'MVUUFS޲͚ͷύοέʔδ ࡞ͬͯQVCͰެ։ͨ͠࿩ !LVSPOFLPNJDIBFM Ͷ͜·͍͚Δ 

˓˓˓ͳϩδοΫ͕ඞཁͩɾɾɾ
˚˚˚ͳը໘෦඼͕͋ͬͨΒ͍͍ͷʹɾɾɾ
Ͱ΋ɺଞʹ΋ඞཁͱ͍ͯ͠Δਓ͕͍ͦ͏ͩͳʁʁʁ 

'MVUUFS %BSU ΤίγεςϜ
l1VCz
IUUQTQVCEBSUMBOHPSH 

1VC
cc
%BSUݴޠ༻ͷύοέʔδϚωʔδϟʔ
3VCZͰ͍͏ͱ͜ΖͷHFN
/PEFKTͰ͍͏ͱ͜ΖͷOQN 

७ਮͳ%BSUݴޠ༻ͷϥΠϒϥϦ΋ ͋Ε͹ɺ'MVUUFS༻ͷը໘෦඼ 8JEHFU ΋͋Γ·͢ 

ΦϨΦϨ8JEHFUΛ
શੈքʹެ։͢Δʢஏʣ 

ಈػ 

'MVUUFSඪ४෇ଐͷ8JEHFU
l4USFBN#VJMEFSz ʮ4USFBNʯͱ͍͏ϥΠϒϥϦΛ࢖ͬͯɺ
ඇಉظʹσʔλΛऔಘͯ͠ը໘Λ࡞Γ͍ͨ࣌ʹ࢖͑Δ8JEHFUɻ
·ͩσʔλ͕औಘͰ͖ͯͳ͍ͱ͖͸ʙ
σʔλऔಘ͕Τϥʔͷͱ͖͸ʙ
σʔλ͕औಘͰ͖ͨΒʙ
Έ͍ͨͳ෼ذΛ΋ͬͯը໘Λ࡞Δ͜ͱ͕Ͱ͖Δɻ
4USFBNͷঢ়ଶ͕มΘͬͨΒࣗಈͰ࠶ඳը΋ͯ͘͠ΕΔɻ 

