Sample code for 30+ languages & platforms
Objective-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 Objective-C Downloads

Objective-C
#import <CkoHttp.h>
#import <NSString.h>
#import <CkoStringBuilder.h>
#import <CkoJsonObject.h>
#import <CkoHttpResponse.h>

BOOL success = NO;

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

CkoHttp *http = [[CkoHttp alloc] init];
http.AuthToken = @"GMAIL-ACCESS-TOKEN";

NSString *userId = @"me";
[http SetUrlVar: @"userId" value: userId];

NSString *query = @"subject:questions";
[http SetUrlVar: @"query" value: query];

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

CkoStringBuilder *sb = [[CkoStringBuilder alloc] init];
success = [http QuickGetSb: url sbContent: sb];
if (success == NO) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

CkoJsonObject *json = [[CkoJsonObject alloc] init];
[json LoadSb: sb];
json.EmitCompact = NO;
NSLog(@"%@",[json Emit]);

if ([http.LastStatus intValue] != 200) {
    NSLog(@"%@",@"Failed.");
    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.

CkoJsonObject *json2 = [[CkoJsonObject alloc] init];

int i = 0;
int numMessages = [[json SizeOfArray: @"messages"] intValue];
while ((i < numMessages)) {
    json.I = [NSNumber numberWithInt: i];
    NSString *id = [json StringOf: @"messages[i].id"];
    json2.I = [NSNumber numberWithInt: i];
    [json2 UpdateString: @"ids[i]" value: 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"
NSString *labelId = @"Label_43";
[json2 UpdateString: @"addLabelIds[0]" value: labelId];
[json2 UpdateNewArray: @"removeLabelIds"];

json2.EmitCompact = NO;
NSLog(@"%@",[json2 Emit]);

// Send the batchModify
url = @"https://www.googleapis.com/gmail/v1/users/{$userId}/messages/batchModify";
CkoHttpResponse *resp = [[CkoHttpResponse alloc] init];
success = [http HttpJson: @"POST" url: url json: json2 contentType: @"application/json" response: resp];
if (success == NO) {
    NSLog(@"%@",http.LastErrorText);
    return;
}

NSLog(@"%@%d",@"status = ",[resp.StatusCode intValue]);

// A 204 response status indicate success.
if ([resp.StatusCode intValue] != 204) {
    NSLog(@"%@",resp.BodyStr);
    NSLog(@"%@",@"Failed.");
    return;
}

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

NSLog(@"%@",@"BatchModify success!");