/// <summary>
/// Sends an HTTP Request to the backend and parse the response (expected as a list of objects)
/// </summary>
/// <param name="action">action to query (e.g. "Snippets/Get")</param>
/// <param name="data">
/// if the request is a GET, the parameters to be put in the querystring (e.g. "snippetID=100"),
/// otherwise data to be put in the post (e.g. "content=...")
/// </param>
/// <param name="isPost">whether this request is a GET(false) or a POST(true)</param>
/// <param name="requiresLogin">false if this request calls a public web service</param>
/// <returns>null if any error occurred; the result of the invocation otherwise</returns>
protected S2CResListObj <string> SendReqListObj(string action, string data, bool isPost, bool requiresLogin = true)
{
string response = PrepareAndSendReq(action, data, isPost, requiresLogin);
if (string.IsNullOrEmpty(response))
{
ErrorCodes errCode = ErrorCodes.COMMUNICATION_ERROR;
if (WebConnector.Current.IsTimeout)
{
errCode = ErrorCodes.TIMEOUT;
}
SetLastError(log, errCode, S2CRes <string> .GetErrorMsg(errCode));
return(new S2CResListObj <string>(0.0, errCode, null, 0));
}
S2CResListObj <string> resp = S2CSerializer.DeserializeObjList(response, m_serialFormat);
if (!CheckResp <string>(resp))
{
PrintRespError <string>(resp);
//if the problem is related to user not logged in, reset login status and retry another time:
if (requiresLogin && (resp != null) && (resp.Status == ErrorCodes.NOT_LOGGED_IN))
{
WebConnector.Current.ResetLoginStatus(); //reset login status
//retry the WS call:
response = PrepareAndSendReq(action, data, isPost, requiresLogin);
resp = S2CSerializer.DeserializeObjList(response, m_serialFormat);
}
}
return(resp);
}
/// <summary>
/// Prints the info regarding the given erroneous response
/// </summary>
/// <param name="resp">response to print</param>
/// <returns></returns>
protected void PrintRespError <T>(S2CRes <T> resp)
{
if ((resp == null) || !(resp is S2CResObj <object>))
{
SetLastError(log, (resp == null ? ErrorCodes.FAIL : resp.Status), "Generic Error");
log.Warn("null response");
}
else
{
S2CResObj <T> errMessage = (S2CResObj <T>)resp;
SetLastError(log, resp.Status, errMessage.Data.PrintNull());
log.ErrorFormat("Error receiving the response: status={0}; messsage={1}", resp.Status, LastErrorMsg);
}
}
/// <summary>
/// Try to parse the given response that is expected to return a long result
/// </summary>
/// <returns></returns>
protected long ParseLongResponse <T>(S2CRes <T> resp)
{
if (!CheckResp <T>(resp))
{
PrintRespError <T>(resp);
return(-1);
}
long result = -1;
S2CResObj <T> value = (S2CResObj <T>)resp;
if (!long.TryParse(value.Data.ToString(), out result))
{
PrintRespError <T>(resp);
return(-1);
}
return(result);
}
/// <summary>
/// Try to parse the given response that is expected to return a boolean result
/// </summary>
/// <returns></returns>
protected bool ParseBoolResponse <T>(S2CRes <T> resp)
{
if (!CheckResp <T>(resp))
{
PrintRespError <T>(resp);
return(false);
}
bool result = false;
S2CResObj <T> value = (S2CResObj <T>)resp;
if (!bool.TryParse(value.Data.ToString(), out result))
{
PrintRespError <T>(resp);
return(false);
}
return(result);
}
/////////////////////////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// Checks that the given response is valid and can be safely parsed
/// </summary>
/// <param name="resp">response to validate</param>
/// <returns></returns>
protected bool CheckResp <T>(S2CRes <T> resp)
{
return((resp != null) && (resp.Status == ErrorCodes.OK)); // && (resp.Data != null));
}