How to read data from Flutter elements - dart

I've the below code for entering some data, I do not know how to handle it!
i.e. What shall I write at the onPressed for the IconButton so that the data is read from all the elements (name, birthday, ...)? and how to display it in Dialog to check if read correctly?
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return new MaterialApp(
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.deepOrange,
),
home: new MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
var _value=false;
double _bodyHeight=0.0;
void onchange(bool value) {
setState(() {
_value = value;
this._bodyHeight = (value == true) ? 400.0 : 0.0;
});
}
#override
Widget build(BuildContext context) {
return new Scaffold(
backgroundColor: Colors.grey[500],
appBar: new AppBar(
title: new Text(widget.title),
),
body: new SingleChildScrollView(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new Card(
child: new Container(
height: 50.0,
child: new Row(
mainAxisAlignment: MainAxisAlignment.end,
children: <Widget>[
new Text("Select me pls"),
new Switch(value: _value, onChanged: (bool value) => onchange(value)),
],
),
),
),
new Card(
child: new AnimatedContainer(
child: new ListView(
children: <Widget>[
new ListTile(
leading: const Icon(Icons.person),
title: new TextField(
decoration: new InputDecoration(
hintText: "Name",
),
),
),
new ListTile(
leading: const Icon(Icons.phone),
title: new TextField(
decoration: new InputDecoration(
hintText: "Phone",
),
),
),
new ListTile(
leading: const Icon(Icons.email),
title: new TextField(
decoration: new InputDecoration(
hintText: "Email",
),
),
),
const Divider(
height: 1.0,
),
new ListTile(
leading: const Icon(Icons.label),
title: const Text('Nick'),
subtitle: const Text('None'),
),
new ListTile(
leading: const Icon(Icons.today),
title: const Text('Birthday'),
subtitle: const Text('February 20, 1980'),
),
new IconButton(icon: const Icon(Icons.save),
onPressed: null
/*
*
* What shall I write here to read the data in the elements
*
*
*
* */
),
],
),
curve: Curves.easeInOut,
duration: const Duration(milliseconds: 500),
height: _bodyHeight,
// color: Colors.red,
),
),
],
),
),
);
}
}

One way is that TextFields take a property called TextEditingController which allow you to access the value of the TextField.
And to show a dialog you can just call showDialog() function.
class TextFieldExample extends StatefulWidget {
#override
_TextFieldExampleState createState() => new _TextFieldExampleState();
}
class _TextFieldExampleState extends State<TextFieldExample> {
TextEditingController c1;
TextEditingController c2;
#override
void initState() {
c1 = new TextEditingController();
c2 = new TextEditingController();
super.initState();
}
#override
Widget build(BuildContext context) {
return new Scaffold(
body: new Center(
child: new Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
new TextField (
controller: c1,
),
new TextField(
controller: c2,
),
new OutlineButton(onPressed: () {
showDialog(child: new AlertDialog(
content: new Text("You entered ${c1.text} ${c2.text} ")
),
context: context
);
},
child: new Text("Show Dialog"),
)
],
),
),
);
}
}

Related

Custom slider with emojis

I am building a flutter app and want to create a custom slider with emojis very similar to the reflectly app. I am attaching a screenshot , as you change the slider the emoji changes. I am pretty new to flutter and am struggling with the slider widget
You could do something like that:
I didn't use images for emojis faces but could put you in the right direction.
Full code:
import 'package:flutter/material.dart';
const _emojis = ['😃','😜','🤓','😁','😂','😞'];
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
// This widget is the root of your application.
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
double _value = 0;
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Container(
decoration: BoxDecoration(
gradient: new LinearGradient(
colors: [Colors.teal, Colors.tealAccent],
begin: Alignment.bottomLeft,
end: Alignment.topRight
)
),
child: Center(
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(
'${_emojis[_value.toInt()]}',
style: Theme.of(context).textTheme.display1,
),
Padding(
padding: const EdgeInsets.symmetric(horizontal: 8.0),
child: Container(
child: Row(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text(_emojis[0], softWrap: true),
Expanded(
child: Slider(
value: _value,
//label: _emojis[_value.toInt()],
min: 0.0,
max: 5.0,
divisions: 5,
onChangeStart: (double value) {
print('Start value is ' + value.toString());
},
onChangeEnd: (double value) {
print('Finish value is ' + value.toString());
},
onChanged: (double value) {
setState(() {
_value = value;
});
},
activeColor: Colors.white,
inactiveColor: Colors.black45,
),
),
Text(_emojis[5], softWrap: true,)
],
),
),
),
],
),
),
),
);
}
}
This reviewpage animation is close to 90% of the reflectly animation.

