(Unicode C) Square OAuth2 Access Token

Demonstrates how to get an access token for the Square API. This example is for desktop apps only (not web apps).

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#include <C_CkOAuth2W.h>
#include <C_CkStringBuilderW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkFileAccessW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkOAuth2W oauth2;
    const wchar_t *url;
    HCkStringBuilderW sbUrl;
    int numMsWaited;
    HCkJsonObjectW json;
    HCkFileAccessW fac;

    success = FALSE;

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

    oauth2 = CkOAuth2W_Create();

    // This should be the port in the localhost callback URL for your app.  
    // The callback URL would look like "http://localhost:3017/" if the port number is 3017.
    CkOAuth2W_putListenPort(oauth2,3017);

    // To use the production system, change the domains here to "connect.squareup.com"
    CkOAuth2W_putAuthorizationEndpoint(oauth2,L"https://connect.squareupsandbox.com/oauth2/authorize");
    CkOAuth2W_putTokenEndpoint(oauth2,L"https://connect.squareupsandbox.com/oauth2/token");

    // Replace these with actual values.
    CkOAuth2W_putClientId(oauth2,L"APPLICATION_ID");
    CkOAuth2W_putClientSecret(oauth2,L"APPLICATION_SECRET");

    // Make sure to include the scopes you'll need.
    CkOAuth2W_putScope(oauth2,L"ITEMS_WRITE ITEMS_READ");

    // Begin the OAuth2 three-legged flow.  This returns a URL that should be loaded in a browser.
    url = CkOAuth2W_startAuth(oauth2);
    if (CkOAuth2W_getLastMethodSuccess(oauth2) == FALSE) {
        wprintf(L"%s\n",CkOAuth2W_lastErrorText(oauth2));
        CkOAuth2W_Dispose(oauth2);
        return;
    }

    // Add the session=False query param to the URL.
    sbUrl = CkStringBuilderW_Create();
    CkStringBuilderW_Append(sbUrl,url);
    CkStringBuilderW_Append(sbUrl,L"&session=False");
    // Launch this URL in the browser.
    url = CkStringBuilderW_getAsString(sbUrl);

    // Launch the system's default browser navigated to the URL.
    success = CkOAuth2W_LaunchBrowser(oauth2,url);
    if (success == FALSE) {
        wprintf(L"%s\n",CkOAuth2W_lastErrorText(oauth2));
        CkOAuth2W_Dispose(oauth2);
        CkStringBuilderW_Dispose(sbUrl);
        return;
    }

    // Now wait for the authorization.
    // We'll wait for a max of 30 seconds.
    numMsWaited = 0;
    while ((numMsWaited < 30000) && (CkOAuth2W_getAuthFlowState(oauth2) < 3)) {
        CkOAuth2W_SleepMs(oauth2,100);
        numMsWaited = numMsWaited + 100;
    }

    // If there was no response from the browser within 30 seconds, then 
    // the AuthFlowState will be equal to 1 or 2.
    // 1: Waiting for Redirect. The OAuth2 background thread is waiting to receive the redirect HTTP request from the browser.
    // 2: Waiting for Final Response. The OAuth2 background thread is waiting for the final access token response.
    // In that case, cancel the background task started in the call to StartAuth.
    if (CkOAuth2W_getAuthFlowState(oauth2) < 3) {
        CkOAuth2W_Cancel(oauth2);
        wprintf(L"No response from the browser!\n");
        CkOAuth2W_Dispose(oauth2);
        CkStringBuilderW_Dispose(sbUrl);
        return;
    }

    // Check the AuthFlowState to see if authorization was granted, denied, or if some error occurred
    // The possible AuthFlowState values are:
    // 3: Completed with Success. The OAuth2 flow has completed, the background thread exited, and the successful JSON response is available in AccessTokenResponse property.
    // 4: Completed with Access Denied. The OAuth2 flow has completed, the background thread exited, and the error JSON is available in AccessTokenResponse property.
    // 5: Failed Prior to Completion. The OAuth2 flow failed to complete, the background thread exited, and the error information is available in the FailureInfo property.
    if (CkOAuth2W_getAuthFlowState(oauth2) == 5) {
        wprintf(L"OAuth2 failed to complete.\n");
        wprintf(L"%s\n",CkOAuth2W_failureInfo(oauth2));
        CkOAuth2W_Dispose(oauth2);
        CkStringBuilderW_Dispose(sbUrl);
        return;
    }

    if (CkOAuth2W_getAuthFlowState(oauth2) == 4) {
        wprintf(L"OAuth2 authorization was denied.\n");
        wprintf(L"%s\n",CkOAuth2W_accessTokenResponse(oauth2));
        CkOAuth2W_Dispose(oauth2);
        CkStringBuilderW_Dispose(sbUrl);
        return;
    }

    if (CkOAuth2W_getAuthFlowState(oauth2) != 3) {
        wprintf(L"Unexpected AuthFlowState:%d\n",CkOAuth2W_getAuthFlowState(oauth2));
        CkOAuth2W_Dispose(oauth2);
        CkStringBuilderW_Dispose(sbUrl);
        return;
    }

    wprintf(L"OAuth2 authorization granted!\n");
    wprintf(L"Access Token = %s\n",CkOAuth2W_accessToken(oauth2));

    // Get the full JSON response:
    json = CkJsonObjectW_Create();
    CkJsonObjectW_Load(json,CkOAuth2W_accessTokenResponse(oauth2));
    CkJsonObjectW_putEmitCompact(json,FALSE);

    // The JSON response looks like this:

    // {
    //   "access_token": "EAAAE...depV",
    //   "token_type": "bearer",
    //   "expires_at": "2020-09-04T23:30:18Z",
    //   "merchant_id": "MLQA83866KSR5",
    //   "refresh_token": "EQAAEE...jeVfD6MV"
    // }

    wprintf(L"%s\n",CkJsonObjectW_emit(json));

    // Save the JSON to a file for future requests.
    fac = CkFileAccessW_Create();
    CkFileAccessW_WriteEntireTextFile(fac,L"qa_data/tokens/square.json",CkJsonObjectW_emit(json),L"utf-8",FALSE);


    CkOAuth2W_Dispose(oauth2);
    CkStringBuilderW_Dispose(sbUrl);
    CkJsonObjectW_Dispose(json);
    CkFileAccessW_Dispose(fac);

    }