(Unicode C) PayPal Generate QR Code

Generates a QR code for an invoice, by ID.

The QR code is a PNG image in Base64-encoded format that corresponds to the invoice ID.

Note: A QR code can only be generated for an invoice that has been both created and sent.

See also Generate QR Code

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#include <C_CkJsonObjectW.h>
#include <C_CkStringBuilderW.h>
#include <C_CkRestW.h>
#include <C_CkBinDataW.h>

void ChilkatSample(void)
    {
    HCkJsonObjectW jsonToken;
    HCkStringBuilderW sbAuth;
    HCkRestW rest;
    BOOL bAutoReconnect;
    BOOL success;
    HCkStringBuilderW sbPath;
    int numReplacements;
    HCkStringBuilderW sbJsonResponse;
    HCkJsonObjectW json;
    HCkBinDataW pngData;

    // Note: Requires Chilkat v9.5.0.64 or greater.

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

    // Load our previously obtained access token. (see PayPal OAuth2 Access Token)
    jsonToken = CkJsonObjectW_Create();
    CkJsonObjectW_LoadFile(jsonToken,L"qa_data/tokens/paypal.json");

    // Build the Authorization request header field value.
    sbAuth = CkStringBuilderW_Create();
    // token_type should be "Bearer"
    CkStringBuilderW_Append(sbAuth,CkJsonObjectW_stringOf(jsonToken,L"token_type"));
    CkStringBuilderW_Append(sbAuth,L" ");
    CkStringBuilderW_Append(sbAuth,CkJsonObjectW_stringOf(jsonToken,L"access_token"));

    // Make the initial connection.
    // A single REST object, once connected, can be used for many PayPal REST API calls.
    // The auto-reconnect indicates that if the already-established HTTPS connection is closed,
    // then it will be automatically re-established as needed.
    rest = CkRestW_Create();
    bAutoReconnect = TRUE;
    success = CkRestW_Connect(rest,L"api.sandbox.paypal.com",443,TRUE,bAutoReconnect);
    if (success != TRUE) {
        wprintf(L"%s\n",CkRestW_lastErrorText(rest));
        CkJsonObjectW_Dispose(jsonToken);
        CkStringBuilderW_Dispose(sbAuth);
        CkRestW_Dispose(rest);
        return;
    }

    // ----------------------------------------------------------------------------------------------
    // The code above this comment could be placed inside a function/subroutine within the application
    // because the connection does not need to be made for every request.  Once the connection is made
    // the app may send many requests..
    // ----------------------------------------------------------------------------------------------

    // Build a path using an invoice ID.
    sbPath = CkStringBuilderW_Create();
    CkStringBuilderW_Append(sbPath,L"/v1/invoicing/invoices/invoice_id/qr-code");
    numReplacements = CkStringBuilderW_Replace(sbPath,L"invoice_id",L"INV2-ZG2H-HKAW-PMWU-N6ZR");

    CkRestW_AddHeader(rest,L"Authorization",CkStringBuilderW_getAsString(sbAuth));
    // A 500x500 image results in a PNG file of approx. 4K bytes in size.
    CkRestW_AddQueryParam(rest,L"width",L"500");
    CkRestW_AddQueryParam(rest,L"height",L"500");
    CkRestW_AddQueryParam(rest,L"action",L"pay");

    // Send the GET request and get the PNG image data as base64.
    // A successful JSON response looks like this:
    // {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
    sbJsonResponse = CkStringBuilderW_Create();
    success = CkRestW_FullRequestNoBodySb(rest,L"GET",CkStringBuilderW_getAsString(sbPath),sbJsonResponse);
    if (success != TRUE) {
        wprintf(L"%s\n",CkRestW_lastErrorText(rest));
        CkJsonObjectW_Dispose(jsonToken);
        CkStringBuilderW_Dispose(sbAuth);
        CkRestW_Dispose(rest);
        CkStringBuilderW_Dispose(sbPath);
        CkStringBuilderW_Dispose(sbJsonResponse);
        return;
    }

    json = CkJsonObjectW_Create();
    CkJsonObjectW_putEmitCompact(json,FALSE);
    CkJsonObjectW_LoadSb(json,sbJsonResponse);

    wprintf(L"Response Status Code = %d\n",CkRestW_getResponseStatusCode(rest));

    // Did we get a 200 success response?
    if (CkRestW_getResponseStatusCode(rest) != 200) {
        wprintf(L"%s\n",CkJsonObjectW_emit(json));
        wprintf(L"Failed.\n");
        CkJsonObjectW_Dispose(jsonToken);
        CkStringBuilderW_Dispose(sbAuth);
        CkRestW_Dispose(rest);
        CkStringBuilderW_Dispose(sbPath);
        CkStringBuilderW_Dispose(sbJsonResponse);
        CkJsonObjectW_Dispose(json);
        return;
    }

    // If the 200 response is received, the response body contains the PNG data.
    // Save the PNG to a file.
    pngData = CkBinDataW_Create();
    CkBinDataW_AppendEncoded(pngData,CkJsonObjectW_stringOf(json,L"image"),L"base64");
    success = CkBinDataW_WriteFile(pngData,L"qa_output/paypal_qr_code.png");
    if (success == FALSE) {
        wprintf(L"Failed to save PNG file.\n");
        CkJsonObjectW_Dispose(jsonToken);
        CkStringBuilderW_Dispose(sbAuth);
        CkRestW_Dispose(rest);
        CkStringBuilderW_Dispose(sbPath);
        CkStringBuilderW_Dispose(sbJsonResponse);
        CkJsonObjectW_Dispose(json);
        CkBinDataW_Dispose(pngData);
        return;
    }

    wprintf(L"Success.\n");


    CkJsonObjectW_Dispose(jsonToken);
    CkStringBuilderW_Dispose(sbAuth);
    CkRestW_Dispose(rest);
    CkStringBuilderW_Dispose(sbPath);
    CkStringBuilderW_Dispose(sbJsonResponse);
    CkJsonObjectW_Dispose(json);
    CkBinDataW_Dispose(pngData);

    }