/// <summary>
/// Gets the canvas login url
/// </summary>
/// <param name="returnUrlPath">
/// The return Url Path.
/// </param>
/// <param name="cancelUrlPath">
/// The cancel Url Path.
/// </param>
/// <param name="state">
/// The state.
/// </param>
/// <param name="loginParameters">
/// The parameters.
/// </param>
/// <returns>
/// Returns the login url.
/// </returns>
public Uri GetLoginUrl(string returnUrlPath, string cancelUrlPath, string state, IDictionary <string, object> loginParameters)
{
var oauth = new FacebookOAuthClient
{
AppId = _settings.AppId
};
var oauthJsonState = PrepareCanvasLoginUrlOAuthState(returnUrlPath, cancelUrlPath, state, loginParameters);
var oauthState = FacebookWebUtils.Base64UrlEncode(Encoding.UTF8.GetBytes(oauthJsonState.ToString()));
var mergedLoginParameters = FacebookUtils.Merge(loginParameters, null);
mergedLoginParameters["state"] = oauthState;
var appPath = _httpRequest.ApplicationPath;
if (appPath != "/")
{
appPath = string.Concat(appPath, "/");
}
string redirectRoot = RedirectPath;
var uriBuilder = new UriBuilder(CurrentCanvasUrl)
{
Path = string.Concat(appPath, redirectRoot),
Query = string.Empty
};
oauth.RedirectUri = uriBuilder.Uri;
var loginUrl = oauth.GetLoginUrl(mergedLoginParameters);
return(loginUrl);
}
/// <summary>
/// Builds a Facebook canvas return URL.
/// </summary>
/// <param name="pathAndQuery">The path and query.</param>
/// <returns>
/// The canvas url.
/// </returns>
public Uri BuildCanvasUrl(string pathAndQuery)
{
if (string.IsNullOrEmpty(pathAndQuery))
{
throw new ArgumentNullException("pathAndQuery");
}
pathAndQuery = FacebookWebUtils.RemoveStartingSlash(pathAndQuery);
var canvasUrl = IsSecureConnection ? SecureCanvasUrl : CanvasUrl;
if (canvasUrl.PathAndQuery != "/" && pathAndQuery.StartsWith(canvasUrl.PathAndQuery))
{
pathAndQuery = pathAndQuery.Substring(canvasUrl.PathAndQuery.Length);
}
var url = string.Concat(canvasUrl, pathAndQuery);
return(new Uri(FacebookWebUtils.RemoveTrailingSlash(url)));
}
protected Uri GetUrl(HttpContextBase context)
{
if (context == null)
{
throw new ArgumentNullException("context");
}
if (context.Request == null)
{
throw new Exception("context.Request is null");
}
// TODO: need unit tests for this method, might as well need to refactor this method.
UriBuilder redirectUriBuilder;
if (!context.Request.QueryString.AllKeys.Contains("state"))
{
// todo: better to redirect to the default canvas page.
return(new Uri("http://www.facebook.com"));
}
// if state is present.
var state = Encoding.UTF8.GetString(FacebookWebUtils.Base64UrlDecode(context.Request.QueryString["state"]));
var json = (IDictionary <string, object>)JsonSerializer.Current.DeserializeObject(state);
// make it one letter character so more info can fit in.
// r -> return_url_path (full uri)
// c -> cancel_url_path (full uri)
// s -> user_state
FacebookOAuthResult oauthResult;
if (!FacebookOAuthResult.TryParse(context.Request.Url, out oauthResult))
{
// todo: better to redirect to the default canvas page.
return(new Uri("http://www.facebook.com"));
}
if (oauthResult.IsSuccess)
{
var returnUrl = json["r"].ToString();
redirectUriBuilder = new UriBuilder(returnUrl);
if (returnUrl.Contains("?"))
{
// incase return url path contains querystrings.
var returnUrlParts = returnUrl.Split('?');
if (returnUrlParts.Length == 2 && !string.IsNullOrEmpty(returnUrlParts[1]))
{
var queryStrings = FacebookUtils.ParseUrlQueryString(returnUrlParts[1]);
if (queryStrings.ContainsKey("error_reason"))
{
// remove oauth stuffs.
if (queryStrings.ContainsKey("error_reason"))
{
queryStrings.Remove("error_reason");
}
if (queryStrings.ContainsKey("error"))
{
queryStrings.Remove("error");
}
if (queryStrings.ContainsKey("error_description"))
{
queryStrings.Remove("error_description");
}
redirectUriBuilder.Query = FacebookUtils.ToJsonQueryString(queryStrings);
}
}
}
}
else
{
if (!json.ContainsKey("c"))
{
// there is no cancel url path
redirectUriBuilder = new UriBuilder("http://facebook.com");
}
else
{
var cancelUrl = json["c"].ToString();
IDictionary <string, object> cancelUrlQueryStrings = new Dictionary <string, object>
{
{ "error_reason", context.Request.QueryString["error_reason"] },
{ "error", context.Request.QueryString["error"] },
{ "error_description", context.Request.QueryString["error_description"] }
};
if (cancelUrl.Contains("?"))
{
// incase cancel url path contains querystrings.
var cancelUrlParts = cancelUrl.Split('?');
if (cancelUrlParts.Length == 2 && !string.IsNullOrEmpty(cancelUrlParts[1]))
{
var queryStrings = FacebookUtils.ParseUrlQueryString(cancelUrlParts[1]);
cancelUrlQueryStrings = FacebookUtils.Merge(cancelUrlQueryStrings, queryStrings);
}
}
redirectUriBuilder = new UriBuilder(cancelUrl)
{
Query = FacebookUtils.ToJsonQueryString(cancelUrlQueryStrings)
};
}
}
return(redirectUriBuilder.Uri);
}
