Sample code for 30+ languages & platforms
C

Find a Label ID by Name

See more GMail REST API Examples

Lookup the ID of a GMail label by the label name.

Chilkat C Downloads

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

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttp http;
    const char *userId;
    const char *url;
    HCkStringBuilder sb;
    HCkJsonObject json;
    HCkJsonObject jRecord;

    success = FALSE;

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

    http = CkHttp_Create();
    CkHttp_putAuthToken(http,"GMAIL-ACCESS-TOKEN");

    userId = "me";
    CkHttp_SetUrlVar(http,"userId",userId);

    url = "https://www.googleapis.com/gmail/v1/users/{$userId}/labels";

    //  Get the list of GMail labels as JSON.
    sb = CkStringBuilder_Create();
    success = CkHttp_QuickGetSb(http,url,sb);
    if (success != TRUE) {
        printf("%s\n",CkHttp_lastErrorText(http));
        CkHttp_Dispose(http);
        CkStringBuilder_Dispose(sb);
        return;
    }

    json = CkJsonObject_Create();
    CkJsonObject_LoadSb(json,sb);
    CkJsonObject_putEmitCompact(json,FALSE);
    printf("%s\n",CkJsonObject_emit(json));

    if (CkHttp_getLastStatus(http) != 200) {
        printf("Failed.\n");
        CkHttp_Dispose(http);
        CkStringBuilder_Dispose(sb);
        CkJsonObject_Dispose(json);
        return;
    }

    //  The JSON returned looks like this:
    //  {
    //    "labels": [
    //      {
    //        "id": "Label_5",
    //        "name": "QA",
    //        "messageListVisibility": "show",
    //        "labelListVisibility": "labelShow",
    //        "type": "user"
    //      },
    //      {
    //        "id": "Label_21",
    //        "name": "[Gmail]/testFolder",
    //        "type": "user"
    //      },
    //      {
    //        "id": "CATEGORY_PERSONAL",
    //        "name": "CATEGORY_PERSONAL",
    //        "type": "system"
    //      },
    //  	...

    //  The name of the label is generally known because it's what we visually see.
    //  The id is what we need to get.  Assuming the name is unique,
    //  find the JSON record having name=<desired name>
    //  For example...
    jRecord = CkJsonObject_FindRecord(json,"labels","name","QA",FALSE);
    if (CkJsonObject_getLastMethodSuccess(json) == TRUE) {
        printf("The id of QA is: %s\n",CkJsonObject_stringOf(jRecord,"id"));
        CkJsonObject_Dispose(jRecord);
    }

    jRecord = CkJsonObject_FindRecord(json,"labels","name","[Gmail]/testFolder",FALSE);
    if (CkJsonObject_getLastMethodSuccess(json) == TRUE) {
        printf("The id of [Gmail]/testFolder is: %s\n",CkJsonObject_stringOf(jRecord,"id"));
        CkJsonObject_Dispose(jRecord);
    }

    jRecord = CkJsonObject_FindRecord(json,"labels","name","questions",FALSE);
    if (CkJsonObject_getLastMethodSuccess(json) == TRUE) {
        printf("The id of questions is: %s\n",CkJsonObject_stringOf(jRecord,"id"));
        CkJsonObject_Dispose(jRecord);
    }

    //  Output:

    //  The id of QA is: Label_5
    //  The id of [Gmail]/testFolder is: Label_21
    //  The id of questions is: Label_43


    CkHttp_Dispose(http);
    CkStringBuilder_Dispose(sb);
    CkJsonObject_Dispose(json);

    }