multipart_form.dart

import 'dart:async';
import 'dart:convert';
import 'package:mime/mime.dart';
import 'package:sv_rent_car/src/services/data_contract_service.dart';
import 'package:sv_rent_car/sv_rent_car.dart';

class MultiPartFormDataParser{
  
  static Future<Object> multiPartData({Request request, Object object, String folder, Function onTextData, Function onFileData}) async {
    final transformer = MimeMultipartTransformer(request.raw.headers.contentType.parameters["boundary"]);
    final parts = await transformer.bind(Stream.fromIterable([await request.body.decode<List<int>>()])).toList();  
    for (var part in parts) {
      final multipart = HttpMultipartFormData.parse(part);
      try{
        if(multipart.isText)
          onTextData(await multipart);
        else{
          final ContentType contentType = multipart.contentType;
          final content = multipart.cast<List<int>>();
          
          final fileName = fileNameGenerator(multipart.contentDisposition.parameters.values.first, contentType.subType.split('/').last);
          onFileData(await multipart, '$folder/$fileName');
                    
          final IOSink sink = File('$folder/$fileName').openWrite();
          await for (List<int> item in content) {
            sink.add(item);
          };
          await sink.flush();
          await sink.close();
        }
      }catch(e){
        print("MultipartFormData Exception : \n ${e}");
      }
    }
    return object;
  }

  static String fileNameGenerator(String filename, String extension){
    final str = "${DateTime.now().toIso8601String()}$filename";
    final bytes = utf8.encode(str);
    final base64Str = base64.encode(bytes);
    return  '$base64Str.$extension';
  }
  
}