flutter-implement-json-serialization

Use the built-in dart:convert library with jsonDecode to parse the response body, cast the result to Map<String, dynamic>, and pass it to a fromJson factory constructor on your model class. Implement a toJson method for serialization.

Define a factory constructor Model.fromJson(Map<String, dynamic> json) that extracts and casts values, optionally using Dart pattern matching. Write a toJson method returning a Map<String, dynamic> that maps properties back to their JSON string keys.

Use compute() when parsing large JSON documents that take longer than 16ms, such as arrays of thousands of objects. It runs the parsing function in a background isolate, preventing UI jank on the main thread.

No, dart:convert is built into the Dart SDK and provides jsonEncode and jsonDecode. You only need the http package for network requests; serialization itself works without third-party dependencies.

jsonDecode returns dynamic, so using values without casting causes runtime type errors. Always cast to Map<String, dynamic> for objects or List<dynamic> for arrays, and use pattern matching or explicit casts in fromJson.

Manual serialization requires writing boilerplate for every model and maintaining it when APIs change. For complex or deeply nested structures, code generation approaches may reduce maintenance effort compared to hand-written fromJson and toJson methods.