Flutter FlatButton does not show tap animation / ripple effect

I have the following code:
return new ListTile(
leading: new CircleAvatar(
backgroundColor: Colors.blue,
child: new Image.network(
"http://res.cloudinary.com/kennyy/image/upload/v1531317427/avatar_z1rc6f.png")),
title: new Row(
children: <Widget>[
new Expanded(child: new Text(message)),
new FlatButton(onPressed: null, child: new Text("Delete"))
]
),
subtitle: new Text(from),
);
which created a tile in my ListView.
Each tile should have a button.
When I tap the button - I don't see any ripple effect or animation that I actually clicked. I was pretty sure it's a part of the Material theme as a gesture for FlatButtons, but I tried a solution I found, using InkWell:
return new ListTile(
leading: new CircleAvatar(
backgroundColor: Colors.blue,
child: new Image.network(
"http://res.cloudinary.com/kennyy/image/upload/v1531317427/avatar_z1rc6f.png")),
title: new Row(
children: <Widget>[
new Expanded(child: new Text(message)),
InkWell(
child: FlatButton(onPressed: null, child: new Text("Delete"), color: Colors.amber))
]
),
subtitle: new Text(from),
);
But still - my listview button does not have any ripple effect when tapped.
Any idea?
Flutter buttons are disabled by default. To enable a button, set its onPressed or onLongPress properties to a non-null value.
The ripple is not visible because you've set the property of your onPressed to null.
new FlatButton(onPressed: null, child: new Text("Delete"))
Change the onPressed property to something like this:
new FlatButton(onPressed: (){}, child: new Text("Delete"))
To compare here is an example of a no-null onPressed and a null valued onPressed.
import 'package:flutter/material.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({Key? key}) : super(key: key);
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const MyHomePage(title: 'Flutter Demo Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
final String title;
#override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
#override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: ListTile(
leading: new CircleAvatar(
backgroundColor: Colors.blue,
child: new Image.network(
"http://res.cloudinary.com/kennyy/image/upload/v1531317427/avatar_z1rc6f.png")),
title: new Row(children: <Widget>[
//new Expanded(child: new Text(message)),
new TextButton(
onPressed: () {},
child: new Text("Delete"),
),
new TextButton(
onPressed: null,
child: new Text("Delete"),
)
]),
//subtitle: new Text(from),
),
);
}
}
*Note that the FlatButton is now deprecated so I've used TextButton in the example.

