Add background session management #115

src/ios/RNFetchBlob/RNFetchBlob.h

 @property (nonatomic) UIDocumentInteractionController * documentController;
 
 + (RCTBridge *)getRCTBridge;
++ (void) checkExpiredSessions;
 
 @end
 

src/ios/RNFetchBlob/RNFetchBlob.m

         [[NSFileManager defaultManager] createDirectoryAtPath:[RNFetchBlobFS getTempPath] withIntermediateDirectories:YES attributes:nil error:NULL];
     }
     bridgeRef = _bridge;
-    [RNFetchBlobNetwork getExpiredTasks];
+    [RNFetchBlobNetwork emitExpiredTasks];
     return self;
 }
 

src/ios/RNFetchBlobNetwork.h

 //  Copyright © 2016 wkh237. All rights reserved.
 //
 
-#ifndef RNFetchBlobResp_h
-#define RNFetchBlobResp_h
+#ifndef RNFetchBlobNetwork_h
+#define RNFetchBlobNetwork_h
 
 #import <Foundation/Foundation.h>
 #import "RCTBridgeModule.h"
 + (void) cancelRequest:(NSString *)taskId;
 + (void) enableProgressReport:(NSString *) taskId;
 + (void) enableUploadProgress:(NSString *) taskId;
-+ (void) getExpiredTasks;
++ (void) emitExpiredTasks;
 
 - (nullable id) init;
 - (void) sendRequest;
 @end
 
 
-#endif /* RNFetchBlobResp_h */
+#endif /* RNFetchBlobNetwork_h */

src/ios/RNFetchBlobNetwork.m

 
     // #115 handling task expired when application entering backgound for a long time
     [app beginBackgroundTaskWithName:taskId expirationHandler:^{
-        NSLog([NSString stringWithFormat:@"session %@ expired event emit", taskId ]);
+        NSLog([NSString stringWithFormat:@"session %@ expired", taskId ]);
         [expirationTable setObject:task forKey:taskId];
         [app endBackgroundTask:task];
 
 }
 
 // #115 Invoke fetch.expire event on those expired requests so that the expired event can be handled
-+ (void) getExpiredTasks
++ (void) emitExpiredTasks
 {
     NSEnumerator * emu =  [expirationTable keyEnumerator];
     NSString * key;
         NSData * args = @{ @"taskId": key };
         [bridge.eventDispatcher sendDeviceEventWithName:EVENT_EXPIRE body:args];
     }
+    
+    // emit expired event once
+    [expirationTable removeAllObjects];
 }
 
 ////////////////////////////////////////