(C# UWP/WinRT) Yahoo Mail OAuth2 Access Token for Desktop App

See more Yahoo Mail Examples

Demonstrates how to get a Yahoo Email OAuth2 access token from a desktop application or script.

This example requires a browser window to be displayed to allow the Yahoo account owner to authorize the access. The code for displaying the web browser is omitted. Suggestions for a few programming languages are provided in code comments. You'll need to add the code to display a web browser and navigate to the URL returned by the call to oauth2.StartAuth.

For more information, see https://developer.yahoo.com/oauth2/guide/

Chilkat Universal Windows Platform (UWP) / WinRT Downloads Chilkat for the Universal Windows Platform (UWP)

// First, you must define your app in Yahoo Developer (https://developer.yahoo.com/apps/) like this:

// 

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

Chilkat.OAuth2 oauth2 = new Chilkat.OAuth2();
bool success;

// For a desktop app, you must provide a script on your web server to redirect to "http://localhost/<portNumber>"
// It can be written in C#, PHP, or whatever desired.  It must include the query string in the redirection.
// For example, in PHP your script would look like this:

// <?php
//   header( 'Location: http://localhost:3017?' . $_SERVER['QUERY_STRING'] );
// ?>

oauth2.AppCallbackUrl = "https://yourwebserver.com/OAuth2.php";
oauth2.ListenPort = 3017;

oauth2.AuthorizationEndpoint = "https://api.login.yahoo.com/oauth2/request_auth";
oauth2.TokenEndpoint = "https://api.login.yahoo.com/oauth2/get_token";

// Replace these with actual values.
oauth2.ClientId = "CLIENT_ID";
oauth2.ClientSecret = "CLIENT_SECRET";

// Do not send the "scope" query param for Yahoo OAuth2.
oauth2.UncommonOptions = "NO_OAUTH2_SCOPE";

// Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
string url = oauth2.StartAuth();
if (oauth2.LastMethodSuccess != true) {
    Debug.WriteLine(oauth2.LastErrorText);
    return;
}

Debug.WriteLine(url);

// At this point, your application should load the URL in a browser.
// For example, 
// in C#: System.Diagnostics.Process.Start(url);
// in Java: Desktop.getDesktop().browse(new URI(url));
// in VBScript: Set wsh=WScript.CreateObject("WScript.Shell")
//              wsh.Run url
// in Xojo: ShowURL(url)  (see http://docs.xojo.com/index.php/ShowURL)
// in Dataflex: Runprogram Background "c:\Program Files\Internet Explorer\iexplore.exe" sUrl        
// The Google account owner would interactively accept or deny the authorization request.

// Add the code to load the url in a web browser here...
// Add the code to load the url in a web browser here...
// Add the code to load the url in a web browser here...
// System.Diagnostics.Process.Start(url);

// Now wait for the authorization.
// We'll wait for a max of 30 seconds.
int numMsWaited = 0;
while ((numMsWaited < 30000) && (oauth2.AuthFlowState < 3)) {
    oauth2.SleepMs(100);
    numMsWaited = numMsWaited + 100;
}

// If there was no response from the browser within 30 seconds, then 
// the AuthFlowState will be equal to 1 or 2.
// 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
// 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
// In that case, cancel the background task started in the call to StartAuth.
if (oauth2.AuthFlowState < 3) {
    oauth2.Cancel();
    Debug.WriteLine("No response from the browser!");
    return;
}

// Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
// The possible AuthFlowState values are:
// 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
// 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
// 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
if (oauth2.AuthFlowState == 5) {
    Debug.WriteLine("OAuth2 failed to complete.");
    Debug.WriteLine(oauth2.FailureInfo);
    return;
}

if (oauth2.AuthFlowState == 4) {
    Debug.WriteLine("OAuth2 authorization was denied.");
    Debug.WriteLine(oauth2.AccessTokenResponse);
    return;
}

if (oauth2.AuthFlowState != 3) {
    Debug.WriteLine("Unexpected AuthFlowState:" + Convert.ToString(oauth2.AuthFlowState));
    return;
}

// Save the full JSON access token response to a file.
Chilkat.StringBuilder sbJson = new Chilkat.StringBuilder();
sbJson.Append(oauth2.AccessTokenResponse);
sbJson.WriteFile("qa_data/tokens/yahooMail.json","utf-8",false);

// The saved JSON response looks like this:

// {
//   "access_token": "kCVQdnOdul...LHucA--",
//   "refresh_token": "AIenVXETSo0jklFBVkPS8vVm8E.Ej9ToRG.xDbDYmZ65WIs5t6CZhDrD",
//   "expires_in": 3600,
//   "token_type": "bearer",
//   "xoauth_yahoo_guid": "HGDQCVF5JB4YDOWHITQJFBHCWA"
// }

Debug.WriteLine("OAuth2 authorization granted!");
Debug.WriteLine("Access Token: " + oauth2.AccessToken);