Flutter Dio post an object with array

Question

I am trying to post a request to api with an object as"

var params =  {
    "item": "itemx",
    "options": [1,2,3],
    };
    print(params);
    try {
      Response response = await _dio.post(getAddToCartURL,
          queryParameters: params,
          options: Options(headers: {
            HttpHeaders.contentTypeHeader: "application/json",
          }));

    } catch (error, stackTrace) {
      print("Exception occurred: $error  stackTrace: $stackTrace");
      return false;
    }

Dio sends the object as :

POST /api/add-to-cart/?item=itemx&options%5B%5D=1&options%5B%5D=2&options%5B%5D=3

in which the api recognize it as a bad request.

what is wrong that i am doing here? I have even tried the list as [ "1","2","3"], it is the same.

dumazy · Accepted Answer · 2020-05-01 13:12:11Z

33

It all depends on how the API expects it. I would suggest trying to encode it as JSON.

var params =  {
  "item": "itemx",
  "options": jsonEncode([1,2,3]),
};

But sending complex data in query parameters isn't always that easy. Since you are using POST anyway, maybe send a JSON object as body instead of using query parameters.

var params =  {
  "item": "itemx",
  "options": [1,2,3],
}; 
...
Response response = await _dio.post(getAddToCartURL,
  options: Options(headers: {
    HttpHeaders.contentTypeHeader: "application/json",
  }),
  data: jsonEncode(params),
);

answered May 1, 2020 at 13:12

dumazy

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6 Comments

Chosen Over a year ago

thanks for the hint, it actually worked. I thought sending params as an object is enough but as i tried sending authentication params to the same api. Thanks

Prabudda Fernando Over a year ago

cant we send this type of array in get method?

dumazy Over a year ago

GET requests don't have a body and the data has to be put in URL parameters. In general that can be tricky, but it's definitely possible. The first code snippet suggests a way of using GET, the second snippet is for using POST which would generally be the better option but you need to change this on server side as well

Rahul Kushwaha Over a year ago

good example...

Kurt Over a year ago

Hi there, I tried this sample code in dio^4.0.6, but I couldn't receive data in my server. Other way I tried @AmirahmadAdibi 's answer and it works. Is this caused by dio version?

|

AmirahmadAdibi · Accepted Answer · 2022-07-03 08:55:30Z

0

another example for any one might be helpful , posting fomr data

            var formData = FormData.fromMap({
              'data': json.encode(
                  {'salt': salt, 'placeholder': 'palceholder', 
                  'method_name': 'app_details'})
            });

            var response = await dio.post(
              BaseUrl,
              data: formData,
            );

the final result of your request is this

answered Jul 3, 2022 at 8:55

AmirahmadAdibi

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Comments

Krishnanunni K A · Accepted Answer · 2025-08-12 02:14:57Z

0

    Future<void> createPost() async {
      try {
        final response = await dio.post(
          'https://jsonplaceholder.typicode.com/posts', // Replace with your API endpoint
          data: {
            'title': 'My New Post',
            'body': 'This is the content of my new post.',
            'userId': 1,
          },
        );
        print('Post created successfully: ${response.data}');
      } on DioException catch (e) {
        if (e.response != null) {
          print('Dio error!');
          print('STATUS: ${e.response?.statusCode}');
          print('DATA: ${e.response?.data}');
          print('HEADERS: ${e.response?.headers}');
        } else {
          // Error due to setting up or sending the request
          print('Error sending request: ${e.message}');
        }
      }
    }

answered Aug 12 at 2:14

Krishnanunni K A

1

1 Comment

Community Aug 12 at 2:17

As it’s currently written, your answer is unclear. Please edit to add additional details that will help others understand how this addresses the question asked. You can find more information on how to write good answers in the help center.

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