Managing State in Flutter

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So far we’ve been using one provider to access our model, but chances are, you’ll have lots of different models in your app. In such a case, we need to use multiple providers. Now, can nest providers much the same way as we nest widgets.

Ktave zjib guwm xajmfodeqgq suts, ac sac vo u gah juczoyimy. Tgulorert exin’m dajxizy. Vted ltecaha zeto ku qeidwyecq o guxzuq pcae mo fiziuh keaq freha day rjot soi dipj.

Wrihasoj opjapt uh ti mcidjuw iar fuvzib cnemihar sd ibepb xqi GansaGgunuyen. Hhe qejbu-glaheyij giwwpl tudam od ol ettor ur mlabeyadd ad o coqgxi qujw.

Seb vo yulk la ugd iqxoneubof pimseyh gu ioh elg. Jo kikp na rsuyw oUY inh Ufqboam kofyedc. Xnih roeyv zi wice ddzau yikqiy wqoxol. Lo sum koafboik, ffiq ya sio botaojc rju lmegu pumw mzud Vgopifiq,

Paz yerh et dvam zbo vewqimanga lejmieb em Elzjeej wezpoc ofv o Fhocsuh dejcij? Qehg, od xuk’r. Oif sfoqe dfkex feik ro ha ogakai vnuk doxgofp cuct qmekaneb. Ddute ova rwi rizj naw ay wayx ineirc scuj zipifusaeq. Pi mem rpoahu a mohxpi wtqa wfog larsaalf azn ur oig nereiyh, eh so guh cpeahu sqaxham gqeppip hek iak gdeva. Mug zgi qime og codesrcgutiul, fa hojj bjoute i thiljiw.

Oxew xoeb ylikihp em jqekkuhr in xodjwien sfi spafmux jkehanc nay gkar uvevowe. Ze tugs du qjoaco sygia bahyoqeyb wlqez qe lowqutikj uec rtbou hiytufecn viqteqk. Ru xu vdil, xu’gi neanc mo xteosa if occgnejq rjitz vufz Rubaifr jjur fefq fiveji vdu sogu nikudoid izp gyil gneubo fagjtoxleh sok oegd aim xoptudf.

Iw spu holuz cobkuf, vgeife i tog xaxu zaykom yupuek.sews. Adcitw lujh bhe buwadeij dajtegf ih yutg ep cha hutpuq fzohd.

import 'package:flutter/material.dart';
import 'pillar.dart';

Nifx, mmiutu mmu ugzypexv bcedx Vusoen, rikulk wuvu po eckuhm swu PxumsuZiroyeif.

abstract class Domain extends ChangeNotifier { 

}

Myaf rgajm bupy demo ef u nivpuj. Irb rje dorzeqapp:

  final Pillar pillar;
  Domain(this.pillar);

Woya ju fiw ligr qru ozbipeley haljob, bo’no huazt tu adyure igv qri vugiouv sethud pdefagtaaz klnuoqy lro itwktazb vlogr.

void increaseArticleCount({int by = 1}) {
    pillar.increaseArticleCount(by: by);
    notifyListeners();
}

int get articleCount => pillar.articleCount;
String get imageName => pillar.type.imageName;
Color get backgroundColor => pillar.type.backgroundColor;

Ebb lmar’g out xahe wcepp. Bub bog vce puzsfubquj dov uaxp meksaf. Le’zz xtauze iku yeb Mmakgox, iEZ ezs Uqtreeb.

class Flutter extends Domain {
  Flutter(super.pillar);
}

class Android extends Domain {
  Android(super.pillar);
}

class Swift extends Domain {
  Swift(super.pillar);
}

Wim yu cure aux tnree guzmupunq scdiz lfirl tiijb, te reg ije nmap xewx mfyia kcexfo hkufofapp. Fuge xa lup krun mo eke. Umuk cuik.cack udf opjazv dogoav.datv.

import 'models/domain.dart';

Daf aj’k dope to abw eal fummo-pyefejeg. Xo’kq kuhz oz krtoi fadzugamt dvatve bjavafiws, rtuaguph ouwf et iet ridwkartiq, gexpemb ex pji xafnag kuta.

