state_tools 1.2.3

A light and simple State Manager for Flutter Apps.

State Tools

A light and simple State Manager for Flutter Apps.

How Simple?

1. Create your StateNotifier class:

class CounterState extends StateNotifier<int> {
  CounterState() : super(0);
  
  void increment() => state += 1;
}

if you want a specialized type for Lists:

class CounterState extends ListStateNotifier<int> {
  CounterState() : super(List.empty());

  void push(int value) => add(value * 2);

  @override
  bool filter(int value) => value % 2 == 0;
}

You can apply a filter for items on list (not mandatory).
This filter will be applied every time the list value change.

Also, the ListStateNotifier offers prebuilt helper modifiers, like:

• add(item)
• removeFist(item)
• addAll([ list of items ])
• removeAll([ list of items ])

2. On your Widget use a StateBuilder to interact with your StateNotifier

StateBuilder<int>(
  notifier: counterStateInstance,
  builder: (context, state) => Text('$state')
)

...

FloatingActionButton(
  onPressed: () => counterStateInstance.increment(),
  tooltip: 'Increment',
  child: const Icon(Icons.add),
)

Or... you can just listen the changes and do your Non-UI related logic:

StateListener<int>(
  notifier: counterStateInstance,
  listener: (context, state) => log('$state'),
  child: const Text('My StateListener')
)

Since version 1.1.0, it's possible to build and to listen more than just one state at same time, with DoubleStateBuilder, DoubleStateListener, TripleStateBuilder and TripleStateListener:

DoubleStateBuilder<int, String>(
  notifier1: counterStateInstance,
  notifier2: textStateInstance,
  builder: (context, counter, text) => Text('$state : $text')
)

...

TripleStateListener<int, String, bool>(
  notifier1: counterStateInstance,
  notifier2: textStateInstance,
  notifier3: boolStateInstance,
  listener: (context, counter, text, boolValue) => log('$state : $text : $boolValue'),
  child: const Text('My TripleStateListener')
)

Want More?

For persistent states, use the PersistableStateNotifier

class CounterState extends PersistableStateNotifier<int> {
  CounterState() : super(0);
     
  void increment() => state += 1;

  @override
  int fromJson(Map<String, dynamic> json) => json['value'] as int;
  
  @override
  Map<String, int> toJson(int state) => {'value': state};
}

For lists support, use the ListingSupport mixin

class FruitsState extends PersistableStateNotifier<String> with ListingSupport {
  FruitsState() : super('');

  @override
  String getListItemId(String state) => state;

  @override
  String get id => state;

  @override
  Map<String, dynamic> toJson(String state) => {'value': state};

  @override
  String fromJson(Map<String, dynamic> json) => json['value'] as String;
}

Attention:** The ListingSupport mixin requires the PersistableStateNotifier to be implemented and getListItemId for new entries on the list.

Also, the ListingSupport offers prebuilt helper modifiers, like:

• listLength
• first
• last
• list
• snapshot
• remove(id)
• clear

Interested?

Add state_tools package on your App:

state_tools: 1.2.2

License

Copyright 2024 TMApps

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.