How does express accept data from angular using $http.post

  node.js, question

I used angular post to send an object to the node server similar to:

var obj = {};
 obj.title = "title";
 obj.data = {expire:new Date(), detail:{data:[1,2,3]}}
 $http.post('host', {obj:obj})
 .success(function(suc){
 //success callback
 })

The data of express3.x, req.body used by node seems to have been passed by toString (). Nested objects are parsed into empty strings. I don’t know what to do.

Use browser console
For example, the chrome console looks at what data was sent in the past.
Is it correctly converted to JSON-formatted string