Using Hashtable object as body/parameter for POST request (RestSharp in Xamarin Mono)

Question

I'm having issues making POST requests with RestSharp. My Hashtable object 'param' contains key-value pairs that must be posted to the server. I've tried several combinations and have gotten weird output on the server-side.

Example 1:

var client = new RestClient();
var request = new RestRequest(url, Method.POST);  
request.RequestFormat = DataFormat.Json;
request.AddBody (param);  

Output:

Parameters: {"_json"=>[{"Key"=>"customer_subject_id", "Value"=>"300"}, {"Key"=>"client_code", "Value"=>"337"}, {"Key"=>"reservation_id", "Value"=>"9798"}, {"Key"=>"guid", "Value"=>"ODUUME4qhLmAcBVGlT4mrGbaHcbuXZID"}, {"Key"=>"customer_client_subject_id", "Value"=>"300"}, {"Key"=>"exam_code", "Value"=>"300"}, {"Key"=>"signature", "Value"=>"6bcbffb0c8ddcd89f159cf5ddd485d1eed76d1694ba329db5431f883bac3e982"}, {"Key"=>"customer_id", "Value"=>"lol"}, {"Key"=>"session_duration", "Value"=>60}]}

Example 2:

var client = new RestClient();
var request = new RestRequest(url, Method.POST);  
foreach(DictionaryEntry entry in param){
 request.RequestFormat = DataFormat.Json;
 request.AddParameter ((entry.Key.ToString()), entry.Value);
}  

Output:

Parameters: {"customer_subject_id"=>"300", "client_code"=>"337", "reservation_id"=>"9798", "guid"=>"o9LJ5e9t52xxFhxhAoHzmYd7AiQ3nu36", "customer_client_subject_id"=>"300", "exam_code"=>"300", "signature"=>"297cd7e871df885393ebe44b262cb40b8c03e55ae1f0567ff708e9811b2aedf8", "customer_id"=>"lol", "session_duration"=>"60"}

The output for #2 seems correct, but I'm getting a 401 on the server-side. Weirdly, the GET output matches that of #2, but the request is made successfully. I think the problem may be that the request, in total, is posting 10 parameters yet it should be posting one JSON formatted string in the body. Typically, I would put a JSON formatted string in the body, but even when I use a standalone JSON serializer to obtain a JSON string of the Hashtable and put in AddBody, I get the following:

Example 3:

var client = new RestClient();
var request = new RestRequest(url, Method.POST);  
String paramJson = SimpleJson.SerializeObject (param);
request.RequestFormat = DataFormat.Json;
request.AddBody (paramJson);  

Output:

  Parameters: {"_json"=>"[{\"Key\":\"customer_subject_id\",\"Value\":\"300\"},{\"Key\":\"client_code\",\"Value\":\"337\"},{\"Key\":\"reservation_id\",\"Value\":\"9798\"},{\"Key\":\"guid\",\"Value\":\"56ZAsFtBx7jhDmdconWTb40qGirNagxK\"},{\"Key\":\"customer_client_subject_id\",\"Value\":\"300\"},{\"Key\":\"exam_code\",\"Value\":\"300\"},{\"Key\":\"signature\",\"Value\":\"57d7c878dec24da98815071d1dc3730873285b3ae65f9d98591da94266b8f7d7\"},{\"Key\":\"customer_id\",\"Value\":\"lol\"},{\"Key\":\"session_duration\",\"Value\":60}]"}

I'm mostly curious as to why the JSON string that RestSharp is creating contains "_json" at the beginning of it.

Thanks, John

Answer 1

Is your server running Rails? Maybe this is relevant https://groups.google.com/forum/#!topic/rubyonrails-core/ZYBI_XHYpak

If you have control of the server side, might be better to use AddParameter and pass a JSON string, which you can parse on the server side.