Flutter : unable to reuse views in appdrawer

File:homepage.dart
class _HomePageState extends State<HomePage> {
var _scaffoldBody;
var _scaffoldTitle;
#override
initState() {
_scaffoldTitle=new Text("Wall");
_scaffoldBody=new Center(child:CircularProgressIndicator());
}
#override
Widget build(BuildContext context) {
return Scaffold(
drawer: new Drawer(
child: ListView(
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child: Text('Drawer Header'),
decoration: BoxDecoration(
color:Theme.of(context).accentColor,
),
),
ListTile(
title: Text('Home'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("Home");
_scaffoldBody=new Text("Home Page");
});
Navigator.pop(context);
},
),
ListTile(
title: Text('MenuItem1'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("1st Menu");
_scaffoldBody=new TestPage("Page 1");
});
Navigator.pop(context);
},
),
ListTile(
title: Text('MenuItem2'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("2nd Item");
_scaffoldBody=new TestPage("Page 2");
});
Navigator.pop(context);
},
),
],
),
),
appBar: new AppBar(
title: _scaffoldTitle,
elevation: 2.0,
actions: <Widget>[
],
),
body:_scaffoldBody,
);
}
file: TestPage.dart
import 'package:flutter/material.dart';
class TestPage extends StatefulWidget{
final String rollNumber;
TestPage(this.rollNumber);
#override
TestPageState createState() => new TestPageState(rollNumber);
}
class TestPageState extends State<TestPage>{
String rollNumber;
TestPageState(this.rollNumber);
#override
Widget build(BuildContext context) {
return new Text(rollNumber);
}
}
Output:
When I chose : "Home" from drawer it shows "Home Page"
Then I chose : "MenuItem1" it showed "Page 1"
Then I chose : "MenuItem2" it showed same "Page 1" (unexpected)
Then I chose : "Home" it showed "Home Page"
Then I chose : "MenuItem2" it showed correctly as "Page 2"
Then I chose : "MenuItem1" it showed "Page 2" (unexpected)
unable to solve this.Stuck!! Any solutions are appreciated. Thanks in advance!!
Update your TestPart.dart as follow:
import 'package:flutter/material.dart';
class TestPage extends StatefulWidget{
final String rollNumber;
TestPage(this.rollNumber);
#override
TestPageState createState() => new TestPageState();
}
class TestPageState extends State<TestPage>{
#override
Widget build(BuildContext context) {
return new Text(widget.rollNumber);
}
}
My StudentPage Class
import 'package:flutter/material.dart';
import 'package:firebase_database/firebase_database.dart';
import 'calendar_utils.dart';
import 'dart:async';
final mainReference = FirebaseDatabase.instance.reference();
class StudentPage extends StatefulWidget{
final String rollNumber;
StudentPage(this.rollNumber);
#override
StudentPageState createState() => new StudentPageState(rollNumber);
}
class StudentPageState extends State<StudentPage>{
final String currentRoll,currentYear="2018-19";
StudentPageState(this.currentRoll);
List<String> academicMonth=["June","July","August","September","October","November","December",
"January","February","March","April","May"];
int firstHalfYear=2018,secondHalfYear=2019;
List<Widget> _monthListArray=[new ListTile(title:new Text("Academic Year",style: new TextStyle(fontWeight: FontWeight.bold,fontSize: 20.0),),)];
List<Widget> _listView;
int _no_of_working=0;
int _no_of_present=0;
#override
void initState() {
// TODO: implement initState
_listView=[new Center(
child: new CircularProgressIndicator(),
)];
_loadMonths();
}
#override
Widget build(BuildContext context) {
return new RefreshIndicator(child: new ListView(
children: _listView,
), onRefresh: _loadMonths);
}
Future<Null> _loadMonths() async {
_listView.clear();
await mainReference.child("XXXX").child("attendance").child(
widget.rollNumber).child(currentYear).once().then((
DataSnapshot dataSnapshot) {
try {
int monthIndex=5; //monthIndex starts from June
for(var month in academicMonth){
debugPrint("Month:"+month);
monthIndex=(monthIndex+1)%12; //month index cycles throughout 1-12
if(monthIndex==0) monthIndex=12;
List<Widget> _daysList=[];
_monthListArray.add(new Padding(padding: EdgeInsets.all(16.0),child: new Text(month+" "+(monthIndex<6?secondHalfYear:firstHalfYear).toString(),style: new TextStyle(color: Colors.black87,fontWeight: FontWeight.bold,fontSize: 20.0),),)); //initializing the month
_monthListArray.add(new Padding(padding: EdgeInsets.only(top: 10.0,bottom: 10.0),child:
new Row(children: <Widget>[
new Expanded(
child: new Center(child: new Text("S",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("M",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("T",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("W",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("T",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("F",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
new Expanded(
child: new Center(child: new Text("S",style: new TextStyle(fontWeight: FontWeight.bold),),),
),
],),));
debugPrint(monthIndex.toString());
int freeSpace=CalendarUtils(1,monthIndex,monthIndex<6?secondHalfYear:firstHalfYear).getDayFromDate();
debugPrint("FreeSpace---"+freeSpace.toString());
if(freeSpace!=0){
for (var i = 0; i < freeSpace; i++) {
_daysList.add(new Text(""));
}
}
debugPrint(monthIndex.toString());
var year=monthIndex<6?secondHalfYear:firstHalfYear;
debugPrint("Year"+year.toString());
debugPrint("Forloop limit:"+CalendarUtils(1,monthIndex,monthIndex<6?firstHalfYear:secondHalfYear).numberOfDays().toString());
for(var day=1;day<=CalendarUtils(1,monthIndex,monthIndex<6?secondHalfYear:firstHalfYear).numberOfDays();day++){
try {
//debugPrint(day.toString()+":"+dataSnapshot.value[month][day].toString());
if (CalendarUtils(day, monthIndex,
monthIndex < 6 ? secondHalfYear: firstHalfYear)
.getDayFromDate() != 0){
if (dataSnapshot.value[month][day].toString() == "1") {
_no_of_working++;
