Connecting to the Nike+ API with C#

A few months ago, I started writing some small personal apps which take information from the Nike+ service. Nike+ is the gadget I attach to my IPod and my running shoes which tracks details about my runs. It tracks things like distance, time, what I’m listening to, etc. When I sync the ipod, this information gets uploaded to the Nike+ website where I can see a couple of flash-heavy graphs of my running progress. Ideally, I would like to use this data myself–so I looked for an API.

I only found one example of an API referrence. This is a WordPress plugin written in PHP (http://www.ear-fung.us/apps/nikeplus/). There is very little documentation on the API out there. What I’ve been able to do involved a lot of trial and error to figure out how to get it working.

API Overview

Basically, the API (like most web-based APIs) includes a list of URLs which return an XML string. The first url will return an authentication cookie which all of the other urls use.

Here are the URLs:

Authenticating

The biggest problem I had when using these urls was how to deal with the cookie information. Since I wanted something that would sit outside the browser (like a sidebar gadget or a web component), I didn’t want to worry about only hosting one session at a time. So I captured the cookie information and fed it back to the server for each additional call.

        public  bool Authenticate()
        {

            //get the login URL (which I include app.config)
            string authURI = String.Format(ConfigurationSettings.AppSettings["CreateSession"].ToString()+"?login={0}&password={1}",
                    _userName, _passWord);

            //Make the call to initiate the connection
            WebRequest objRequest = System.Net.HttpWebRequest.Create(authURI);

            //Read the response
            WebResponse objResponse = objRequest.GetResponse();

            //a cookie will be returned for authentication-- catch it here
            _authenticationCookie = objResponse.Headers["SET-COOKIE"].ToString();

            StreamReader webResponse = new StreamReader(objResponse.GetResponseStream());

            XmlDocument dataDoc = new XmlDocument();
            dataDoc.LoadXml(webResponse.ReadToEnd());

            if (dataDoc.SelectSingleNode("//status").InnerText == "success")
            {
                return true;
            }
            else
            {
                return false;
            }

        }

The xml that’s returned is pretty simple, it returns a status node. The important thing it returns is the cookie.

I basically capture the cookie information in the “SET-COOKIE” information which gets passed in with the http header. I store this in a class variable so I can send it in with later calls.

Retrieving Data

Now that I’ve authenticated, all I need to do is pass the cookie details back to the api with each subsequent request.

        private XmlDocument getAdditionalDetails(string uri)
        {
            WebRequest objRequest = System.Net.HttpWebRequest.Create(uri);

            //return the authorization cookie
            objRequest.Headers.Add("Cookie", _authenticationCookie);

            WebResponse objResponse = objRequest.GetResponse();

            StreamReader webResponse = new StreamReader(objResponse.GetResponseStream());

            XmlDocument dataDoc = new XmlDocument();
            dataDoc.LoadXml(webResponse.ReadToEnd());

            return dataDoc;
        }

I do this by using the Headers.Add() function. I pass back the same information I retrieved on the initial request. I am no longer dependent on cookies at all. Now, I can read the xml in the application.

Reading the Data

The API does not have any published schemas. However, these are very easy to decipher once you read them. I’ve actually written an entire API wrapper which assigns these xml values to an object model. This is probably overkill, however. An example of the run list xml is below:

<?xml version="1.0" encoding="UTF-8"?>
<plusService>
  <status>success</status>
  <runList>
    <run id="888888">
      <startTime>2006-10-07T10:03:31+01:00</startTime>
      <distance>6.8276</distance>
      <duration>2035266</duration>
      <syncTime>2006-10-07T09:51:46+00:00</syncTime>
      <calories>631</calories>
      <name><![CDATA[]]></name>
      <description><![CDATA[]]></description>
    </run>
    <run id="99999999">
      <startTime>2006-10-10T08:26:10+01:00</startTime>
      <distance>4.51</distance>
      <duration>1331531</duration>
      <syncTime>2006-10-10T07:54:38+00:00</syncTime>
      <calories>417</calories>
      <name><![CDATA[]]></name>
      <description><![CDATA[]]></description>
    </run>
. . .