CODEWITHSUNDEEP
iosjsonafnetworking
David McGraw
David McGraw

Reputation: 5177

Using AFNetworking to process multiple JSON responses for a single request

I'm trying to find a way to open up a connection to a web service and have that service send down JSON objects on an as-needed basis.

Say I request 20 profiles from a service. Instead of waiting for the service to build all 20, the service would build the first profile and throw it back down to the client until all 20 are created.

I've been using AFNetworking and would like to continue using it. Eventually I'd like to contribute this component back to the community if it requires an addition.

Anyone have any ideas on tackling something like this? Right now I have a service pushing JSON every few seconds to test with.

Upvotes: 2

Views: 945

Answers (3)

mattt
mattt

Reputation: 19544

AFNetworking supports batching of requests with AFHTTPClient -enqueueBatchOfHTTPRequestOperations:progressBlock:completionBlock:.

You can use this method to return on each individual operation, as well as when all of the operations in the batch have finished.

Upvotes: 0

Rob
Rob

Reputation: 437592

A couple of thoughts:

  1. If you want to open a connection and respond to transmissions from the server, socket-based model seems to make sense. See Ray Wenderlich's How To Create A Socket Based iPhone App and Server for an example (the server-side stuff is likely to change based upon your server architecture, but it gives you an example). But AFNetworking is built on a NSURLConnection framework, not a socket framework, so if you wanted to integrate your socket classes into that framework, a non-inconsiderable amount of work would be involved.

  2. Another, iOS-specific model is to use Apple's push notification service (see the push-related sections of the Local and Push Notification Programming Guide).

  3. A third approach would be to stay with a pull mechanism, but if you're looking for a way to consume multiple feeds in a non-serial fashion would be to create multiple AFURLConnectionOperation (or the appropriate subclass) operations, and submit them concurrently (you may want to constraint maxConcurrentOperations on the queue to 4 or 5 as iOS can only have so many concurrent network operations). By issuing these concurrently, you mitigate many of the delays that result from network latencies. If you pursue this approach, some care might have to be taken for thread safety, but it's probably easier than the above two techniques.

Upvotes: 3

Adam Shiemke
Adam Shiemke

Reputation: 3742

This sounds like a job for a socket (or a web socket, whatever is easier).

I don't believe there is support for this in AF. This could be implemented in the NSURLConnection's didRecieveData method. This is triggered every time a piece of data is received, so you can do your parsing and messaging from that point. Unfortunately, I can't think of a very clean way to implement this.

Perhaps a better approach to this is to handle the appropriate rerequest via a pagination-style technique. You would request page 1 of profiles with 1/page, then request page 2, etc. You could then control the flow, i.e. if you want to request all in paralel or request one then the next sequentially. This would be less work to implement, and would (in my opinion) be cleaner and easier to maintain.

Upvotes: 1

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