'MVUUFSඪ४෇ଐͷ8JEHFU
l4USFBN#VJMEFSz ʮ4USFBNʯͱ͍͏ϥΠϒϥϦΛ࢖ͬͯɺ
ඇಉظʹσʔλΛऔಘͯ͠ը໘Λ࡞Γ͍ͨ࣌ʹ࢖͑Δ8JEHFUɻ
·ͩσʔλ͕औಘͰ͖ͯͳ͍ͱ͖͸ʙ
σʔλऔಘ͕Τϥʔͷͱ͖͸ʙ
σʔλ͕औಘͰ͖ͨΒʙ
Έ͍ͨͳ෼ذΛ΋ͬͯը໘Λ࡞Δ͜ͱ͕Ͱ͖Δɻ
4USFBNͷঢ়ଶ͕มΘͬͨΒࣗಈͰ࠶ඳը΋ͯ͘͠ΕΔɻ ίʔυ͕ϞϠοͱ͢Δʂ 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('ૉͷStreamBuilder'), ), body: StreamBuilder( stream: widget.stream, builder: (BuildContext context, AsyncSnapshot snapshot) { // ΋͠ΤϥʔͳΒΞΠίϯΛදࣔʢ௨৴Τϥʔ࣌ͳͲʣ if (snapshot.hasError) { return Icon(Icons.error_outline); } // σʔλ͕·ͩಧ͍͍ͯͳ͍ؒ͸ɺۭനΛදࣔʢॳճඳը࣌ͳͲʣ if (!snapshot.hasData) { return Container(); } // ʻຊ໋ʼσʔλ͕औΕͨΒը໘ʹදࣔ return Center( child: Text( snapshot.data, style: TextStyle(fontSize: 30.0), )); }, ), ); 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('ૉͷStreamBuilder'), ), body: StreamBuilder( stream: widget.stream, builder: (BuildContext context, AsyncSnapshot snapshot) { // ΋͠ΤϥʔͳΒΞΠίϯΛදࣔʢ௨৴Τϥʔ࣌ͳͲʣ if (snapshot.hasError) { return Icon(Icons.error_outline); } // σʔλ͕·ͩಧ͍͍ͯͳ͍ؒ͸ɺۭനΛදࣔʢॳճඳը࣌ͳͲʣ if (!snapshot.hasData) { return Container(); } // ʻຊ໋ʼσʔλ͕औΕͨΒը໘ʹදࣔ return Center( child: Text( snapshot.data, style: TextStyle(fontSize: 30.0), )); }, ), ); ඳըʹඞཁͳσʔλ 4USJOH ͸ɺ
TOBQTIPUEBUBͷதʹೖ͍ͬͯΔ TOBQTIPUIBT&SSPSΛΈͯɺ
Τϥʔ͕ൃੜͨ͠ͱ͖͸ԿΛඳը͢Δ͔෼ذ͢Δ TOBQTIPUIBT%BUBΛΈͯɺ
σʔλ͕·ۭͩͷͱ͖͸ԿΛඳը͢Δ͔෼ذ͢Δ ˡ࣮͸͕͜͜ϝΠϯͰ࣮૷͠ͳ͚Ε͹͍͚ͳ͍෦෼ ˞ࡾ߲ԋࢉࢠͰॻ͍ͯΔέʔε΋Α͘Έ·͢ʢݸਓతʹ͸ಡΈͮΒ͍ʣ 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('ૉͷStreamBuilder'), ), body: StreamBuilder( stream: widget.stream, builder: (BuildContext context, AsyncSnapshot snapshot) { // ΋͠ΤϥʔͳΒΞΠίϯΛදࣔʢ௨৴Τϥʔ࣌ͳͲʣ if (snapshot.hasError) { return Icon(Icons.error_outline); } // σʔλ͕·ͩಧ͍͍ͯͳ͍ؒ͸ɺۭനΛදࣔʢॳճඳը࣌ͳͲʣ if (!snapshot.hasData) { return Container(); } // ʻຊ໋ʼσʔλ͕औΕͨΒը໘ʹදࣔ return Center( child: Text( snapshot.data, style: TextStyle(fontSize: 30.0), )); }, ), ); *G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
*G
TOBQTIPUIBT%BUB
Զ͸൑ఆࣜʹόάΛ࡞ΓࠐΉʂ
ઈରʹͩʂ 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('ૉͷStreamBuilder'), ), body: StreamBuilder( stream: widget.stream, builder: (BuildContext context, AsyncSnapshot snapshot) { // ΋͠ΤϥʔͳΒΞΠίϯΛදࣔʢ௨৴Τϥʔ࣌ͳͲʣ if (snapshot.hasError) { return Icon(Icons.error_outline); } // σʔλ͕·ͩಧ͍͍ͯͳ͍ؒ͸ɺۭനΛදࣔʢॳճඳը࣌ͳͲʣ if (!snapshot.hasData) { return Container(); } // ʻຊ໋ʼσʔλ͕औΕͨΒը໘ʹදࣔ return Center( child: Text( snapshot.data, style: TextStyle(fontSize: 30.0), )); }, ), ); Զ͸൑ఆࣜʹόάΛ࡞ΓࠐΉʂ
ઈରʹͩʂ 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('ૉͷStreamBuilder'), ), body: StreamBuilder( stream: widget.stream, builder: (BuildContext context, AsyncSnapshot snapshot) { // ΋͠ΤϥʔͳΒΞΠίϯΛදࣔʢ௨৴Τϥʔ࣌ͳͲʣ if (snapshot.hasError) { return Icon(Icons.error_outline); } // σʔλ͕·ͩಧ͍͍ͯͳ͍ؒ͸ɺۭനΛදࣔʢॳճඳը࣌ͳͲʣ if (!snapshot.hasData) { return Container(); } // ʻຊ໋ʼσʔλ͕औΕͨΒը໘ʹදࣔ return Center( child: Text( snapshot.data, style: TextStyle(fontSize: 30.0), )); }, ), ); Τϥʔ࣌ʹද͍ࣔͨ͠8JEHFU ۭന࣌ʹද͍ࣔͨ͠8JEHFU ਖ਼ৗ࣌ʹද͍ࣔͨ͠8JEHFU ͦΕͧΕࢦఆͨ͠Βྑ͘Ͷʁ 

