Flutter Dio 라이브러리란?

Dio 라이브러리란?

• Flutter 프레임워크 환경에서 HTTP 요청을 할 때 유용하게 쓰이는 라이브러리이다.
• 웹에서 쓰는 범용 Fetch 라이브러리들과 비슷한 기능을 제공한다.
  • Global configuration
  • Interceptors
  • FormData
  • Request cancellation
  • File uploading/downloading
  • Timeout
  • Custom adapters
  • Transformer

기본 사용법

import 'package:dio/dio.dart';

final dio = Dio();

void request() async {
  Response response;
  response = await dio.get('/test?id=12&name=dio');
  print(response.data.toString());
  // The below request is the same as above.
  response = await dio.get(
    '/test',
    queryParameters: {'id': 12, 'name': 'dio'},
  );
  print(response.data.toString());
}

요청 옵션

/// Http method.
String method;

/// Request base url, it can contain sub path, like: https://dart.dev/api/.
String? baseUrl;

/// Http request headers.
Map<String, dynamic>? headers;

/// Timeout for opening url.
Duration? connectTimeout;

/// Whenever more than [receiveTimeout] passes between two events from response stream,
/// [Dio] will throw the [DioException] with [DioExceptionType.RECEIVE_TIMEOUT].
/// Note: This is not the receiving time limitation.
Duration? receiveTimeout;

/// Request data, can be any type.
dynamic data;

/// If the `path` starts with 'http(s)', the `baseURL` will be ignored, otherwise,
/// it will be combined and then resolved with the baseUrl.
String path;

/// The request Content-Type.
///
/// The default `content-type` for requests will be implied by the
/// [ImplyContentTypeInterceptor] according to the type of the request payload.
/// The interceptor can be removed by
/// [Interceptors.removeImplyContentTypeInterceptor].
///
/// If you want to encode request body with 'application/x-www-form-urlencoded',
/// you can set [Headers.formUrlEncodedContentType], and [Dio]
/// will automatically encode the request body.
String? contentType;

/// [responseType] indicates the type of data that the server will respond with
/// options which defined in [ResponseType] are `json`, `stream`, `plain`.
///
/// The default value is `json`, dio will parse response string to json object automatically
/// when the content-type of response is 'application/json'.
///
/// If you want to receive response data with binary bytes, for example,
/// downloading a image, use `stream`.
///
/// If you want to receive the response data with String, use `plain`.
ResponseType? responseType;

/// `validateStatus` defines whether the request is successful for a given
/// HTTP response status code. If `validateStatus` returns `true` ,
/// the request will be perceived as successful; otherwise, considered as failed.
ValidateStatus? validateStatus;

/// Custom field that you can retrieve it later in [Interceptor],
/// [Transformer] and the [Response.requestOptions] object.
Map<String, dynamic>? extra;

/// Common query parameters.
Map<String, dynamic /*String|Iterable<String>*/ >? queryParameters;

/// [listFormat] indicates the format of collection data in request options。
/// The default value is `multiCompatible`
ListFormat? listFormat;

응답

/// Response body. may have been transformed, please refer to [ResponseType].
T? data;

/// The corresponding request info.
RequestOptions requestOptions;

/// HTTP status code.
int? statusCode;

/// Returns the reason phrase associated with the status code.
/// The reason phrase must be set before the body is written
/// to. Setting the reason phrase after writing to the body.
String? statusMessage;

/// Whether this response is a redirect.
/// ** Attention **: Whether this field is available depends on whether the
/// implementation of the adapter supports it or not.
bool isRedirect;

/// The series of redirects this connection has been through. The list will be
/// empty if no redirects were followed. [redirects] will be updated both
/// in the case of an automatic and a manual redirect.
///
/// ** Attention **: Whether this field is available depends on whether the
/// implementation of the adapter supports it or not.
List<RedirectRecord> redirects;

/// Custom fields that only for the [Response].
Map<String, dynamic> extra;

/// Response headers.
Headers headers;

여러 요청을 한번에 하고 싶을 때

response = await Future.wait([dio.post('/info'), dio.get('/token')]);

파일을 다운로드 받을 때

response = await dio.download(
  'https://pub.dev/',
  (await getTemporaryDirectory()).path + 'pub.html',
);

응답 스트림을 받을 때

final rs = await dio.get(
  url,
  options: Options(responseType: ResponseType.stream), // Set the response type to `stream`.
);

print(rs.data.stream); // Response stream.

bytes 로 응답을 받을 때

final rs = await Dio().get<List<int>>(
  url,
  options: Options(responseType: ResponseType.bytes), // Set the response type to `bytes`.
);

print(rs.data); // Type: List<int>.

FormData 를 보내야 할 때

final formData = FormData.fromMap({
  'name': 'dio',
  'date': DateTime.now().toIso8601String(),
});

final response = await dio.post('/info', data: formData);

여러 파일을 업로드할 때

final formData = FormData.fromMap({
  'name': 'dio',
  'date': DateTime.now().toIso8601String(),
  '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'),
  ]
});

final response = await dio.post('/info', data: formData);

업로드 진행상황을 리스닝할 때

final response = await dio.post(
  'https://www.dtworkroom.com/doris/1/2.0.0/test',
  data: {'aa': 'bb' * 22},
  onSendProgress: (int sent, int total) {
    print('$sent $total');
  },
);

바이너리 데이터를 스트림으로 보낼 때

// Binary data
final postData = <int>[0, 1, 2];
await dio.post(
  url,
  data: Stream.fromIterable(postData.map((e) => [e])), // Creates a Stream<List<int>>.
  options: Options(
    headers: {
      Headers.contentLengthHeader: postData.length, // Set the content-length.
    },
  ),
);

공식 문서

https://pub.dev/packages/dio