В настоящее время я разрабатываю приложение для еды и покупок. В этом приложении вы можете добавить то, что вы хотите съесть дальше, и получите вкладку «Покупки», где вы можете добавить свои товары, которые хотите купить дальше. Создано так, что Пользователь может пригласить другого Пользователя для совместного редактирования списка.
Я получаю ошибку, показанную ниже. Я не могу понять, как вернуть контейнер. В void saveInviteToFirestore пользователь не используется, мне нужно, чтобы он использовался?
Код
import 'package:flutter/material.dart';
import 'package:mealapp/models/Widgets/whenAndWhatToEat.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:intl/intl.dart';
import 'package:mealapp/models/global.dart';
import 'package:status_alert/status_alert.dart';
import 'package:firebase_auth/firebase_auth.dart';
class MealTile extends StatefulWidget {
final MealsAndWhen mealsAndWhen;
MealTile({this.mealsAndWhen});
@override
MealTileState createState() {
return MealTileState();
}
}
class MealTileState extends State<MealTile> {
String id;
final db = Firestore.instance;
String mail;
List<String> authors = [];
DateTime selectedDate = DateTime.now();
Future pickDate() async {
DateTime datepick = await showDatePicker(
context: context,
initialDate: new DateTime.now(),
firstDate: new DateTime.now().add(Duration(days: -0)),
lastDate: new DateTime.now().add(Duration(days: 365)));
if (datepick != null)
setState(() {
selectedDate = datepick;
});
}
Future<String> inputData() async {
final FirebaseUser user = await FirebaseAuth.instance.currentUser();
return user != null ? user.uid : null;
}
Future<String> inputDataMail() async {
final FirebaseUser user = await FirebaseAuth.instance.currentUser();
return user != null ? user.email : null;
}
String userId;
void _getUserId() {
inputData().then((value) => setState(() {
userId = value;
}));
}
String currentMail;
void _getMail(doc) {
inputDataMail().then((value) => setState(() {
currentMail = value;
}));
}
/*void _getAuthors(DocumentSnapshot doc) async {
authors = [];
//if (await FirebaseAuth.instance.currentUser() != null) {
authors = List.from(doc.data['Authors']);
print(doc.data['authors']);
//authors.insert(0, currentMail);
//}
}*/
Widget buildItem(DocumentSnapshot doc) {
DateTime now = doc.data['Date'].toDate();
DateFormat formatter = DateFormat('dd-MM-yyyy');
String formatted = formatter.format(now);
_getUserId();
_getMail(doc);
if (doc.data['Authors'] != null) {
//_getAuthors(doc);
//print('Current mail: ' + currentMail + authors.toString() + doc.data['Author'] + doc.data['Meal']);
}
if (now.day == DateTime.now().day) { // If the Date of the meal is today
deleteData(doc, false); // Delete it!
}
// You could also change ".day" to ".hour".
// Example: if (now.day == DateTime.now().day && now.hour == DateTime.hour())
// So, if a meal is set for 2PM, it will delete at 2PM
return FutureBuilder<FirebaseUser>(
future: FirebaseAuth.instance.currentUser(),
builder: (BuildContext context, AsyncSnapshot<FirebaseUser> snapshot) {
if (snapshot.hasData && snapshot != null) {
return Container(
margin: const EdgeInsets.all(8.0),
child: currentMail == doc.data['Author'] || // If the current mail is the author
List.from(doc.data['Authors']).contains(currentMail) // Or if the current mail is part of the authors
? Column( // then if true, show a Column
crossAxisAlignment: CrossAxisAlignment.center,
children: <Widget>[
Text(
'Meal:',
style: TextStyle(
fontSize: 24,
fontWeight: FontWeight.bold,
color: Colors.white),
textAlign: TextAlign.center,
),
Text(
'${doc.data['Meal']}',
style: TextStyle(
fontSize: 24,
fontWeight: FontWeight.bold,
color: Colors.white),
textAlign: TextAlign.center,
),
SizedBox(height: 20),
Text(
'When:',
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.bold,
color: Colors.white),
textAlign: TextAlign.center,
),
Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
IconButton(
onPressed: () => updateData(doc),
color: lightBlueColor,
icon: Icon(Icons.calendar_today,
color: Colors.white),
tooltip: 'Update Date',
),
Text(
formatted,
style: TextStyle(
fontSize: 20,
fontWeight: FontWeight.bold,
color: Colors.white),
textAlign: TextAlign.center,
),
],
),
Row(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
SizedBox(width: 8),
FlatButton(
color: Colors.red,
onPressed: () => deleteData(doc, true),
shape: RoundedRectangleBorder(
borderRadius:
BorderRadiusDirectional.circular(12)),
child: Row(children: <Widget>[
Text('Delete',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.white)),
Icon(Icons.delete_forever, color: Colors.white),
