(Unicode C) Get GMail Message Metadata

Demonstrates how to get the metadata for each message in a list of message IDs.

Note: This example requires Chilkat v11.0.0 or greater.

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

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#include <C_CkHttpW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkHttpResponseW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttpW http;
    HCkJsonObjectW jsonMsgIds;
    HCkHttpResponseW resp;
    const wchar_t *id;
    int i;
    int count_i;
    HCkJsonObjectW jsonResponse;

    success = FALSE;

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

    http = CkHttpW_Create();

    CkHttpW_putAuthToken(http,L"ACCESS_TOKEN");

    CkHttpW_putAccept(http,L"application/json");

    // Let's say we have the following JSON containing a list of message ID's

    // {
    //   "messages": [
    //     {
    //       "id": "1712bc1dc22da2a2",
    //       "threadId": "1712bc1dc22da2a2"
    //     },
    //     {
    //       "id": "1712b94fa2168040",
    //       "threadId": "1712b94fa2168040"
    //     },
    //     {
    //       "id": "1711e4bd96ded05e",
    //       "threadId": "1711e4bd96ded05e"
    //     },
    //     {
    //       "id": "1711de0d119e751e",
    //       "threadId": "1711de0d119e751e"
    //     },
    //     {
    //       "id": "1711c81a43050f59",
    //       "threadId": "1711c81a43050f59"
    //     },
    //     {
    //       "id": "1711c2c1516abce5",
    //       "threadId": "1711c2c1516abce5"
    //     },
    //     {
    //       "id": "1711c161e655c915",
    //       "threadId": "1711c161e655c915"
    //     },
    //     {
    //       "id": "171199c6e454558c",
    //       "threadId": "171199c6e454558c"
    //     },
    //     {
    //       "id": "17119474c8aa248e",
    //       "threadId": "17119474c8aa248e"
    //     }
    //   ],
    //   "nextPageToken": "16710921492249671162",
    //   "resultSizeEstimate": 309
    // }

    // Normally your program would have the above JSON in a string variable (obtained from a previous call to get
    // a list of message IDs from a GMail mailbox).  In this example, we'll load the JSON from a file.
    jsonMsgIds = CkJsonObjectW_Create();
    success = CkJsonObjectW_LoadFile(jsonMsgIds,L"qa_data/json/gmail_message_ids.json");

    resp = CkHttpResponseW_Create();

    i = 0;
    count_i = CkJsonObjectW_SizeOfArray(jsonMsgIds,L"messages");
    while (i < count_i) {
        CkJsonObjectW_putI(jsonMsgIds,i);
        id = CkJsonObjectW_stringOf(jsonMsgIds,L"messages[i].id");

        // Get the metadata for this message ID.
        CkHttpW_SetUrlVar(http,L"id",id);

        success = CkHttpW_HttpNoBody(http,L"GET",L"https://www.googleapis.com/gmail/v1/users/userId/messages/{$id}?format=metadata",resp);
        if (success == FALSE) {
            wprintf(L"%s\n",CkHttpW_lastErrorText(http));
            CkHttpW_Dispose(http);
            CkJsonObjectW_Dispose(jsonMsgIds);
            CkHttpResponseW_Dispose(resp);
            return;
        }

        wprintf(L"Response Status Code: %d\n",CkHttpResponseW_getStatusCode(resp));

        jsonResponse = CkJsonObjectW_Create();
        CkJsonObjectW_Load(jsonResponse,CkHttpResponseW_bodyStr(resp));
        CkJsonObjectW_putEmitCompact(jsonResponse,FALSE);
        wprintf(L"%s\n",CkJsonObjectW_emit(jsonResponse));

        if (CkHttpResponseW_getStatusCode(resp) != 200) {
            wprintf(L"Failed.\n");
            CkHttpW_Dispose(http);
            CkJsonObjectW_Dispose(jsonMsgIds);
            CkHttpResponseW_Dispose(resp);
            CkJsonObjectW_Dispose(jsonResponse);
            return;
        }

        i = i + 1;
    }

    // Use this online tool to generate parsing code from sample JSON: 
    // Generate Parsing Code from JSON


    CkHttpW_Dispose(http);
    CkJsonObjectW_Dispose(jsonMsgIds);
    CkHttpResponseW_Dispose(resp);
    CkJsonObjectW_Dispose(jsonResponse);

    }