Dropbox API and RestSharp for a C# developer

Update: The code in this post is out dated and the version of the API is no longer supported. To use the Dropbox API have a look at my open source projects DropNetRT or DropNet.

The Dropbox API has foiled my development of “Droppedboxx” for some time now. Mainly because the on site documentation is average for anyone not planning on developing for the iphone (dropbox, you used to be cool). Being a C# developer this was bad news for me but I decided to give it a go anyway and after a few weeks of failed attempts and a few emails to support about my issues I realised the API documentation on the dropbox website is slightly wrong.

So now that I have it working I thought i’d share this with my fellow .NET developers (and anyone else who will care to listen).

What you will need (What i used):

• RestSharp (What would i do without you…)
• Oauth Library for C# (this one seems the easiest to use with RestSharp)
• Access to the Dropbox API and an APIKey/Secret for your app

I guess I should start with the Setup of it, I started this as a Windows Mobile application but I switched to a .NET library so I could test it easier and also use RestSharp (might open source the library if I get around to it).

Login, this is possibly the easiest method if you have the right URL (the API documentation give you the wrong URL). We should be using “https://api.getdropbox.com/0/token” Code you say?

Update: Got some helpful advice about using the request.Resource property with parameters instead of a string.format.

public UserLogin Login(string email, string password)
{
    var restClient = new RestClient("https://api.getdropbox.com");
    var request = new RestRequest(Method.GET);
    request.Resource = "{version}/token";
    request.AddParameter("version", _version, ParameterType.UrlSegment);

    request.AddParameter("oauth_consumer_key", _apiKey);

    request.AddParameter("email", email);
    request.AddParameter("password", password);

    var response = restClient.Execute<UserLogin>(request);

    _userLogin = response.Data;

    return response.Data;
}

Seems pretty easy right? Most of thats RestSharp (with the JSONDeserializer), I then have the UserLogin class which is returned by this function.

public class UserLogin
{
    public string Token { get; set; }
    public string Secret { get; set; }
}

And now your user is logged in, you will then want to store the Users Token and Secret (storing UserLogin object would probably be better) as its used for the rest of the requests. I’ll just show you how to get the User Info as the other requests differ from the login (that is where we’ll need the Oauth stuff).

Account/Info, I’ll start with the Response classes this time…

public class AccountInfo
{
    public string Country { get; set; }
    public string Display_Name { get; set; }
    public QuotaInfo Quota_Info { get; set; }
    public string Uid { get; set; }
}

public class QuotaInfo
{
    public string Shared { get; set; }
    public string Quota { get; set; }
    public string Normal { get; set; }
}

These are the classes for RestSharp to Deserialize the JSON to. Pretty simple, this is straight off the API Documentation site. Now for the actual request…

public AccountInfo Account_Info()
{
    var restClient = new RestClient("http://api.dropbox.com");
    OAuthBase oAuth = new OAuthBase();
    string nonce = oAuth.GenerateNonce();
    string timeStamp = oAuth.GenerateTimeStamp();
    string normalizedUrl;
    string normalizedRequestParameters;
    string sig = oAuth.GenerateSignature(new Uri(string.Format("{0}/{1}/account/info", restClient.BaseUrl, _version)),
        _apiKey, _appsecret,
        _userLogin.Token, _userLogin.Secret,
        "GET", timeStamp, nonce, out normalizedUrl, out normalizedRequestParameters);
    sig = HttpUtility.UrlEncode(sig);

    var request = new RestRequest(Method.GET);
    request.Resource = string.Format("{0}/account/info", _version);
    request.AddParameter("oauth_consumer_key", _apiKey);
    request.AddParameter("oauth_token", _userLogin.Token);
    request.AddParameter("oauth_nonce", nonce);
    request.AddParameter("oauth_timestamp", timeStamp);
    request.AddParameter("oauth_signature_method", "HMAC-SHA1");
    request.AddParameter("oauth_version", "1.0");
    request.AddParameter("oauth_signature", sig);

    var response = restClient.Execute<AccountInfo>(request);

    return response.Data;
}

Now, this request has a different Base Url to the Login function and this uses OAuth. So firstly we create an instance of the RestSharp client and the OAutheBase classes. The OAuthBase class then handles all of the oauth parameters that we need to make the Request (nonce, timestamp, etc.). GenerateSignature is the main 1 that rolls up the request path and the tokens/secrets into a hash for extra security. As for the dropbox part of this, we dont need any extra parameters as we are just getting the logged in users Account Info. Then its just a matter of adding these parameters to the RestRequest object, notice the oauth_token is actually the UserLogin.Token that we got from our Login method?

Stay tuned for more, Tales of interest!

Update: I have added a Part 2 to this post.