 +441,9 @@ public void createMediaFile(ReadableMap filedata, String mt, Promise promise) {
         else promise.reject("ReactNativeBlobUtil.createMediaFile", "File could not be created");
     }
 
+    @ReactMethod
+    public void writeToMediaFile(String fileUri, String data, Promise promise){
+        ReactNativeBlobUtilMediaCollection.writeToMediaFile(Uri.parse(fileUri), data, promise);
+    }
+
 }

android/src/main/java/com/ReactNativeBlobUtil/ReactNativeBlobUtilMediaCollection.java

@@ -9,8 +9,11 @@
 import android.provider.MediaStore;
 
 import com.ReactNativeBlobUtil.Utils.FileDescription;
+import com.facebook.react.bridge.Promise;
 
 import java.io.File;
+import java.io.IOException;
+import java.io.OutputStream;
 
 public class ReactNativeBlobUtilMediaCollection {
 
@@ -93,4 +96,28 @@ public static Uri createNewMediaFile(FileDescription file, MediaType mt) {
         return null;
     }
 
+    public static void writeToMediaFile(Uri fileUri, String data, Promise promise) {
+        try {
+            Context appCtx = ReactNativeBlobUtil.RCTContext.getApplicationContext();
+            ContentResolver resolver = appCtx.getContentResolver();
+
+            // set pending
+            ContentValues contentValues = new ContentValues();
+            contentValues.put(MediaStore.MediaColumns.IS_PENDING, 1);
+            resolver.update(fileUri, contentValues, null, null);
+
+            // write data
+            OutputStream outputStream = resolver.openOutputStream(fileUri);
+            outputStream.write(data.getBytes());
+
+            // remove pending
+            contentValues = new ContentValues();
+            contentValues.put(MediaStore.MediaColumns.IS_PENDING, 0);
+            resolver.update(fileUri, contentValues, null, null);
+
+        } catch (IOException e) {
+            promise.reject("ReactNativeBlobUtil.createMediaFile", "Cannot write to file, file might not exist");
+        }
+    }
+
 }

index.d.ts

@@ -775,4 +775,6 @@ export interface MediaCollection {
      * @param mediatype
      */
     createMediafile(filedata: { name: string, parentFolder: string, mimeType: string }, mediatype: Mediatype): Promise<string>;
+
+    writeToMediafile(uri: string, data: string)
 }

mediacollection.js

@@ -8,6 +8,11 @@ function createMediafile(filedata: Object<{ path: string, parentFolder: string,
     return ReactNativeBlobUtil.createMediaFile(filedata, mediatype);
 }
 
+function writeToMediafile(uri:string, data:string){
+    return ReactNativeBlobUtil.writeToMediaFile(uri, data);
+}
+
 export default {
-    createMediafile
+    createMediafile,
+    writeToMediafile
 };