sync Contacts between iPhone(also Android) and server

Question

I am in trouble and Need your help.

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1st Question:

My IOS app has to send/receive datas to/from a Web Server. The server defined using the TCP and the data format is TLV; I have never used TLV before, and have no idea how to solve this problem.

As for TCP, I decide to use cocoaAsyncSocket, it's simple to deal with TCP transports; But I send/receive datas all in the (NSData*) format, I don't know if the server can decode it correctly.

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2nd Question:

I am also trying to sync Contacts between local client and the server; the local client will be IOS app and Android app. Through I decide using vCard as the contacts' data format, but the vCard from iPhone contains some items(such as RelatedName) that not contained in Android; When I using vCard, there are some data lose, I can't solve this problem. Is there any good suggestion?

Somebody help me. Best regards.

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Finally, I decided to use cocoaAsyncScoket for transporting data and use SQLite for storing contacts's all data; And it seems avoiding data lose is not possible.

Answer 1

I completed it.

I used the GCDAsyncSocket lib to send & receive datas; As for TLV, just send the raw bytes in order under the custom defined rules will be fine.

The lib in github