dispose_all 1.0.0+1

A Flutter package for reducing boilerplate code when disposing of objects

A Flutter package that introduces a convenient way to dispose of objects.

Features

• DisposableObject mixin. Makes any your custom class, or a class which was implemented in another package, usable (and disposable) with this package
• disposeAll method for Iterable that disposes of every item of that Iterable. The elements can be:
  • DisposableObject, obviously
  • ChangeNotifier and anything that extends or uses it as a mixin, e.g. TextEditingController, FocusNode, ScrollController and much more
  • Sink, e.g. StreamController
  • StreamSubscription
  • Timer
  • AnimationEagerListenerMixin, e.g. AnimationController

Usage

Disposing of a list of objects

Define objects that must be disposed of later:

final textEditingController = TextEditingController();
final focusNode = FocusNode();
final stream = StreamController.broadcast();
final listener = someStream.listen(...);
final timer = Timer.periodic(...);
final animationController = AnimationController(...);

Put them all in an Iterable:

final disposables = [
  textEditingController,
  focusNode,
  stream,
  listener,
  timer,
  animationController,
];

Dispose of all objects when they are no longer needed:

disposables.disposeAll();

Make custom class disposable

Custom classes instances cannot be disposed of by using disposeAll() method by default. Luckily, there's an easy way to add such functionality to any class by DisposableObject mixin:

class DisposableTest with DisposableObject {
  bool disposed = false; // or anything you need

  @override
  void disposeObject() {
    disposed = true; // or anything you'd like to do
  }
}

Now DisposableTest objects can be disposed of by disposeAll method:

final myDisposable = DisposableTest();
...
[
  myDisposable,
  ...
].disposeAll();

Let's say you use Dio package for handling http requests. You might be using CancelToken objects to cancel http requests when you leave a page before http request is finished. Calling disposeAll method on a list, where one of the elements is CancelToken will lead to throwing UnimplementedError. But you can easily make a wrapper for CancelToken to make things working:

import 'package:dio/dio.dart';

class CancelTokenDisposable extends CancelToken with DisposableObject {
  @override
  void disposeObject() {
    cancel();
  }
}

Now CancelTokenDisposable instances can be disposed of by disposeAll method:

class _MyWidgetState extends State<MyWidget> {
  List _disposables = [];

  CancelTokenDisposable cancelToken = CancelTokenDisposable();

  @override
  void initState() {
    super.initState();
    _disposables = [
      cancelToken,
      ...
    ];
  }

  @override
  Widget build(BuildContext context) {
    ...
  }

  @override
  void dispose() {
    _disposables.disposeAll();
    super.dispose();
  }
}

Contribution

Please feel free to open an issue on GitHub, if you feel like this package misses some functionality required for your project.