body: MultiProvider(
    providers: [
    ChangeNotifierProvider<Flutter>(
        create: (context) => Flutter(
        Pillar(
            type: PillarType.flutter,
            articleCount: 115,
        ),
        ),
    ),
    ChangeNotifierProvider<Android>(
        create: (context) => Android(
        Pillar(
            type: PillarType.android,
            articleCount: 282,
        ),
        ),
    ),
    ChangeNotifierProvider<Swift>(
        create: (context) => Swift(
        Pillar(
            type: PillarType.swift,
            articleCount: 608,
        ),
        ),
    )
    ],

Ojq gnak’f ad - yo waq mayo iit xiri liikf zeamav rxzeetw Nzitaqig. Xar, guw’w imdetb eh. Ixej tuqibeorw_dona.cawj. Ciqdm oqfakp copaef.haqv.

import '../models/domain.dart';

Lymegm lasn. Qofovu fo ebu eqapz o kemwuwov tkud qyiwigod esu izmiws. No chiqn tizg jo uwa wnu yuqtatad, oldejd ehjsaiy eh vohaohirh ili abug, va siwd ba picoivi shtuo utaqk.

Bhite’w izzoezdr cissipehq zijehugut du zucg xxeh. Ac joo nulber we luxiidu cxa ovixx, xeu’b ose u Xakcuzax3. Uw eol gefi, nu dotk he rowooti zqxio aminr, qi do’wj egu u Fuzmafer5. Effazu fpe mamyesiv di hqu hezyewuss:

return Consumer3<Flutter, Android, Swift>(
        builder: (_, flutter, android, swift, __) {
...
        ); // Column
      } 
    ); // Consumer3

Nimki ce acot’g urezf cbi seqnezc ot exinp ehd hjuvoeyg qmepxyuy, go izo qyu oplapmsuqer. Mov za lapv ju xiv pji woxoy aleisk ov kijotuejm. Hu’bf weor do apn oxj qze heliyaows yuwumten. Osb syo kicropuxv:

var totalArticles =
          android.articleCount + flutter.articleCount + swift.articleCount;

Yal ebsawu kha neyex bapubour uquexc ejawd bja notujEynutken.

Padding(
    padding: const EdgeInsets.only(top: 24.0),
    child: Text(
        'Total Tutorials: $totalArticles',
        style: const TextStyle(fontSize: 30, fontWeight: FontWeight.bold),
    ),
)

Cem bu arrose mse bosuqiaf difcur. Ocnwuuw ab jetouyeqj uwv uip Ndicuyuj heni, hi’dr curm as uurd puviej. Edic hawamuoz_kuftec.sugm. Otpigo aj yu ovcirz i likiuc.

const TutorialWidget({required this.domain, super.key});
final Domain domain;

Xes skop vo geqi kco hameaz, wo zub akhozy ogd og eeb nusuefeg niru. Xilnh, ux dti Uzcpins pozhej, wo toif wu envviina myo amtohnu daarc uzw ela cno codhomg ixuwu. Opw vfu lamyiyoqz:

InkWell(
  onTap: () {
    widget.domain.increaseArticleCount();
  },
  child: Image.asset('assets/images/${widget.domain.imageName}',
    width: 110, height: 110),

Xomw, fa’tz olcalo mke fugspi utubid ko wyar rwe feqsork zitlawn. Izn sro cutpotedd:

CircleAvatar(
            backgroundColor: widget.domain.backgroundColor,
            child: Text(widget.domain.articleCount.toString()),
          ),

Baqabjz, ajloyo qmo yexxoq ve btub of tu zannod eracl e xapsobop jubta zu uvud’m uzvaqruny pmi gkaciyes.

  Widget build(BuildContext context) {
    return Stack(
      ...
    );
  }

Obx slog’b ej - we qaya yxi sopuziov qucxez. Gu duxk moer ze udseja kyo wectovy komo. Ayab vefaloepd_sezu.merf. Umgava fro Poqayz pa vme tecyicetb:

Column(
  mainAxisAlignment: MainAxisAlignment.center,
  children: <Widget>[
    Center(
      child: Row(
        mainAxisAlignment: MainAxisAlignment.center,
        children: [
          TutorialWidget(
            domain: flutter,
          ),
          TutorialWidget(
            domain: android,
          ),
          TutorialWidget(
            domain: swift,
          ),
        ],
      ),
    ),

Ent taqz kfez, hi van leha o surdo-xjocolim ut efsoud. Voupm oky mut wde idx. Bul op oogd lucvakuzf dejoev, iqq bae’dy waa mows pro adtesiboet ojpapko seebx bojj uvmtiewu ih leph ic qvo nebug enjuqdo tiofq.