用php拉取Instagram信息 - 解码然后呢？

I'm pulling json from the Instagram API using a curl request. I want to cache this json to use from a mapping application (javascript).

Should I just pull straight from the API and cache the json, or is there some advantage to decoding it, doing something with the data, then re-encoding the json?

I was explaining this situation to a developer friend and he said something about decoding, cycling through the data, then re-encoding.

Other than changing the format of the data somehow -- which I thought of doing but decided to do client-side instead -- what's the advantage of doing it this way?

There is no right or wrong to what you ask. I'd say the following:

1. Cache the request: Caching the remote-request is most often useful, especially as you develop. You don't stress the remote server and you have responses nearly immediately at hand.
2. Caching the data-processing can make sense, too. Normally the actual data-processing does not take longer than the original request, but processing caching is known to be very useful as well for processing that take it's times.
3. Doing both - with different time-out configurations - is probably the high art of caching, but keep in mind that caching to work out best should be dead-simple. Processing caching can be normally neglected if you do already front-end caching, e.g. if you put your website behind a reverse-proxy (nginx, varnish).

There is no black or white, what's most important with caching: Do what works best for you.