]),
),
SizedBox(width: 8),
FlatButton(
color: Colors.blue,
onPressed: () => [
showDialog(
context: context,
builder: (BuildContext context) {
return Dialog(
child: invite(doc),
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(
Radius.circular(12)),
),
);
})
],
shape: RoundedRectangleBorder(
borderRadius:
BorderRadiusDirectional.circular(12)),
child: Row(children: <Widget>[
Text('Invite',
style: TextStyle(
fontWeight: FontWeight.bold,
color: Colors.white)),
Icon(Icons.share, color: Colors.white),
]),
),
],
),
],
)
: Text(''), // if false, show an empty text widget
decoration: BoxDecoration(
color: lightBlueColor,
borderRadius: BorderRadius.all(Radius.circular(12)),
),
);
}
/*Navigator.pop(context);
return HomePage();*/
});
}
@override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: darkGreyColor,
body: ListView(
padding: EdgeInsets.only(top: 220),
children: <Widget>[
StreamBuilder<QuerySnapshot>(
stream: db
.collection('mealList')
.orderBy('Date', descending: false) // Order by Date, not descending
.snapshots(),
builder: (context, snapshot) {
if (snapshot.hasData) {
return Column(
children: snapshot.data.documents
.map((doc) => buildItem(doc))
.toList());
} else {
return Container();
}
},
),
],
),
);
}
/*share(BuildContext context, DocumentSnapshot doc) {
final RenderBox box = context.findRenderObject();
final dynamic date = timeago.format(doc['Date'].toDate());
Share.share(
"${doc['Meal']} - $date",
subject: doc['Meal'],
sharePositionOrigin: box.localToGlobal(Offset.zero) & box.size,
);
}*/
Widget invite(DocumentSnapshot doc) {
final _formKey = GlobalKey<FormState>();
return Form(
key: _formKey,
child: Padding(
padding: const EdgeInsets.all(24.0),
child: Column(mainAxisSize: MainAxisSize.min, children: <Widget>[
Center(
child: Text(
"Invite someone by mail",
style: TextStyle(fontWeight: FontWeight.bold, fontSize: 16),
)),
SizedBox(
height: 24,
),
TextFormField(
decoration: InputDecoration(
border: OutlineInputBorder(
borderRadius: BorderRadius.all(Radius.circular(12))),
labelText: 'Enter the email address'),
validator: (value) {
if (value.isEmpty) {
return 'Please enter an email address';
}
return null;
},
onSaved: (value) => mail = value,
),
FlatButton(
onPressed: () async {
if (_formKey.currentState.validate()) {
_formKey.currentState.save();
saveInviteToFirestore(doc, mail);
}
},
shape: RoundedRectangleBorder(
borderRadius: BorderRadius.all(Radius.circular(12))),
child: Text("Save"),
color: redColor,
textColor: Colors.white,
),
]),
),
);
}
Future<String> getCurrentUser() async {
return await FirebaseAuth.instance.currentUser().then((value) => value.uid);
}
void saveInviteToFirestore(DocumentSnapshot doc, String email) async {
final String user = await getCurrentUser();
var list = List<String>();
list.add(email);
Firestore.instance
.collection('mealList')
.document(doc.documentID)
.updateData({"Authors": FieldValue.arrayUnion(list)});
//setState(() => id = doc.documentID);
StatusAlert.show(
context,
duration: Duration(seconds: 2),
title: 'Added',
subtitle: 'You have Added your and the Date to your List',
configuration: IconConfiguration(icon: Icons.done),
);
//Navigator.pop(context);
}
void deleteData(DocumentSnapshot doc, bool showMessage) async {
await db.collection('mealList').document(doc.documentID).delete();
setState(() => id = null);
if (showMessage) {
StatusAlert.show(
context,
duration: Duration(seconds: 2),
title: 'Deleted',
subtitle: 'You have Deleted your Meal',
configuration: IconConfiguration(icon: Icons.delete),
);
}
}
void updateData(DocumentSnapshot doc) async {
await pickDate();
await db
.collection('mealList')
.document(doc.documentID)
.updateData({'Date': selectedDate});
StatusAlert.show(
context,
duration: Duration(seconds: 2),
title: 'Updated',
subtitle: 'You have updated your Meal Date',
configuration: IconConfiguration(icon: Icons.done),
);
}
}
Ошибка
The following assertion was thrown building FutureBuilder<FirebaseUser>(dirty, state: _FutureBuilderState<FirebaseUser>#a4504):
A build function returned null.
The offending widget is: FutureBuilder<FirebaseUser>
Build functions must never return null.
To return an empty space that causes the building widget to fill available room, return "Container()". To return an empty space that takes as little room as possible, return "Container(width: 0.0, height: 0.0)".
The relevant error-causing widget was
FutureBuilder<FirebaseUser>
lib/…/MealPlan/mealTile.dart:92
When the exception was thrown, this was the stack
#0 debugWidgetBuilderValue.<anonymous closure>
package:flutter/…/widgets/debug.dart:276