learn.dart+flutter shafi.dev

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Goal

Know why teams generate serialization code without adopting a tool in this level.

What codegen usually solves

  • Large models with many fields: hand-written fromJson drifts from APIs.
  • Consistent rules for null, defaults, renaming keys (@JsonKey(name: 'user_id')), and enums.

Common stack in Dart

  • Package json_annotation marks models with annotations.
  • Package json_serializable plus build_runner generates *.g.dart files with fromJson/toJson implementations.

Typical workflow (overview)

  • Add dev dependencies: build_runner, json_serializable, and json_annotation.
  • Run dart run build_runner build after changing annotated classes.
  • Commit generated files if your team policy requires reproducible builds.

When manual JSON is enough

  • Learning exercises, tiny DTOs, scripts, and prototypes.
  • Full control over error messages and partial parsing.

Practice tasks

  • Skim the json_serializable readme on pub.dev and list three annotations or options you noticed.
  • Keep your Week 7 project manual; note one model that would be painful to maintain by hand at 30+ fields.