Facebook Graph API not returning standard JSON - json

Question

I am working on an iOS app using the MonoTouch framework. I am using Visual Studio 2010 Professional SP1 with the Xamarin.iOS (v1.3.250) extension. I have been able to open a valid FacebookConnect.FBSession by using the FacebookConnect.FBLoginView with no issues but when I try to make a Graph API request using FacebookConnect.FBRequest I recieve a non-standard JSON style string. When I run following request through the Graph API Explorer:
me?fields=albums.fields(id,name,cover_photo)
I receive the following response:
{
"id": "111111111111111111",
"albums": {
"data": [
{
"id": "111111111111111111",
"name": "Some Album (#1)",
"cover_photo": "111111111111111111",
"created_time": "000-00-00T00:00:00+0000"
},
{
"id": "111111111111111111",
"name": "Some Album (#2)",
"cover_photo": "111111111111111111",
"created_time": "000-00-00T00:00:00+0000"
},
],
"paging": {
"cursors": {
"after": "xxxxxxxx=",
"before": "xxxxxxxx="
}
}
}
}
Now all of this is just fine and is what I expect to receive but when I make the same Graph API request from my app like this:
public static void GetPhotoAlbums(string _userID)
{
// _userID = "me"
mFBRequest = new FBRequest(FBSession.ActiveSession, _userID + "?fields=albums.fields(id,name,cover_photo)");
FBRequestConnection fbRequestConnection = new FBRequestConnection();
fbRequestConnection.AddRequest(mFBRequest, OnPhotoAlbumsReceived);
fbRequestConnection.Start();
}
static void OnPhotoAlbumsReceived(FBRequestConnection _connection, NSObject _result, NSError _error)
{
if (_error == null)
{
Console.WriteLine("FacebookManager.OnPhotoAlbumsReceived() - JSON: " + _result.Description);
object o = JsonConvert.DeserializeObject(_result.Description);
// ...
}
}
I receive this JSON 'like' response:
{
albums = {
data = (
{
"cover_photo" = 111111111111111111;
"created_time" = "000-00-00T00:00:00+0000";
id = 111111111111111111;
name = "Some Album (#1)";
},
{
"cover_photo" = 111111111111111111;
"created_time" = "000-00-00T00:00:00+0000";
id = 111111111111111111;
name = "Some Album (#2)";
},
);
paging = {
cursors = {
after = "xxxxxxxx=";
before = "xxxxxxxx=";
};
};
};
"id": "111111111111111111";
}
I'm not really sure how/why I'm getting a response formatted in a non-standard way but needless to say, I get Newtonsoft.Json.JsonReaderException when attempting to deserialize the data because it does not follow the standard formatting rules (ie, = instead of : to separate key/value pairs, ; instead of , to separate elements of a container, some keys having quotes while others do not, etc...)
I'm pretty new to Facebook and JSON stuff in general and am really at a loss for what is happening to the response string I receive. Any help, feedback, ideas are greatly appreciated. Thanks.

Answer 1

* Solution *
After a bunch of digging around it seems to be that the Graph API response is indeed JSON but it gets converted to an FBGraphObject which holds a NSMutableArray as it the data makes its way through the MonoTouch->.NET bindings so when I pulled _result.Description (equivalent to _result.ToString() it returned me the string representation of that object which happens to look a lot like JSON but is not. After finding all this out (and a lot of runtime experimentation), I was finally able to extract the data into a usable state by doing this:
static void OnPhotoAlbumsReceived(FBRequestConnection _connection, NSObject _result, NSError _error)
{
if (_error == null)
{
NSArray fieldData = (NSArray) _result.ValueForKeyPath(new NSString("albums.data.name"))
string[] names = NSArray.StringArrayFromHandle(fieldData.Handle);
// ...
}
}
Although this works for me, I have a feeling that there is a better or more robust way to get the data I requested, so if any developers out there can offer any additional tips for improving this solution, I would love to hear them.

Answer 2

As stated in Facebook SDK documentation Graph API:
When a request returns a non-JSON response (such as a "true" literal),
that response will be wrapped into a dictionary using this const as
the key. This only applies for very few Graph API prior to v2.1.
So you can check first if result is an NSDictionary, otherwise you can deserialize the JSON data as usual.
Below some obj-c code you can translate into C#/MonoTouch (I don't know the framework, I hope it is helpful).
NSDictionary *dict;
if ([graphResult isKindOfClass:[NSDictionary class]]) {
dict = (NSDictionary *)graphResult;
} else {
NSError *JSONError;
dict = [NSJSONSerialization JSONObjectWithData:graphResult options:NSJSONReadingAllowFragments error:&JSONError];
if (JSONError) {
NSLog(#"Facebook: JSON parse error: %#", JSONError);
// Handle error
}
}