Flutter http sending list value in the body in a post multipart request

Issue

I am trying to send a multipart post request to upload images and sending some other data in flutter with a body looks like this

bodyMap = {
  'type' : 'text',
  'content': [
     {
        'type': image'
        'identifier: '1234'
     }
   ]
};

However when I'm trying to add it to the request like this

var request = http.MultipartRequest('POST', Uri.parse(url));
request.fields.addAll(bodyMap);

it refuses to add it as it only accepts Map<String, String>

how to solve this problem?

Solution

I have found that Dio Package allows you to post a map of type Map<String,Dynamic> with multipart post request, for example:

var formData = FormData.fromMap({
  'name': 'wendux',
  'age': 25,
  'file': await MultipartFile.fromFile('./text.txt', filename: 'upload.txt'),
  'files': [
    await MultipartFile.fromFile('./text1.txt', filename: 'text1.txt'),
    await MultipartFile.fromFile('./text2.txt', filename: 'text2.txt'),
  ]
});
var response = await dio.post('/info', data: formData);

Answered By - Ammar Mohamed