(C# UWP/WinRT) MercadoLibre Refresh OAuth2 Access Token

Demonstrates how to refresh a MercadoLibre OAuth2 access token. The refresh does not require user interaction via a web browser. If an access token expires (typically with a 401 response code), a new access token can be automatically obtained by using the code in this example.

For more information, see https://developers.mercadolibre.com.ar/es_ar/autenticacion-y-autorizacion#Refresh-token

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

// 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 MercadoLibre OAuth2 Access Token

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

// The access token JSON looks like this:

// {
//   "access_token": "APP_USR-8133606632685744-060115-93e1fd8b5e767c51c238df347bd0b288-577628017",
//   "token_type": "bearer",
//   "expires_in": 21600,
//   "scope": "offline_access read write",
//   "user_id": 577625107,
//   "refresh_token": "TG-5ad522a286f1200006ac4ed1-577625007"
// }

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

oauth2.TokenEndpoint = "https://api.mercadolibre.com/oauth/token";

// Replace these with actual values.
oauth2.ClientId = "MY_MERCADOLIBRE_APP_ID";
oauth2.ClientSecret = "MY_MERCADOLIBRE_APP_SECRET";

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

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

Debug.WriteLine("New access token: " + oauth2.AccessToken);
Debug.WriteLine("New refresh token: " + oauth2.RefreshToken);

// Update the JSON with the new tokens.
jsonToken.UpdateString("access_token",oauth2.AccessToken);
jsonToken.UpdateString("refresh_token",oauth2.RefreshToken);

// 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/mercadolibre.json","utf-8",false);

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