(C++) Slack OAuth2

See more OAuth2 Examples

Note: This example requires Chilkat v10.1.2 or greater.

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#include <CkOAuth2.h>
#include <CkJsonObject.h>
#include <CkFileAccess.h>

void ChilkatSample(void)
    {
    // For more information about the OAuth2, see OAuth 2.0 Authorization Flow

    CkOAuth2 oauth2;

    // This example is for desktop applicatons (it is not for code that runs on a web server).

    // Your applicaton must use your own public web server as an intermediate
    // to receive and forward the redirect to localhost.
    // See Using Your Web Server as an Intermediary for OAuth2 Redirect to localhost

    // This is the Redirect URL defined for your Slack App in the Slack developer portal, and contains the above PHP.
    oauth2.put_AppCallbackUrl("https://yourwebserver.com/oauth2_redirect");
    oauth2.put_ListenPort(3017);

    oauth2.put_AuthorizationEndpoint("https://slack.com/oauth/authorize");
    oauth2.put_TokenEndpoint("https://slack.com/api/oauth.access");

    // Replace these with actual values.
    oauth2.put_ClientId("CLIENT_ID");
    oauth2.put_ClientSecret("CLIENT_SECRET");

    oauth2.put_Scope("team:read users:read");

    // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    const char *url = oauth2.startAuth();
    if (oauth2.get_LastMethodSuccess() != true) {
        std::cout << oauth2.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "url = " << url << "\r\n";

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    bool success = oauth2.LaunchBrowser(url);
    if (success == false) {
        std::cout << oauth2.lastErrorText() << "\r\n";
        return;
    }

    // Wait for the user to approve or deny authorization in the browser.
    int numMsWaited = 0;
    while ((numMsWaited < 90000) && (oauth2.get_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.get_AuthFlowState() < 3) {
        oauth2.Cancel();
        std::cout << "No response from the browser!" << "\r\n";
        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.get_AuthFlowState() == 5) {
        std::cout << "OAuth2 failed to complete." << "\r\n";
        std::cout << oauth2.failureInfo() << "\r\n";
        return;
    }

    if (oauth2.get_AuthFlowState() == 4) {
        std::cout << "OAuth2 authorization was denied." << "\r\n";
        std::cout << oauth2.accessTokenResponse() << "\r\n";
        return;
    }

    if (oauth2.get_AuthFlowState() != 3) {
        std::cout << "Unexpected AuthFlowState:" << oauth2.get_AuthFlowState() << "\r\n";
        return;
    }

    std::cout << "OAuth2 authorization granted!" << "\r\n";
    std::cout << "Access Token = " << oauth2.accessToken() << "\r\n";

    // Get the full JSON response:
    CkJsonObject json;
    json.Load(oauth2.accessTokenResponse());
    json.put_EmitCompact(false);

    // The JSON response looks like this:

    // {
    //   "ok": true,
    //   "access_token": "xoxp-348475395242-348621810805-4768936228341-9f512b295124e7c9846ce63cb1464c4d",
    //   "scope": "identify,team:read,users:read",
    //   "user_id": "UA8HZRUPP",
    //   "team_id": "TA3DZBN74",
    //   "enterprise_id": null,
    //   "team_name": "Chilkat Testing"
    // }

    std::cout << json.emit() << "\r\n";

    // Save the JSON to a file for future requests.
    CkFileAccess fac;
    fac.WriteEntireTextFile("qa_data/tokens/slack.json",json.emit(),"utf-8",false);
    }