CODEWITHSUNDEEP
iphoneioshttpclient-server
dscTobi
dscTobi

Reputation: 157

iOS. Best way to pull data from a server (dynamic intervals) for HTTP chat client?

I am working on a chat client. To get new messages (or post new one) I have to perform GET (or POST) request. All new messages are stored via core data. At the moment I don't know how to implement it in most optimal way.

My thoughts:

  1. On view controller init stage create background thread which will periodically checks for new messages (if conversation is active - with short period, if not - with period about 60 secs). If there are new messages, we store them in DB and signal delegate that there are new messages to display.
  2. Friend suggested to use performSelector afterDelay, but I don't understand how to use it in my app.
  3. Something else?

Thanks in advance.

Upvotes: 0

Views: 166

Answers (1)

Wain
Wain

Reputation: 119031

Don't use performSelector afterDelay. Using NSTimer is much better (as the trigger for starting the next download). Also, use NSOperationQueue to manage your background tasks. Create yourself a custom NSOperation that you can instantiate and it will complete your request process. When you create a new operation to check for new messages, check if one is already in progress (there is no point having multiple requests in progress at the same time).

Other notes:

  1. Make sure you consider the threading with regards to the Core Data store (having the operation call back to the main thread with the results will probably be easiest as the result data will always be relatively small).
  2. If you have lots of messages being sent and you want to show constant status (like Skype does, showing you when someone is typing) you would need to use sockets to keep the connection alive the whole time (the cost of new connections each time would be prohibitive).

Upvotes: 1

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