HttpHelper

This project has been renamed and was formerly called FluentHttp.Core.

Overview

HttpHelper is a light weight library aimed to ease the development for your rest client with consistent api throughout different frameworks whether you are using .net 2.0+ or silverlight or window phone. (It is not aimed to be used directly by the developers, but rather for creating a http client wrapper, such as for Facebook, Github, Twitter, Google etc.)

Supported Frameworks

• .NET 4.5
• .NET 4.0 (client profile supported)
• .NET 3.5 (client profile supported)
• .NET 3.0
• .NET 2.0
• Windows 8 Metro Style Applications - WinRT
• Silverlight 4.0+
• Windows Phone 7+
• Portable Library - #define HTTPHELPER_PORTABLE_LIBRARY
• Mono

NuGet

Install-Package HttpHelper

Samples

Note:

• Developer is reponsible for manually disposing request (write) and response (read) streams.
• Always create new instance of HttpHelper for each new requests.

HTTP GET

Synchronous Sample

Synchronous methods are not supported in Silverlight/Windows Phone/WinRT (Windows Metro Apps)

Make a GET request to https://graph.facebook.com/4 and return the response as string.

public static string GetSyncSample()
{
    var httpHelper = new HttpHelper("https://graph.facebook.com/4");

    using (var stream = httpHelper.OpenRead())
    {
        using (var reader = new StreamReader(stream))
        {
            return reader.ReadToEnd();
        }
    }
}

Asynchronous Sample with Async/Await

Available only in .NET 4.5+, and WinRT (Windows Metro Apps)

Make an asynchrounous GET request to https://graph.facebook.com/4 and return the response as task of string.

HTTPHELPER_TPL conditional compilation symbol must be defined in order to use XTaskAsync methods.

public static async Task<string> GetAsyncAwaitSample(CancellationToken cancellationToken = default(CancellationToken))
{
    var httpHelper = new HttpHelper("https://graph.facebook.com/4");

    using (var stream = await httpHelper.OpenReadTaskAsync(cancellationToken))
    {
        using (var reader = new StreamReader(stream))
        {
            return reader.ReadToEnd();
        }
    }
}

Asynchronous Sample with Task Parallel Library (TPL)

Available only in .NET 4.0+, SL5 and WinRT (Windows Metro Apps)

Make an asynchrounous GET request to https://graph.facebook.com/4 and return the response as task of string.

HTTPHELPER_TPL conditional compilation symbol must be defined in order to use XTaskAsync methods.

public static Task<string> GetAsyncTaskSample(CancellationToken cancellationToken = default(CancellationToken))
{
    var httpHelper = new HttpHelper("https://graph.facebook.com/4");

    return httpHelper
        .OpenReadTaskAsync(cancellationToken)
        .ContinueWith(t =>
                          {
                              // propagate previous task exceptions correctly.
                              if (t.IsFaulted || t.IsCanceled) t.Wait();

                              using (var stream = t.Result)
                              {
                                  using (var reader = new StreamReader(stream))
                                  {
                                      return reader.ReadToEnd();
                                  }
                              }
                          });
}

Asynchronous Sample with Event Programming Model (EPM)

Available in all .NET plaforms.

Make an asynchrounous GET request to https://graph.facebook.com/4 and call the callback on completion. Action<string, object, bool, Exception> is mapped to response string, userState, isCancelled and Exception.

public static void GetAsyncSample(Action<string, object, bool, Exception> callback = null, object userState = null)
{
    var httpHelper = new HttpHelper("https://graph.facebook.com/4");

    httpHelper.OpenReadCompleted +=
        (o, e) =>
        {
            if (callback == null)
            {
                // make sure to dispose the response stream
                if(!e.Cancelled && e.Error != null)
                    using (var stream = e.Result) { }
                return;
            }

            if (e.Cancelled)
                callback(null, e.UserState, true, null);
            else if (e.Error != null)
                callback(null, e.UserState, false, e.Error);
            else
            {
                try
                {
                    using (var stream = e.Result)
                    {
                        using (var reader = new StreamReader(stream))
                        {
                            callback(reader.ReadToEnd(), e.UserState, false, null);
                        }
                    }
                }
                catch (Exception ex)
                {
                    callback(null, e.UserState, false, ex);
                }
            }
        };

    httpHelper.OpenReadAsync(userState);
}

You can cancel the asynchronous requests for EPM using httpHelper.CancelAsync() method.

HTTP POST

Synchronous Sample

Synchronous methods are not supported in Silverlight/Windows Phone/WinRT (Windows Metro Apps)

Make a POST request to https://graph.facebook.com/me/feed and return the response as string. For the below sample you can get the access_token from http://developers.facebook.com/tools/explorer/ Make sure you have publish_stream extended permission which is required to post to your facebook wall.

HTTPHELPER_URLENCODING conditional compilation symbol must be defined in order to use HttpHelper.UrlEncode or HttpHelper.UrlDecode methods.

