Xamarin.Forms.OAuth

Usage

To use this library, only three steps are needed:

0. Register your app with the provider(s)

The link to each provider's registration page is available in the wiki.

1. Add NuGet Package

Use Package Manager Console to install the library in your Xamrain.Forms (Portable) project.

PM> Install-Package Xamarin.Forms.OAuth 

NuGet Link

2. Add your provider(s)

For instance, in your App.cs file, add your providers:

public App()
{
  OAuthAuthenticator.AddPRovider(OAuthProviders.Facebook("FacebookAppId"));
  OAuthAuthenticator.AddPRovider(OAuthProviders.Google("GoogleClientId", "RedirectUrlConfiguredInGoogleAppConsole"));
  OAuthAuthenticator.AddPRovider(OAuthProviders.Microsoft("MicrosoftClientId", "RedirectUrlConfiguredInMicrosoftDeveloperApp"));
  
  OAuthAuthenticator.AddPRovider(OAuthProviders.Custom(
    "Name", 
    "https://authorizeUlr", 
    "http://redirectUrl", 
    "http://accountUrl", 
    "ClientId", 
    logo: ImageSource.FromUri("http://logUrl.png"));
  
  // The root page of your application
  // ...
}

3. Call for authentication when you need it:

var authenticationResult = await OAuthAuthenticator.Authenticate();

if (authenticationResult)
{
  var providerName  = authenticationResult.Account.Provider;
  var accountId = authenticationResult.Account.Id;
  var accountDisplayName = authenticationResult.Account.DisplayName;
  var accessToken = authenticationResult.Account.AccessToken;
  // ...
}
else
{
  var errorDescription = authenticationResult.ErrorDescription;
  // ...
}

3a. Inject provider manually

If only one provider is used or if a custom provider selection outside this library is used, authentication can be invoked with the intended provider:

var authenticationResult = await OAuthAuthenticator.Authenticate(OAuthProvider.Facebook("FacebookAppId"));

if (authenticationResult)
{
  // ...
}
else
{
  var errorMessage = authenticationResult.ErrorMessage;
  // ...
}

4. Resource Access

The account in the result can be used to access the provider's result taking care of all the OAuth parameters injection (Post is also available):

// GET
var authenticationResult = await OAuthAuthenticator.Authenticate(OAuthProvider.Facebook("FacebookAppId"));
var resourceString = await authenticationResult.Account.GetResource<string>("https://graph.facebook.com/v2.5/me");
// or
var resourceJObject = await authenticationResult.Account.GetResource<JObject>("https://graph.facebook.com/v2.5/me");
// or
var resourceType =  = await authenticationResult.Account.GetResource<ResourceType>("https://graph.facebook.com/v2.5/me");

// or POST
var httpContent = new StringContent("to send to API"); // can be any type deriving from System.Net.Http.HttpContent
var resource = await authenticationResult.Account.PostToreResource<string>("resourceUrl", httpContent);
// same deserialization of response can be handle as above

5. Refresh Token

If the provider supports it and a refresh token was provided, theh access token can be refreshed:

var authenticationResult = await OAuthAuthenticator.Authenticate(OAuthProvider.Facebook("FacebookAppId"));
if (authenticationResult.Account.RefreshesToken 
    && authenticationResult.Account.AccessToken.Expires.HasValue 
    && authenticationResult.Account.AccessToken.Expires.Value - DateTime.Now < TimeSpan.FromMinutes(5))
  {
    var response = await result.Account.RefreshToken();
    if (response)
    {
      // if this is reached, result.Account.AccessToken will be updated with new token and expiration DateTime
    }
    else
    {
      //Handle error using response.Error and response.ErrorDescription
    }
  }
  // 

Customization

A set of customizations are provided. Here is their usage.

Select Provider Text

OAuthAuthenticator.SetProviderSelectText("Pick one:"));

Back Button Text

OAuthAuthenticator.SetBackButtonText("Go Back!"));

Provider's Button Styling

OAuthAuthenticator.SetProviderButtonBackground(Color.Red));
OAuthAuthenticator.SetProviderButtonTextColor(Color.FromHex("FFFF00")));
OAuthAuthenticator.SetProviderButtonFontSize(38));

Screenshots

Supported Providers

Here is the list of the OAuth providers suported out-of-the-box (20):

• Amazon
• Box
• Dropbox
• Facebook
• Foursquare
• GitHub
• Gitter
• Google
• Instagram
• LinkedIn
• Microsoft
• PayPal
• ReddIt
• Salesforce
• Slack
• SoundCloud
• StackExchange
• Visual Studio Online
• Meetup
• Trello

Future Features

These are the features that will be impleneted next:

• Implement more providers (feel free to suggest):
  • Atlassian products (JIRA, Bamboo, Bitbucket)
  • Skype for Business
  • Microsft Graph
• Feel free to point buts or any feature or provider you would like implemented on