(.NET Core C#) Yahoo Mail Refresh OAuth2 Access Token

See more Yahoo Mail Examples

Demonstrates how to refresh an OAuth2 Yahoo Mail access token.

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

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

// It is assumed we previously obtained an OAuth2 access token.
// This example loads the JSON access token file 
// saved by this example: Get Yahoo Mail OAuth2 Access Token

Chilkat.JsonObject jsonToken = new Chilkat.JsonObject();
bool success = jsonToken.LoadFile("qa_data/tokens/yahooMail.json");
if (success != true) {
    Debug.WriteLine("Failed to load googleSheets.json");
    return;
}

// The access token JSON looks like this:

// {
//   "access_token": "kCVQdnOdul...LHucA--",
//   "refresh_token": "AIenVWETSo0jklFBVkPS8vVm8E.Dj9ToRG.xDbDYmZ55WIs5t6CZhDkD",
//   "expires_in": 3600,
//   "token_type": "bearer",
//   "xoauth_yahoo_guid": "HGDQCVF6JB4YDOWHITPJFBHCWA"
// }

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

// See Step 5 at https://developer.yahoo.com/oauth2/guide/flows_authcode/
oauth2.TokenEndpoint = "https://api.login.yahoo.com/oauth2/get_token";

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

// Get the "refresh_token"
oauth2.RefreshToken = jsonToken.StringOf("refresh_token");

// Send the HTTP POST to refresh the access token..
success = oauth2.RefreshAccessToken();
if (success != true) {
    Debug.WriteLine(oauth2.LastErrorText);
    return;
}

// The response contains a new access token, but we must keep
// our existing refresh token for when we need to refresh again in the future.
jsonToken.UpdateString("access_token",oauth2.AccessToken);

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

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