title: cache policy not working with php webservice IOS SDK
body: <p>i was using third party api for json response and i was also using <code>cachePolicy:NSURLRequestReturnCacheDataElseLoad</code> for fast response, but now we have developed our own api but now <code>cachePolicy:NSURLRequestReturnCacheDataElseLoad</code> not working, i mean it is not caching the data</p>
  
  <pre><code>NSString *urlAsString = @"api url";
  
  NSString* webStringURL = [urlAsString stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
  NSURL* url = [NSURL URLWithString:webStringURL];
  
  NSURLRequest *urlRequest =
  [NSURLRequest
   requestWithURL:url
   cachePolicy:NSURLRequestReturnCacheDataElseLoad
   timeoutInterval:30.0f];
  
  NSOperationQueue *queue = [[NSOperationQueue alloc] init];
  [NSURLConnection
   sendAsynchronousRequest:urlRequest
   queue:queue
   completionHandler:^(NSURLResponse *response,
                       NSData *data,
                       NSError *error) {
       if ([data length] &gt;0 &amp;&amp; error == nil){          
  
           NSMutableArray *arrayResponse=[NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:&amp;error];
  
          [self prepareData:arrayResponse];
  
  
  
       }
       else if ([data length] == 0 &amp;&amp; error == nil){
           dispatch_async(dispatch_get_main_queue(), ^{
               UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"The server is not responding \n please check your internet connection" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
               [alert show];
               alert=nil;
           });            
           NSLog(@"Nothing was downloaded.");
       }
       else if (error != nil){
  
           dispatch_async(dispatch_get_main_queue(), ^{
               UIAlertView *alert=[[UIAlertView alloc]initWithTitle:nil message:@"The server is not responding \n please check your internet connection" delegate:nil cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
               [alert show];
               alert=nil;
           });
           NSLog(@"Error happened = %@", error);
       }
   }];
  </code></pre>