Node.js

Facebook OAuth2 Access Token

See more Facebook Examples

Demonstrates how to get a Facebook OAuth2 access token from a desktop application or script. Node.js

NODEJS_PRELUDE

function chilkatExample() {

    var success = false;

    // To further clarify, see OAuth 2.0 Authorization Flow

    var oauth2 = new chilkat.OAuth2();

    // This should match the Site URL configured for your Facebook APP, such as "http://localhost:3017/"
    oauth2.ListenPort = 3017;

    oauth2.AuthorizationEndpoint = "https://www.facebook.com/dialog/oauth";
    oauth2.TokenEndpoint = "https://graph.facebook.com/oauth/access_token";

    // Replace this with your actual App ID
    oauth2.ClientId = "APP_ID";

    // Set the Scope to a comma-separated list of permissions the app wishes to request.
    // See https://developers.facebook.com/docs/facebook-login/permissions/ for a full list of permissions.
    oauth2.Scope = "public_profile,user_friends,email,user_posts,user_likes,user_photos";

    // This is for Require Proof Key for Code Exchange (PKCE)
    // See OAuth2 PKCE Explained
    oauth2.CodeChallenge = true;
    oauth2.CodeChallengeMethod = "S256";

    // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    var url = oauth2.StartAuth();
    if (oauth2.LastMethodSuccess !== true) {
        console.log(oauth2.LastErrorText);
        return;
    }

    console.log("url = " + url);

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    success = oauth2.LaunchBrowser(url);
    if (success == false) {
        console.log(oauth2.LastErrorText);
        return;
    }

    // Wait for the user to approve or deny authorization in the browser.
    var numMsWaited = 0;
    while ((numMsWaited < 90000) && (oauth2.AuthFlowState < 3)) {
        oauth2.SleepMs(100);
        numMsWaited = numMsWaited+100;
    }

    // If the browser does not respond within the specified time, AuthFlowState will be:
    // 
    // 1: Waiting for Redirect – The OAuth2 background thread is waiting for the browser's redirect request.
    // 2: Waiting for Final Response – The thread is awaiting the final access token response.
    // In either case, cancel the background task initiated by StartAuth.

    if (oauth2.AuthFlowState < 3) {
        oauth2.Cancel();
        console.log("No response from the browser!");
        return;
    }

    // Check AuthFlowState to determine if authorization was granted, denied, or failed:
    // 
    // 3: Success – OAuth2 flow completed, the background thread exited, and the successful response is in AccessTokenResponse.
    // 4: Access Denied – OAuth2 flow completed, the background thread exited, and the error response is in AccessTokenResponse.
    // 5: Failure – OAuth2 flow failed before completion, the background thread exited, and error details are in FailureInfo.

    if (oauth2.AuthFlowState == 5) {
        console.log("OAuth2 failed to complete.");
        console.log(oauth2.FailureInfo);
        return;
    }

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

    if (oauth2.AuthFlowState !== 3) {
        console.log("Unexpected AuthFlowState:" + oauth2.AuthFlowState);
        return;
    }

    console.log("OAuth2 authorization granted!");
    console.log("Access Token = " + oauth2.AccessToken);

}

chilkatExample();