Windows Phone and WinRT (Windows Metro Apps) do not have the property ContentLength for HttpWebRequest. In order to reduce the #if (WINDOWS_PHONE || NETFX_CORE) you can use the TrySetContentLength method.

public static string PostSyncSample(IEnumerable<KeyValuePair<string, string>> parameters)
{
    var httpHelper = new HttpHelper("https://graph.facebook.com/me/feed");
    var request = httpHelper.HttpWebRequest;
    request.Method = "POST";
    request.ContentType = "application/form-url-encoded";

    var bodyString = new StringBuilder();
    foreach (var kvp in parameters)
        bodyString.AppendFormat("{0}={1}&", HttpHelper.UrlEncode(kvp.Key), HttpHelper.UrlEncode(kvp.Value));
    if (bodyString.Length > 0)
        bodyString.Length -= 1;

    var bodyByteArray = Encoding.UTF8.GetBytes(bodyString.ToString());
    request.TrySetContentLength(bodyByteArray.Length);

    // write to request body only if we have data, otherwise directly open the read stream
    if (bodyByteArray.Length > 0)
    {
        using (var stream = httpHelper.OpenWrite())
        {
            stream.Write(bodyByteArray, 0, bodyByteArray.Length);
        }
    }

    using (var stream = httpHelper.OpenRead())
    {
        using (var reader = new StreamReader(stream))
        {
            return reader.ReadToEnd();
        }
    }
}

var parameters = new Dictionary<string, string>();
parameters["message"] = "Hi from HttpHelper";
parameters["access_token"] = "";
var result = PostSyncSample(parameters);
Console.WriteLine(result);

Twitter OAuth Sample

HttpHelper includes some basic helper methods for oauth 1.0.

Here is a sample on getting the request token from twitter.

Note: GenerateOAuthAuthenticationHeader will auto generate timestamps/oauth nonce values if you pass it as null. You can either manually pass your own value or use the helper methods such as HttpHelper.GenerateOAuthNonce(), HttpHelper.GenerateOAuthTimestamp. Since HMAC-SHA1 is not avaialble in the portable library, you will need to add reference to Portable Library Contrib project and pass the appropriate HmacSha1Delegate.

Make sure add #define HTTPHELPER_TPL if you want to use OpenReadTaskAsync method.

public static async Task<IDictionary<string, string>> GetRequestToken(string consumerKey, string consumerSecret, CancellationToken cancellationToken = default (CancellationToken))
{
    var requestTokenUri = new Uri("https://api.twitter.com/oauth/request_token");

    var httHelper = new HttpHelper(requestTokenUri);
    var request = httHelper.HttpWebRequest;
    request.Method = "POST";
    request.ContentType = "application/json";

    request.Headers["Authorization"] = HttpHelper.GenerateOAuthAuthenticationHeader(
        "POST", requestTokenUri, null,
        consumerKey, consumerSecret,
        null, null,
        "HMAC-SHA1", null, null, null, null);

    using (var stream = await httHelper.OpenReadTaskAsync(cancellationToken))
    {
        using (var reader = new StreamReader(stream))
        {
            var response = await reader.ReadToEndAsync();

            var kvp = response.Split('&');
            var dict = new Dictionary<string, string>();
            foreach (var s in kvp)
            {
                var pair = s.Split('=');
                if (pair.Length == 2)
                    dict[pair[0]] = pair[1];
            }

            return dict;
        }
    }
}

Then generate the login url and open it in the browser.

var requestTokenResult = await GetRequestToken("consumerKey", "consumerSecret");

string token = requestTokenResult["oauth_token"];
string tokenSecret = requestTokenResult["oauth_token_secret"];

Process.Start("https://api.twitter.com/oauth/authorize?oauth_token=" + token);

Once you have granted access you will get some random pin number. Then get the access token use the pin.

public static async Task<IDictionary<string, string>> GetAccessToken(string consumerKey, string consumerSecret, string token, string tokenSecret, string oauthVerifierPin, CancellationToken cancellationToken = default (CancellationToken))
{
    var requestTokenUri = new Uri("https://api.twitter.com/oauth/access_token");

    var httHelper = new HttpHelper(requestTokenUri);
    var request = httHelper.HttpWebRequest;
    request.Method = "POST";
    request.ContentType = HttpHelper.ApplicationXWWWFormUrlEncodedContentType;
    var data = Encoding.UTF8.GetBytes(string.Concat("oauth_verifier=", oauthVerifierPin));
    request.TrySetContentLength(data.Length);

    var parameters = new Dictionary<string, string>();
    parameters["oauth_verifier"] = oauthVerifierPin;

    request.Headers["Authorization"] = HttpHelper.GenerateOAuthAuthenticationHeader(
        "POST", requestTokenUri, parameters,
        consumerKey, consumerSecret,
        token, tokenSecret,
        "HMAC-SHA1", null, null, null, null);

    using (var stream = await httHelper.OpenWriteTaskAsync(cancellationToken))
    {
        await stream.WriteAsync(data, 0, data.Length, cancellationToken);
    }

    using (var stream = await httHelper.OpenReadTaskAsync(cancellationToken))
    {
        using (var reader = new StreamReader(stream))
        {
            var response = await reader.ReadToEndAsync();

            var kvp = response.Split('&');
            var dict = new Dictionary<string, string>();
            foreach (var s in kvp)
            {
                var pair = s.Split('=');
                if (pair.Length == 2)
                    dict[pair[0]] = pair[1];
            }

            return dict;
        }
    }
}

string pin = "...";

var accessTokenResult = await GetAccessToken(consumerKey, consumerSecret, token, tokenSecret, pin);
var oauthToken = accessTokenResult["oauth_token"];
var oauthTokenSecret = accessTokenResult["oauth_token_secret"];
var userId = accessTokenResult["user_id"];
var screenName = accessTokenResult["screen_name"];