4BGFUZ4USFBN#VJMEFS lόάΔࢲͰ΋ͪΐͬͱ҆৺Ͱ͖Δ4USFBN#VJMEFSz 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('SafetyStreamBuilder'), ), body: SafetyStreamBuilder( stream: widget.stream, blankWidget: Container(), errorWidget: Icon(Icons.error_outline), builder: (BuildContext context, String message) => Center( child: Text( message, style: TextStyle(fontSize: 30.0), ), ), ), ); 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('SafetyStreamBuilder'), ), body: SafetyStreamBuilder( stream: widget.stream, blankWidget: Container(), errorWidget: Icon(Icons.error_outline), builder: (BuildContext context, String message) => Center( child: Text( message, style: TextStyle(fontSize: 30.0), ), ), ), ); ˡσʔλ͕·ͩແ͍࣌ʹඳը͍ͨ͠8JEHFU ˡΤϥʔ࣌ʹඳը͍ͨ͠8JEHFU ˢσʔλऔಘ׬ྃޙʹඳը͍ͨ͠8JEHFU 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('SafetyStreamBuilder'), ), body: SafetyStreamBuilder( stream: widget.stream, blankWidget: Container(), errorWidget: Icon(Icons.error_outline), builder: (BuildContext context, String message) => Center( child: Text( message, style: TextStyle(fontSize: 30.0), ), ), ), ); JGจ͕ফ͑ͨʂ
ਖ਼ৗܥʹूதͰ͖Δʂ
όάΛ࡞Γͨͯ͘΋࡞Εͳ͍ʂ 

@override Widget build(BuildContext context) => Scaffold( appBar: AppBar( title: Text('SafetyStreamBuilder'), ), body: SafetyStreamBuilder( stream: widget.stream, builder: (BuildContext context, String message) => Center( child: Text( message, style: TextStyle(fontSize: 30.0), ), ), ), ); CMBOL8JEHFUͱFSSPS8JEHFU͸
লུ͢Δ͜ͱ΋Մೳ
˞ॳظ஋͸ͦΕͧΕۭനͱ ʂ ϚʔΫ 

