Sample code for 30+ languages & platforms
Unicode C

BatchModify - Add a Label to each Message in Search Results

See more GMail REST API Examples

Searchs GMail for messages meeting a criteria and adds a label to each message found.

Chilkat Unicode C Downloads

Unicode C
#include <C_CkHttpW.h>
#include <C_CkStringBuilderW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkHttpResponseW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttpW http;
    const wchar_t *userId;
    const wchar_t *query;
    const wchar_t *url;
    HCkStringBuilderW sb;
    HCkJsonObjectW json;
    HCkJsonObjectW json2;
    int i;
    int numMessages;
    const wchar_t *id;
    const wchar_t *labelId;
    HCkHttpResponseW resp;

    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"GMAIL-ACCESS-TOKEN");

    userId = L"me";
    CkHttpW_SetUrlVar(http,L"userId",userId);

    query = L"subject:questions";
    CkHttpW_SetUrlVar(http,L"query",query);

    url = L"https://www.googleapis.com/gmail/v1/users/{$userId}/messages?q={$query}";

    sb = CkStringBuilderW_Create();
    success = CkHttpW_QuickGetSb(http,url,sb);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkHttpW_Dispose(http);
        CkStringBuilderW_Dispose(sb);
        return;
    }

    json = CkJsonObjectW_Create();
    CkJsonObjectW_LoadSb(json,sb);
    CkJsonObjectW_putEmitCompact(json,FALSE);
    wprintf(L"%s\n",CkJsonObjectW_emit(json));

    if (CkHttpW_getLastStatus(http) != 200) {
        wprintf(L"Failed.\n");
        CkHttpW_Dispose(http);
        CkStringBuilderW_Dispose(sb);
        CkJsonObjectW_Dispose(json);
        return;
    }

    // If successful, the received JSON looks like this:
    // {
    //   "messages": [
    //     {
    //       "id": "166f583051d36144",
    //       "threadId": "166f583051d36144"
    //     },
    //     {
    //       "id": "166f5815e1f36144",
    //       "threadId": "166f5815e1f36144"
    //     },
    // 	...
    //     {
    //       "id": "166f580639e36144",
    //       "threadId": "166f580639e36144"
    //     },
    //     {
    //       "id": "15dbc2e28ec789c6",
    //       "threadId": "15dbc2e28ec789c6"
    //     }
    //   ],
    //   "nextPageToken": "13434766102274844688",
    //   "resultSizeEstimate": 103
    // }
    // 

    // Next, we'll be sending an HTTP POST to add the label "questions" to each message in the
    // search results.  The JSON to be sent for the batchModify is this:

    // 	{
    // 	  "ids": [
    // 	    string
    // 	  ],
    // 	  "addLabelIds": [
    // 	    string
    // 	  ],
    // 	  "removeLabelIds": [
    // 	    string
    // 	  ]
    // 	}

    // We'll omit "removeLabelIds" because we're not removing any labels.
    // We are parsing the JSON search results, and at the same time building the batchModify JSON.

    json2 = CkJsonObjectW_Create();

    i = 0;
    numMessages = CkJsonObjectW_SizeOfArray(json,L"messages");
    while ((i < numMessages)) {
        CkJsonObjectW_putI(json,i);
        id = CkJsonObjectW_stringOf(json,L"messages[i].id");
        CkJsonObjectW_putI(json2,i);
        CkJsonObjectW_UpdateString(json2,L"ids[i]",id);
        i = i + 1;
    }

    // We need the id of the label (not the name).
    // I know the name of the label is "questions", but I need to know the id.
    // See this example: Get Label Id by Name
    // The id of my label named "questions" is "Label_43"
    labelId = L"Label_43";
    CkJsonObjectW_UpdateString(json2,L"addLabelIds[0]",labelId);
    CkJsonObjectW_UpdateNewArray(json2,L"removeLabelIds");

    CkJsonObjectW_putEmitCompact(json2,FALSE);
    wprintf(L"%s\n",CkJsonObjectW_emit(json2));

    // Send the batchModify
    url = L"https://www.googleapis.com/gmail/v1/users/{$userId}/messages/batchModify";
    resp = CkHttpResponseW_Create();
    success = CkHttpW_HttpJson(http,L"POST",url,json2,L"application/json",resp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkHttpW_Dispose(http);
        CkStringBuilderW_Dispose(sb);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(json2);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    wprintf(L"status = %d\n",CkHttpResponseW_getStatusCode(resp));

    // A 204 response status indicate success.
    if (CkHttpResponseW_getStatusCode(resp) != 204) {
        wprintf(L"%s\n",CkHttpResponseW_bodyStr(resp));
        wprintf(L"Failed.\n");
        CkHttpW_Dispose(http);
        CkStringBuilderW_Dispose(sb);
        CkJsonObjectW_Dispose(json);
        CkJsonObjectW_Dispose(json2);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    // The 204 response has an empty response body..

    wprintf(L"BatchModify success!\n");


    CkHttpW_Dispose(http);
    CkStringBuilderW_Dispose(sb);
    CkJsonObjectW_Dispose(json);
    CkJsonObjectW_Dispose(json2);
    CkHttpResponseW_Dispose(resp);

    }