iPhone application architectures

Question

Hi, all!

Can you anyone point me to specific books or maybe give me a quick overview of how architectures of data-driven iPhone applications look like? For example, let's say you're implementing an application that searches online shopping sites and gives you recommendations..etc. Is it a common pattern to establish a hosted back-end of webservices which does all the database/shopping site API connections/webservices work and have the iPhone app consume services on this backend? or do you put everything in the iPhone application? Also, if you are establshing a web-services back-end, is it better to use REST/JSON vs REST/XML vs SOAP/XML...etc?

Thanks

Answer 1

To answer the first part of your question, I'd say that's up to you. If there's a lot of processing that needs doing between the web service and the iPhone, then maybe you should have your own backend server doing that processing before sending it to the iPhone. However, if you just need the data from the web service as-is on the iPhone, then just consume it directly.

As for the different formats, with the iPhone smaller is always better when it comes to network traffic. Stick with using REST for sure so you minimize data that needs to be transferred from the iPhone. As for JSON vs XML, obviously JSON is more lightweight which makes it a better candidate for the iPhone generally, but if your data requires a representation more complex than JSON can offer, then go with XML. Don't do SOAP if you can at all avoid it. It's just too heavyweight and will drain the iPhone's battery much more quickly with many requests.

If you are curious about the architecture and implementation details of a data-driven iPhone app, take a look at all of Apple's docs and tutorials about Core Data on the iPhone.