Add response info to HTTP request so that JS context can get response headers and status

src/android/src/main/java/com/RNFetchBlob/RNFetchBlobReq.java

 
 import com.RNFetchBlob.Response.RNFetchBlobDefaultResp;
 import com.RNFetchBlob.Response.RNFetchBlobFileResp;
+import com.facebook.react.bridge.Arguments;
 import com.facebook.react.bridge.Callback;
 import com.facebook.react.bridge.ReactApplicationContext;
 import com.facebook.react.bridge.ReadableArray;
 import com.facebook.react.bridge.ReadableMap;
 import com.facebook.react.bridge.ReadableMapKeySetIterator;
+import com.facebook.react.bridge.WritableMap;
 
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.util.HashMap;
 
 import okhttp3.Call;
+import okhttp3.Headers;
 import okhttp3.Interceptor;
 import okhttp3.MediaType;
 import okhttp3.OkHttpClient;
 import okhttp3.Response;
 import okhttp3.ResponseBody;
 import okhttp3.FormBody;
+import okhttp3.internal.framed.Header;
 
 /**
  * Created by wkh237 on 2016/6/21.
             case KeepInMemory:
                 try {
                     byte [] b = resp.body().bytes();
-                    callback.invoke(null, android.util.Base64.encodeToString(b,Base64.NO_WRAP));
+                    callback.invoke(null, getResponseInfo(resp), android.util.Base64.encodeToString(b,Base64.NO_WRAP));
                 } catch (IOException e) {
                     callback.invoke("RNFetchBlob failed to encode response data to BASE64 string.", null);
                 }
                 } catch (Exception ignored) {
 
                 }
-                callback.invoke(null, this.destPath);
+                callback.invoke(null, getResponseInfo(resp), this.destPath);
                 break;
             default:
                 try {
-                    callback.invoke(null, new String(resp.body().bytes(), "UTF-8"));
+                    callback.invoke(null, getResponseInfo(resp), new String(resp.body().bytes(), "UTF-8"));
                 } catch (IOException e) {
                     callback.invoke("RNFetchBlob failed to encode response data to UTF8 string.", null);
                 }
             taskTable.remove(taskId);
     }
 
+    private WritableMap getResponseInfo(Response resp) {
+        WritableMap info = Arguments.createMap();
+        info.putInt("status", resp.code());
+        info.putString("state", "2");
+        info.putString("taskId", this.taskId);
+        WritableMap headers = Arguments.createMap();
+        for(int i =0;i< resp.headers().size();i++) {
+            headers.putString(resp.headers().name(i), resp.headers().value(i));
+        }
+        info.putMap("headers", headers);
+        Headers h = resp.headers();
+        if(getHeaderIgnoreCases(h, "content-type").equalsIgnoreCase("text/plain"))
+        {
+            info.putString("respType", "text");
+        }
+        else if(getHeaderIgnoreCases(h, "content-type").equalsIgnoreCase("application/json"))
+        {
+            info.putString("respType", "json");
+        }
+        else if(getHeaderIgnoreCases(h, "content-type").length() < 1)
+        {
+            info.putString("respType", "blob");
+        }
+        else
+        {
+            info.putString("respType", "text");
+        }
+        return info;
+    }
+
+    private String getHeaderIgnoreCases(Headers headers, String field) {
+        String val = headers.get(field);
+        if(val != null) return val;
+        return headers.get(field.toLowerCase()) == null ? "" : headers.get(field.toLowerCase());
+    }
+
     /**
      * Build request body by given string
      * @param body Content of request body in UTF8 string format.

src/ios/RNFetchBlobNetwork.m

     NSString * destPath;
     NSOutputStream * writeStream;
     long bodyLength;
+    NSMutableDictionary * respInfo;
 }
 
 @end
 
         if(path != nil)
             destPath = path;
+        else
+            destPath = [RNFetchBlobFS getTempPath:cacheKey withExtension:[self.options valueForKey:CONFIG_FILE_EXT]];
     }
     else
     {
         }
         else
             respType = @"";
+        respInfo = @{
+                     @"taskId": taskId,
+                     @"state": @"2",
+                     @"headers": headers,
+                     @"respType" : respType,
+                     @"status": [NSString stringWithFormat:@"%d", statusCode ]
+                     };
         [self.bridge.eventDispatcher
          sendDeviceEventWithName: EVENT_STATE_CHANGE
-         body:@{
-                @"taskId": taskId,
-                @"state": @"2",
-                @"headers": headers,
-                @"respType" : respType,
-                @"status": [NSString stringWithFormat:@"%d", statusCode ]
-            }
+         body:respInfo
          ];
     }
 
     NSLog([error localizedDescription]);
     self.error = error;
     [[UIApplication sharedApplication] setNetworkActivityIndicatorVisible:NO];
+    
+    NSString * respType = [respInfo valueForKey:@"respType"];
+    
     if(respFile == YES)
     {
         [writeStream close];
-        callback(@[error == nil ? [NSNull null] : [error localizedDescription], destPath]);
+        callback(@[error == nil ? [NSNull null] : [error localizedDescription],
+                   respInfo == nil ? [NSNull null] : respInfo,
+                   destPath
+                   ]);
     }
     // base64 response
     else {
         NSString * res = [[NSString alloc] initWithData:respData encoding:NSUTF8StringEncoding];
-        callback(@[error == nil ? [NSNull null] : [error localizedDescription], [respData base64EncodedStringWithOptions:0]]);
+        callback(@[error == nil ? [NSNull null] : [error localizedDescription],
+                   respInfo == nil ? [NSNull null] : respInfo,
+                   [respData base64EncodedStringWithOptions:0]
+                   ]);
     }
 }