Adding mediaFileWithTransform

Author: mmathewsTableau

README.md

@@ -696,6 +696,14 @@ await ReactNativeBlobUtil.MediaCollection.writeToMediafile('content://....', //
 );
 ````
 
+Copies and tranforms data from a file in the apps storage to an existing entry of the Media Store. NOTE: you must set a transformer on the file in order for the transformation to happen (see [Setting a File Transformer](#Setting-A-File-Transformer)).
+
+````js
+await ReactNativeBlobUtil.MediaCollection.writeToMediafileWithTransform('content://....', // content uri of the entry in the media storage
+        localpath // path to the file that should be copied
+);
+````
+
 #### copyToInternal
 Copies an entry form the media storage to the apps internal storage.
 ````js

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

@@ -438,8 +438,8 @@ public void createMediaFile(ReadableMap filedata, String mt, Promise promise) {
     }
 
     @ReactMethod
-    public void writeToMediaFile(String fileUri, String path, Promise promise) {
-        boolean res = ReactNativeBlobUtilMediaCollection.writeToMediaFile(Uri.parse(fileUri), path, promise);
+    public void writeToMediaFile(String fileUri, String path, boolean transformFile, Promise promise) {
+        boolean res = ReactNativeBlobUtilMediaCollection.writeToMediaFile(Uri.parse(fileUri), path, transformFile, promise);
         if(res) promise.resolve("Success");
     }
 
@@ -478,7 +478,7 @@ public void copyToMediaStore(ReadableMap filedata, String mt, String path, Promi
             return;
         }
 
-        boolean res = ReactNativeBlobUtilMediaCollection.writeToMediaFile(fileuri, path, promise);
+        boolean res = ReactNativeBlobUtilMediaCollection.writeToMediaFile(fileuri, path, false, promise);
         if(res) promise.resolve(fileuri.toString());
     }
 

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

@@ -124,7 +124,7 @@ public static Uri createNewMediaFile(FileDescription file, MediaType mt, ReactAp
         return null;
     }
 
-    public static boolean writeToMediaFile(Uri fileUri, String data, Promise promise) {
+    public static boolean writeToMediaFile(Uri fileUri, String data, boolean transformFile, Promise promise) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
             try {
                 Context appCtx = ReactNativeBlobUtil.RCTContext.getApplicationContext();
@@ -151,16 +151,31 @@ public static boolean writeToMediaFile(Uri fileUri, String data, Promise promise
                             promise.reject("ENOENT", "No such file ('" + normalizedData + "')");
                             return false;
                         }
-                        byte[] buf = new byte[10240];
-                        int read;
+
 
                         FileInputStream fin = new FileInputStream(src);
                         FileOutputStream out = new FileOutputStream(descr.getFileDescriptor());
 
-                        while ((read = fin.read(buf)) > 0) {
-                            out.write(buf, 0, read);
+                        if (transformFile) {
+                            // in order to transform file, we must load the entire file onto memory
+                            int length = (int) src.length();
+                            byte[] bytes = new byte[length];
+                            fin.read(bytes);
+                            if (ReactNativeBlobUtilFileTransformer.sharedFileTransformer == null) {
+                                throw new IllegalStateException("Write to media file with transform was specified but the shared file transformer is not set");
+                            }
+                            byte[] transformedBytes = ReactNativeBlobUtilFileTransformer.sharedFileTransformer.onWriteFile(bytes);
+                            out.write(transformedBytes);
+                        } else  {
+                            byte[] buf = new byte[10240];
+                            int read;
+
+                            while ((read = fin.read(buf)) > 0) {
+                                out.write(buf, 0, read);
+                            }
                         }
 
+
                         fin.close();
                         out.close();
                         descr.close();

index.d.ts

@@ -830,6 +830,13 @@ export interface MediaCollection {
      */
     writeToMediafile(uri: string, path: string): Promise<string>
 
+    /**
+     * Copies and transforms an existing file to a mediastore file. Make sure FileTransformer is set
+     * @param uri URI of the destination mediastore file
+     * @param path Path to the existing file which should be copied
+     */
+    writeToMediafileWithTransform(uri: string, path: string): Promise<string>
+
     /**
      * Copies a file from the mediastore to the apps internal storage
      * @param contenturi URI of the mediastore file

mediacollection.js

@@ -9,7 +9,11 @@ function createMediafile(fd: filedescriptor, mediatype: string): Promise {
 }
 
 function writeToMediafile(uri: string, path: string) {
-    return ReactNativeBlobUtil.writeToMediaFile(uri, path);
+    return ReactNativeBlobUtil.writeToMediaFile(uri, path, false);
+}
+
+function writeToMediafileWithTransform(uri: string, path: string) {
+    return ReactNativeBlobUtil.writeToMediaFile(uri, path, true);
 }
 
 function copyToInternal(contenturi: string, destpath: string) {