flutter-handling-http-and-json

Add the http package to pubspec.yaml, build the URL with Uri.https, and call http.get, http.post, http.put, or http.delete. Validate response.statusCode for 200 or 201 before calling jsonDecode on the response body.

Move parsing to a background isolate using Flutter's compute() function. Define a top-level function that takes the response body string and returns parsed Dart objects, then pass it to compute() after receiving the HTTP response.

Use manual serialization with dart:convert for small prototypes or simple models. For production apps with complex or nested models, use json_serializable with build_runner to generate fromJson and toJson code automatically.

Android and iOS block cleartext HTTP connections by default, so use HTTPS endpoints. Also ensure the Internet permission is declared in AndroidManifest.xml and macOS entitlements are configured where applicable.

Call http.post with the target URI, set the Content-Type header to application/json; charset=UTF-8, and pass jsonEncode(yourMap) as the body. Treat a 201 status code as a successful creation response.