问题
Is there a way to determine what kind of object is represented by the given ID https://graph.facebook.com/ID. When I'm requesting this in Graph API Explorer tool, in the response there is a field named type, that could contain user, page, album, photo and so on. But when I'm requesting the same from browser or via SDK, in response there is no such field, but everything else is the same. And I have to guess what kind of object I have relying on other fields: for example if there is a field gender that means that I have user object. I think this is a bug in FB Graph API. Is there any solution for this?
You can see the differences on the screenshots
回答1:
This is possible if you using something Facebook call "introspection" by adding metadata argument to your request:
GET http://graph.facebook.com/object_id?metadata=1
The result will contain type field
回答2:
You can add metadata=1 and response will have metadata: {type: ...} if you do request like that:
http://graph.facebook.com/object_id?metadata=1&fields=id,name,metadata{type}
Based on commend of Vinicius Tavares.
来源：https://stackoverflow.com/questions/8960911/determining-type-of-object-with-id-in-fb-graph-api