_no_of_present++;
_daysList.add(
new Padding(padding: EdgeInsets.only(left: 10.0,right: 10.0,top: 2.0,bottom: 2.0),
child: new Container(
alignment: Alignment.center,
width: 30.0,
height: 30.0,
decoration: new BoxDecoration(
borderRadius: new BorderRadius.all(new Radius.circular(50.0)),
color: Colors.green),
child: new Text(
day.toString(),
style: new TextStyle(color: Colors.white),
),
),
)
);
}
else if (dataSnapshot.value[month][day].toString() == "0"){
_no_of_working++;
_daysList.add(
new Padding(padding: EdgeInsets.only(left: 10.0,right: 10.0,top: 2.0,bottom: 2.0),
child: new Container(
alignment: Alignment.center,
width: 30.0,
height: 30.0,
decoration: new BoxDecoration(
borderRadius: new BorderRadius.all(new Radius.circular(50.0)),
color: Colors.redAccent),
child: new Text(
day.toString(),
style: new TextStyle(color: Colors.white),
),
),
)
);
}
else {
_daysList.add(
new Padding(padding: EdgeInsets.only(left: 10.0,right: 10.0,top: 2.0,bottom: 2.0),
child: new Container(
alignment: Alignment.center,
width: 30.0,
height: 30.0,
decoration: new BoxDecoration(
borderRadius: new BorderRadius.all(new Radius.circular(50.0)),
),
child: new Text(
day.toString(),
style: new TextStyle(color: Colors.black),
),
),
)
);
}
}else {
_daysList.add(
new Center(child: new Text(day.toString(), style:
new TextStyle(color: Colors.black45),)));
}
}catch (e){
_daysList.add(new Center(child:new Text(day.toString(),style:
new TextStyle(color: Colors.black),) ));
}
}
Widget _daysGrid=new GridView.count(crossAxisCount: 7,
shrinkWrap: true,
physics: NeverScrollableScrollPhysics(),
childAspectRatio: 1.5,
children: _daysList,
);
_monthListArray.add(_daysGrid);
}
}catch(e){}
_monthListArray.add(new Text((_no_of_present/_no_of_working).toString()));
});
this.setState((){
_listView=_monthListArray;
});
}
}
My HomePage.dart
import 'package:flutter/material.dart';
import 'package:smart_school_parent/TestPage.dart';
import 'package:smart_school_parent/attendance.dart';
import 'package:smart_school_parent/post.dart';
import 'package:firebase_database/firebase_database.dart';
import 'package:smart_school_parent/auth.dart';
import 'dart:async';
class HomePage extends StatefulWidget {
final BaseAuth auth;
final VoidCallback onSignOut;
HomePage({Key key, this.auth, this.onSignOut}) : super(key: key);
#override
_HomePageState createState() => new _HomePageState(this.auth);
}
class _HomePageState extends State<HomePage> {
final mainReference = FirebaseDatabase.instance.reference();
List<PostData> post_list = new List();
var _scaffoldBody;
var _loading;
var _currentYear;
var _scaffoldTitle;
List<Widget> _childrenList=[new Text("Profiles",textAlign: TextAlign.left,style: new TextStyle(fontWeight: FontWeight.bold),)];
BaseAuth auth;
_HomePageState(this.auth);
#override
initState() {
//_children=updateChildren();
_updateChildren();
getList();
_loading=true ;
_scaffoldTitle=new Text("Wall");
_scaffoldBody=new Center(child:CircularProgressIndicator());
}
#override
Widget build(BuildContext context) {
return Scaffold(
drawer: new Drawer(
child: ListView(
// Important: Remove any padding from the ListView.
padding: EdgeInsets.zero,
children: <Widget>[
DrawerHeader(
child: Text('XXXXx'),
decoration: BoxDecoration(
color:Theme.of(context).accentColor,
),
),
ListTile(
title: Text('Wall'),
onTap: () {
setState(() {
_scaffoldTitle=new Text("Wall");
_scaffoldBody=new RefreshIndicator(child: _loadWall(), onRefresh: getList);
});
Navigator.pop(context);
},
),
Column(
children: _childrenList,
),
],
),
),
appBar: new AppBar(
title: _scaffoldTitle,
elevation: 2.0,
actions: <Widget>[
],
),
body:_scaffoldBody,
);
}
Future <Null> getList() async {
await mainReference.child("NISE-Coimbatore").child("posts").once().then((DataSnapshot dataSnapshot) {
this.setState(() {
post_list.clear();
if(dataSnapshot.value!=null){
for (var value in dataSnapshot.value.values) {
post_list.add(new PostData.fromJson(value));
//debugPrint(value.toString());
}
}else{
this.setState((){
});
}
});
});
setState(() {
_scaffoldBody=new RefreshIndicator(child: _loadWall(), onRefresh: getList);
});
}
Widget _loadWall(){
return Stack(
children: <Widget>[
new ListView.builder(itemBuilder: (BuildContext context,int index){
return new Post(post_list[index].image,post_list[index].title,post_list[index].content);
},
itemCount: post_list == null ? 0 : post_list.length,)
],
);
}
_updateChildren() async {
_currentYear= await mainReference.child("attendance").child("currentYear").once();
await auth.currentUser().then((String userId) async{
mainReference.child("NISE-Coimbatore").child("parents").child(userId).child('children').once().then((DataSnapshot dataSnapshot){
for (var value in dataSnapshot.value){
this.setState((){
_childrenList.add(
new Padding(
padding: EdgeInsets.only(left: 25.0),
child: ListTile(
title: Text(value.toString()),
onTap: () {
super.setState(() {
_scaffoldTitle=new Text(value.toString());
this._scaffoldBody=new StudentPage(value.toString());
});
Navigator.pop(context);
},
),
),
);
});
//debugPrint("Childrrncount::"+value.toString());
}
});
});
}
}
class PostData{
String title;
String content;
String image;
PostData(this.title, this.content, this.image);
PostData.fromJson(var value) {
this.title = value['title'];
this.content = value['content'];
this.image = value['image'];
}
}
_childrenList has two elements. The datasnapshot.values has [15505,15501] two roll numbers
Both rollnumbers from firebase appear on the drawer box and on tap it is expected to show StudentPage(15501.tostring()) or StudentPage(15505.tostring())
it works as expected if select "Wall" from drawer and then any of the "rollNumbers"
it is not working if i switch from one of the rollNumbers to other rollNumber in the drawer.
Similar to my first post. Only the _scaffoldTitle changes accordingly.

