nuke

Description:

nuke

nuke #
Super slim, lightweight, practical state management < 250 lines of code.
[Not for the faint hearted, PRs super appreciated.]
To the point:
Counter app #
import 'package:nuke/nuke.dart';

class MyHomePage extends StatelessWidget
{
final counter = $rx(0, ref:'ref/0');

MyHomePage({Key key}) : super(key: key);

@override
Widget build(BuildContext context)
{
return Scaffold
(
body: Center
(
child: RX(const ['ref/:any'], (context) =>
Text(counter.value.toString()))
//alternatively $rx.$ref('ref/0').value
),
floatingActionButton: FloatingActionButton
(
onPressed: ()=>counter.value++,
//alternatively $rx.$ref('ref/0').value++
child: const Icon(Icons.add),
),
);
}
}
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Where's my state?
Hence the name.
Let's break it down:
final counter = $rx(0, ref:'ref/0');
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0 is our initial value
ref reference the observalbe value at 'ref/0'

//intentionally not named (aka matchers:[], builder:(context)) to keep it short
child: RX(const ['ref/:any'], (context) =>
Text($rx.$ref('ref/0').value.toString()))
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the observer widget name
a list of names / regex scopes the widget should listen to
$rx.$ref('ref/0').value obtain the value by reference

counter.value also works, the above used for illustation purposed.
More on matchers, consider this:
final counter1 = $rx(0, ref:'ref/0');
final counter2 = $rx(0, ref:'ref/1');

@override
Widget build(BuildContext context)=>
RX(const ['ref/0', 'ref/1'], (context)=>Container());
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The above widget will be rebuilt whenever either counter1 or counter2
change their values.
Alternatively:
@override
Widget build(BuildContext context)=>
RX(const ['ref/:idx'], (context)=>Container());
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References are awesome because they allow observers to be defined and acessed
anywhere within the app.
A practical example would be a "aettings" screen where value X is utilized within
the underlying widget, saving hassle of passing values between the two separate
widgets and updating each's local state.
Banana republic multi counter app #
class MyHomePage2 extends StatelessWidget
{
final counters = {
'x': 'y',
'a': {
'b': {
'c': $rx(0, ref:'counter/0'),
'wtf': [$rx(0, ref:'counter/1'), $rx(0, ref:'counter/2')],
},
}
};

int sum()=>
Iterable.generate(3).map((i)=>$rx.$ref('counter/$i').value as int)
.reduce((a,b )=>a+b);

void increment()=>
Iterable.generate(3).forEach((i)=>$rx.$ref('counter/$i').value++);

MyHomePage2({Key key}) : super(key: key);

@override
Widget build(BuildContext context)
{
return Scaffold
(
body: Center
(
child: Wrap(spacing:20, children:
[
//Listens to all observables on counter/:any
RX(const ['counter/:any'],(context) =>Text('${sum()}')),

//Listens only to counter/1
RX(const ['counter/1'], (context) => Text('${$rx.$ref('counter/1').value}')),

//Listens only to counter/2
RX(['counter/2'], (context) => Text('${$rx.$ref('counter/2').value}')),
],),
),
floatingActionButton: FloatingActionButton(
onPressed:increment, child: const Icon(Icons.add), ),
);
}
}
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Computed values #
final counter1 = $rx(0, ref:'ref/0');
final counter2 = $rx(0, ref:'ref/1');

final sum = $cmp(['ref/0', 'ref/1'],
()=>$rx.$ref('ref/0').value+$rx.$ref('ref/1').value, ref:'ref/sum')
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Tagging #
final counter1 = $rx(0, ref:'ref/0', tags:['dirty']);
final counter2 = $rx(0, ref:'ref/1', tags:['dirty']);

nuke.diposeTagged(['dirty', 'whatever'], matchAny:true)
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Clean up #
$RX automatically cleans up observable subscriptions, however, to dispose
observables that are no longer in use, call nuke.dispose([ref]).
Pub sub #
import 'package:nuke/nuke.dart';

final $n = Nuke();

//subscribe
final subKey = $n.subscribe(['topic'], (topic, data)=>print(data));

//publish
$n.publish('topic', {'foo':1});

//unsubscribe
$n.unsubscribe(subKey);
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What's up with the $ #
Just to avoid accedential conflicts and keep name conventions short.