Add Decode functionality for paging results

[cbroglie]

No description provided.

[huandu]

@cbroglie You should not store original res in PagingResult. The res won't be changed by PageResult. So if a result navigates to next or previous page, res and the result are not the same.

Regarding to the function PagingResult#Decode, it may not be necessary and that useful from my point of view.

Here is a convenient way to decode struct from PagingResult using current api.

res := Result{
    "data": pagingResult.Data(),
}
var friends FacebookFriends
err := res.Decode(&friends)

As you can see, res in the sample is a waste. Personally I don't recommend to decode struct in this way. It's better to use []Result returned by PagingResult#Decode() and decode result one by one.

[cbroglie]

My original change was updating the result in navigate, so it did work. But I didn't realize Decode worked with a Result containing typed data, so your solution is simpler.

It's convenient to be able to decode the result into a single struct, instead of doing it each element at a time (that creates a lot of boiler plate code), so I would like to see PagingResult#Decode make it into the API.

[huandu]

OK. I found my assertion was wrong. You did update res in navigation properly.

Since there is no single-line-solution to decode from []Result right now, I agree that PagingResult#Decode can save some time in some case.

Last but not least, thanks for your contribution.

[cbroglie]

Thanks! I appreciate your work on this project, it's serving me well.