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 <CkHttpW.h>
#include <CkStringBuilderW.h>
#include <CkJsonObjectW.h>
#include <CkHttpResponseW.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkHttpW http;
    http.put_AuthToken(L"GMAIL-ACCESS-TOKEN");

    const wchar_t *userId = L"me";
    http.SetUrlVar(L"userId",userId);

    const wchar_t *query = L"subject:questions";
    http.SetUrlVar(L"query",query);

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

    CkStringBuilderW sb;
    success = http.QuickGetSb(url,sb);
    if (success == false) {
        wprintf(L"%s\n",http.lastErrorText());
        return;
    }

    CkJsonObjectW json;
    json.LoadSb(sb);
    json.put_EmitCompact(false);
    wprintf(L"%s\n",json.emit());

    if (http.get_LastStatus() != 200) {
        wprintf(L"Failed.\n");
        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.

    CkJsonObjectW json2;

    int i = 0;
    int numMessages = json.SizeOfArray(L"messages");
    while ((i < numMessages)) {
        json.put_I(i);
        const wchar_t *id = json.stringOf(L"messages[i].id");
        json2.put_I(i);
        json2.UpdateString(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"
    const wchar_t *labelId = L"Label_43";
    json2.UpdateString(L"addLabelIds[0]",labelId);
    json2.UpdateNewArray(L"removeLabelIds");

    json2.put_EmitCompact(false);
    wprintf(L"%s\n",json2.emit());

    // Send the batchModify
    url = L"https://www.googleapis.com/gmail/v1/users/{$userId}/messages/batchModify";
    CkHttpResponseW resp;
    success = http.HttpJson(L"POST",url,json2,L"application/json",resp);
    if (success == false) {
        wprintf(L"%s\n",http.lastErrorText());
        return;
    }

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

    // A 204 response status indicate success.
    if (resp.get_StatusCode() != 204) {
        wprintf(L"%s\n",resp.bodyStr());
        wprintf(L"Failed.\n");
        return;
    }

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

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