I want to develop application same as UBER in which I need to show available taxis in the selected region and update as the taxis are hired, available, unavailable. Kind of auto refresh. Calling the web service in the background after regular time interval is not a good option. Can any one suggest me better and fast way to achieve this.
Thanks
You can use silent push notifications to update your map with updated taxi locations.
Push
Pull
Use a combination of approaches, since speed and robustness are mutually exclusive. Ultimately, your objective is to keep your local DB in sync with your server's DB, and fire internal messages as data changes. No small task, hence the Firebase answer.
The Most Simple way is to work with Firebase . Its No sql database and you will have instant update as you change anything .
This Video will guide you how speedy you can get update without any loop for refreshing data in application .
Ask me any help you need regarding Firebase .
I would suggest you take a look at CloudKit. There are several reasons.
Check out my detailed answer on SO for sharing the data between apps with CloudKit. Here is a link to some CloudKit videos that further describe how CloudKit works. Apple has lots of documentation and sample projects available. You can review the developer website for more info on CloudKit.
CloudKit Quick Start