CB-5532 WP8. Add binary data support to FileWriter

Author: sgrebnov

src/wp/File.cs

@@ -799,6 +799,9 @@ public void write(string options)
                     return;
                 }
 
+                char[] dataToWrite = isBinary ? JSON.JsonHelper.Deserialize<char[]>(data) :
+                    data.ToCharArray();
+
                 using (IsolatedStorageFile isoFile = IsolatedStorageFile.GetUserStoreForApplication())
                 {
                     // create the file if not exists
@@ -817,12 +820,12 @@ public void write(string options)
                         using (BinaryWriter writer = new BinaryWriter(stream))
                         {
                             writer.Seek(0, SeekOrigin.End);
-                            writer.Write(data.ToCharArray());
+                            writer.Write(dataToWrite);
                         }
                     }
                 }
 
-                DispatchCommandResult(new PluginResult(PluginResult.Status.OK, data.Length), callbackId);
+                DispatchCommandResult(new PluginResult(PluginResult.Status.OK, dataToWrite.Length), callbackId);
             }
             catch (Exception ex)
             {

www/FileWriter.js

@@ -118,7 +118,11 @@ FileWriter.prototype.write = function(data) {
 
     // Mark data type for safer transport over the binary bridge
     isBinary = supportsBinary && (data instanceof ArrayBuffer);
-
+    if (isBinary) {
+        // create a plain array, using the keys from the Uint8Array view so that we can serialize it
+        data = Array.apply(null, new Uint8Array(data));
+    }
+    
     // Throw an exception if we are already writing a file
     if (this.readyState === FileWriter.WRITING) {
         throw new FileError(FileError.INVALID_STATE_ERR);