Dart

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. Dart

import 'package:chilkat/chilkat.dart';

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

  final http = CkHttp();
  http.authToken = 'GMAIL-ACCESS-TOKEN';

  final userId = 'me';
  http.setUrlVar('userId', userId);

  final query = 'subject:questions';
  http.setUrlVar('query', query);

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

  final sb = CkStringBuilder();
  try {
    http.quickGetSb(url, sb);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  final json = CkJsonObject();
  json.loadSb(sb);
  json.emitCompact = false;
  print(json.emit());

  if (http.lastStatus != 200) {
    print('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.

  final json2 = CkJsonObject();

  var i = 0;
  final numMessages = json.sizeOfArray('messages');
  while (i < numMessages) {
    json.i = i;
    final id = json.stringOf('messages[i].id');
    json2.i = i;
    json2.updateString('ids[i]', id);
    i++;
  }

  // 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"
  final labelId = 'Label_43';
  json2.updateString('addLabelIds[0]', labelId);
  json2.updateNewArray('removeLabelIds');

  json2.emitCompact = false;
  print(json2.emit());

  // Send the batchModify
  url = 'https://www.googleapis.com/gmail/v1/users/{\$userId}/messages/batchModify';
  final resp = CkHttpResponse();
  try {
    http.httpJson('POST', url, json2, 'application/json', resp);
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print('status = ${resp.statusCode}');

  // A 204 response status indicate success.
  if (resp.statusCode != 204) {
    print(resp.bodyStr);
    print('Failed.');
    return;
  }

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

  print('BatchModify success!');
}