ΦϨΦϨύοέʔδͷ ࡞Γํ 

ίϚϯυҰൃͰϓϩδΣΫτ࡞੒
flutter create --template=package safety_stream_builder 

࠷௿ݶඞཁͳ΋ͷ͸ɺશͯࣗಈੜ੒͞ΕΔ 

ᶃίʔυΛॻ͘ᶄᶅॴ৴ද໌ ˡᶃίʔυ ˡᶄ࡞ऀ໊ͱ͔ ˡᶅʢॳճόʔδϣϯʹʣ
ͲΜͳػೳ͕͋Δͱ͔ 

library safety_stream_builder; import 'dart:async'; import 'package:flutter/material.dart'; typedef Widget AsyncWidgetSafetyBuilder(BuildContext context, T data); typedef Widget BuildHandler(BuildContext context); class SafetyStreamBuilder extends StreamBuilder { static BuildHandler _buildErrorWidget = _defaultBuildErrorWidget; static BuildHandler _buildBlankWidget = _defaultBuildBlankWidget; final AsyncWidgetSafetyBuilder _builder; final Widget blankWidget; final Widget errorWidget; factory SafetyStreamBuilder({ @required AsyncWidgetSafetyBuilder builder, Key key, T initialData, Stream stream, Widget blankWidget, Widget errorWidget, }) => SafetyStreamBuilder._( builder: builder, unusedBuilder: (_, __) => null, // dummy key: key, initialData: initialData, stream: stream, blankWidget: blankWidget, errorWidget: errorWidget, ); SafetyStreamBuilder._({ @required AsyncWidgetSafetyBuilder builder, @required AsyncWidgetBuilder unusedBuilder, Key key, T initialData, Stream stream, this.blankWidget, this.errorWidget, }) : _builder = builder, super( key: key, initialData: initialData, stream: stream, builder: unusedBuilder, ); @override Widget build(BuildContext context, AsyncSnapshot snapshot) { if (snapshot.hasError) { return errorWidget != null ? errorWidget : _buildErrorWidget(context); } if (!snapshot.hasData) { return blankWidget != null ? blankWidget : _buildBlankWidget(context); } return _builder(context, snapshot.data); } static Widget _defaultBuildErrorWidget(BuildContext _) => const Icon(Icons.error_outline); static Widget _defaultBuildBlankWidget(BuildContext _) => Container(); static void handleError({@required BuildHandler build}) => _buildErrorWidget = build; static void handleBlank({@required BuildHandler build}) => _buildBlankWidget = build; } ᶃϑΝΠϧʹίʔυΛॻ͘ 

name: safety_stream_builder description: A new flutter package project. version: 0.0.1 author: kuronekomichael homepage: https://github.com/kuronekomichael/SafetyStreamBuilder environment: sdk: ">=2.0.0-dev.68.0 <3.0.0" dependencies: flutter: sdk: flutter dev_dependencies: flutter_test: sdk: flutter flutter: ᶄQVCTQFDZBNMʹɺ
BVUIPSͱIPNFQBHFΛॻ͘ 

## v0.0.1 * Initial Release * No API Document ᶅ$)"/(&-0(NEʹɺ
ϦϦʔεϊʔτΛॻ͘
ʢͳͯ͘΋ΠέΔ͚Ͳڐͤͳ͍ͷͰॻ͘ʣ 

ᶃTBGFZ@TUSFBN@CVJMEFSEBSUॻ͍ͨ
ᶄQVCTQFDZBNMʹ໊લॻ͍ͨ
ᶅ$)"/(&-0(NEʹϦϦʔεϊʔτॻ͍ͨ Αʔ͠
શੈքʹެ։ͪ͠Ό͏ͧʂ 

$ pub publish ↩ 

Pub needs your authorization to upload packages on your behalf. In a web browser, go to https:// accounts.google.com/o/oauth2/auth? access_type=offline&approval_prompt=force&re sponse_type=code&client_id=123456789- somethingsomethinganything.apps.googleuserco ntent.com&redirect_uri=http%3A%2F%2Flocalhos t%3A54569&scope=https%3A%2F%2Fwww.googleapis .com%2Fauth%2Fuserinfo.email Then click "Allow access". Waiting for your authorization... (PPHMFೝূ 

IUUQTQVCEBSUMBOHPSHQBDLBHFTTBGFUZ@TUSFBN@CVJMEFS 

IUUQTQVCEBSUMBOHPSHQBDLBHFTTBGFUZ@TUSFBN@CVJMEFS ଈެ։ʂʂʂ 

·ͱΊ w QVCެ։Χϯλϯա͗řşΔXXXXXX
w Ұ౓ެ։ͨ͠ύοέʔδ͸ɺݪଇͱͯ͠औΓԼ͛ෆՄ
 ʢউखʹऔΓԼ͛Δͱɺੈքதͷ୭͔ͷϓϩδΣΫτ͕ ಥવϏϧυΤϥʔʹͳΔ͔΋͠Εͳ͍ͷͰʣ
w ͍·QVC͸ϒϧʔΦʔγϟϯͳͷͰνϟϯε 

$ pub publish —dry-run ʲิ଍ʳ
lESZSVOzΛ͚ͭΔͱɺ
ެ։͢ΔલʹνΣοΫͰ͖·͢ 

શίʔυΛެ։ͯ͠·͢
IUUQTHJUIVCDPNLVSPOFLPNJDIBFM4BGFUZ4USFBN#VJMEFS