(C) Download GMail Message Attachment by ID

Demonstrates how to download a GMail email attachment by the attachment ID.

For more information, see https://developers.google.com/gmail/api/v1/reference/users/messages/attachments/get

Chilkat C/C++ Library Downloads
MS Visual C/C++ Linux/CentOS C/C++ Alpine Linux C/C++ MAC OS X C/C++	armhf/aarch64 C/C++ C++ Builder iOS C/C++ Android C/C++	Solaris C/C++ MinGW C/C++

#include <C_CkHttp.h>
#include <C_CkStringBuilder.h>
#include <C_CkJsonObject.h>
#include <C_CkBinData.h>

void ChilkatSample(void)
    {
    HCkHttp http;
    BOOL success;
    const char *attachmentId;
    const char *messageId;
    const char *url;
    const char *outputFilePath;
    HCkStringBuilder sbJson;
    HCkJsonObject json;
    HCkBinData bd;

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

    http = CkHttp_Create();

    CkHttp_putAuthToken(http,"ACCESS_TOKEN");
    CkHttp_putAccept(http,"application/json");

    // See the following example:  Get GMail Message (format=full)
    // It shows how to download an email by message ID, and it shows how to parse the JSON
    // response which includes attachment names, ids, and other information.

    // This example will assume we already have the attachment id and filename.

    // This is the attachment ID for a file named "helloWorld.pdf".
    attachmentId = "ANGjdJ-oy3aCuZISJKLAhUdaEksCEklbAPyMaWzFgqOMGbPCRkgwgeu_Kttd99C17OBTHROkDZGekibTKWXGfscB5ww7fw4E65_V1dQ-jHhb2TD1Cdm58-BbNw2iDxzptco8iILPiSnLLfFn5Ps7nsRcxHaGTt3r0yqFKCuIYNnPK1vM04BXI_cfzo-HnI4I3tD6oHNHOGVQrL01MdShFQjPELPUjXM8z1qs7Kom-QyvV1iOldUN-66UuhynsmDX-CMM5TIdB-8KD_lmdhf-0DqG8JnCA20XpXyfqwS8XFkPA-t-QSjb7SdkHQFtQ4lz2PcBREFzZ2eI5j0l0Y_dQHRPYTeMwkVl1yl4MfFT4C4iso3VSF-eqaIjiFCbXKCFNyeEIW5WFsv189dhlSqU";

    messageId = "1712bc1dc22da2a2";

    CkHttp_SetUrlVar(http,"messageId",messageId);
    CkHttp_SetUrlVar(http,"attachmentId",attachmentId);

    url = "https://www.googleapis.com/gmail/v1/users/userId/messages/{$messageId}/attachments/{$attachmentId}";

    // When we download, the response is JSON that contains the attachment data base64url encoded, like this:
    // {
    //  "size": 934,
    //  "data": "JVBERi0xLjM ... CiUlRU9GCg=="
    // }

    outputFilePath = "qa_output/helloWorld.pdf";

    // Download into a StringBuilder.
    sbJson = CkStringBuilder_Create();
    success = CkHttp_DownloadSb(http,url,"utf-8",sbJson);
    if (success == FALSE) {
        printf("%s\n",CkHttp_lastErrorText(http));
        CkHttp_Dispose(http);
        CkStringBuilder_Dispose(sbJson);
        return;
    }

    if (CkHttp_getLastStatus(http) != 200) {
        // Something failed.
        // the JSON contains an error message.
        printf("%s\n",CkStringBuilder_getAsString(sbJson));
        CkHttp_Dispose(http);
        CkStringBuilder_Dispose(sbJson);
        return;
    }

    // Load into a Chilkat JSON object.
    json = CkJsonObject_Create();
    success = CkJsonObject_LoadSb(json,sbJson);

    // Extract the base64url data into a BinData.
    bd = CkBinData_Create();
    success = CkJsonObject_BytesOf(json,"data","base64url",bd);

    // Save the data to a file.
    success = CkBinData_WriteFile(bd,"qa_output/helloWorld.pdf");

    printf("Success.\n");


    CkHttp_Dispose(http);
    CkStringBuilder_Dispose(sbJson);
    CkJsonObject_Dispose(json);
    CkBinData_Dispose(bd);

    }