(C) Slack OAuth2

See more OAuth2 Examples

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

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#include <C_CkOAuth2.h>
#include <C_CkJsonObject.h>
#include <C_CkFileAccess.h>

void ChilkatSample(void)
    {
    HCkOAuth2 oauth2;
    const char *url;
    BOOL success;
    int numMsWaited;
    HCkJsonObject json;
    HCkFileAccess fac;

    // For more information about the OAuth2, see OAuth 2.0 Authorization Flow

    oauth2 = CkOAuth2_Create();

    // 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.
    CkOAuth2_putAppCallbackUrl(oauth2,"https://yourwebserver.com/oauth2_redirect");
    CkOAuth2_putListenPort(oauth2,3017);

    CkOAuth2_putAuthorizationEndpoint(oauth2,"https://slack.com/oauth/authorize");
    CkOAuth2_putTokenEndpoint(oauth2,"https://slack.com/api/oauth.access");

    // Replace these with actual values.
    CkOAuth2_putClientId(oauth2,"CLIENT_ID");
    CkOAuth2_putClientSecret(oauth2,"CLIENT_SECRET");

    CkOAuth2_putScope(oauth2,"team:read users:read");

    // Begin the OAuth2 Authorization code flow.  This returns a URL that should be loaded in a browser.
    url = CkOAuth2_startAuth(oauth2);
    if (CkOAuth2_getLastMethodSuccess(oauth2) != TRUE) {
        printf("%s\n",CkOAuth2_lastErrorText(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    printf("url = %s\n",url);

    // Launch the default browser on the system and navigate to the url.
    // The LaunchBrowser method was added in Chilkat v10.1.2.
    success = CkOAuth2_LaunchBrowser(oauth2,url);
    if (success == FALSE) {
        printf("%s\n",CkOAuth2_lastErrorText(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    // Wait for the user to approve or deny authorization in the browser.
    numMsWaited = 0;
    while ((numMsWaited < 90000) && (CkOAuth2_getAuthFlowState(oauth2) < 3)) {
        CkOAuth2_SleepMs(oauth2,100);
        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 (CkOAuth2_getAuthFlowState(oauth2) < 3) {
        CkOAuth2_Cancel(oauth2);
        printf("No response from the browser!\n");
        CkOAuth2_Dispose(oauth2);
        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 (CkOAuth2_getAuthFlowState(oauth2) == 5) {
        printf("OAuth2 failed to complete.\n");
        printf("%s\n",CkOAuth2_failureInfo(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    if (CkOAuth2_getAuthFlowState(oauth2) == 4) {
        printf("OAuth2 authorization was denied.\n");
        printf("%s\n",CkOAuth2_accessTokenResponse(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    if (CkOAuth2_getAuthFlowState(oauth2) != 3) {
        printf("Unexpected AuthFlowState:%d\n",CkOAuth2_getAuthFlowState(oauth2));
        CkOAuth2_Dispose(oauth2);
        return;
    }

    printf("OAuth2 authorization granted!\n");
    printf("Access Token = %s\n",CkOAuth2_accessToken(oauth2));

    // Get the full JSON response:
    json = CkJsonObject_Create();
    CkJsonObject_Load(json,CkOAuth2_accessTokenResponse(oauth2));
    CkJsonObject_putEmitCompact(json,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"
    // }

    printf("%s\n",CkJsonObject_emit(json));

    // Save the JSON to a file for future requests.
    fac = CkFileAccess_Create();
    CkFileAccess_WriteEntireTextFile(fac,"qa_data/tokens/slack.json",CkJsonObject_emit(json),"utf-8",FALSE);


    CkOAuth2_Dispose(oauth2);
    CkJsonObject_Dispose(json);
    CkFileAccess_Dispose(fac);

    }