How to customize the SliverAppBar widget in flutter?

I would like to add some more information in the green area, but when user scrolls up, I keep the _ SliverAppBar on the top..., like this:
Here is my current source code:
body: new CustomScrollView(slivers: <Widget>[
const SliverAppBar(
pinned: true,
expandedHeight: 300.0, // TODO: check out later
flexibleSpace: const FlexibleSpaceBar(
title: const Text('_SliverAppBar')
),
),
new SliverList(delegate: new SliverChildListDelegate(_galleryListItems()))
]),
The FlexibleSpaceBar has a background property the accepts any Widget
Use to build the information you need:
FlexibleSpaceBar(
title: Text('_SliverAppBar'),
background: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('Info'),
],
),
),
Here is a more complete example that adds a subtitle and hides it when the user scrolls.
import 'package:flutter/material.dart';
void main() => runApp(new MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return new MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: new ThemeData(
primarySwatch: Colors.blue,
),
home: new MyHomePage(title: 'My Flutter Pad'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key key, this.title}) : super(key: key);
final String title;
#override
_MyHomePageState createState() => new _MyHomePageState();
}
const kExpandedHeight = 300.0;
class _MyHomePageState extends State<MyHomePage> {
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
return Scaffold(
body: NestedScrollView(
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
leading: Icon(Icons.menu),
actions: <Widget>[
new IconButton(
icon: new Icon(Icons.search),
highlightColor: Colors.white,
onPressed: () {},
),
],
expandedHeight: 200.0,
floating: false,
pinned: true,
flexibleSpace: FlexibleSpaceBar(
centerTitle: true,
background: Container(
decoration: BoxDecoration(
image: DecorationImage(
image: AssetImage("assets/images/bar.jpg"),
fit: BoxFit.cover)),
child: Column(
children: [
Expanded(
child: Align(
alignment: Alignment.bottomCenter,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
Text('NEW GAME'),
Text('Sekiro: Shadows Dies Twice'),
RaisedButton(
onPressed: () {},
child: Text('Play'),
),
],
),
),
),
],
),
)),
),
];
},
body: Center(
child: Text("Sample Text"),
),
),
);
}
}

Destruct and Construct cards in Flutter dynamically

I'm new to Flutter,
I want to destruct cards created initially and construct them again as per data provided in API call.
Basically when I tap on button in UI, it should call APIs and based on data from API call, if it is different from the data I already have, I want to destruct cards and construct them again.
How I can achieve this?
The cards will auto update their content when you make the call again, it is like refreshing your data.
I have made a simple example with a single card that shows data from this JSON Where I am calling the API first time in initState and then repeating the call each time I press on the FAB.
I am adding the index variable just to show you the updates (updating my single card with the next item in the list)
Also it is worth noting that I am handling the null or empty values poorly for the sake of time.
Also forget about the UI overflow ¯_(ツ)_/¯
class CardListExample extends StatefulWidget {
#override
_CardListExampleState createState() => new _CardListExampleState();
}
class _CardListExampleState extends State<CardListExample> {
Map cardList = {};
int index = 0;
#override
void initState() {
_getRequests();
super.initState();
}
_getRequests() async {
String url = "https://jsonplaceholder.typicode.com/users";
var httpClinet = createHttpClient();
var response = await httpClinet.get(
url,
);
var data = JSON.decode(response.body);
//print (data);
setState(() {
this.cardList = data[index];
this.index++;
});
print(cardList);
print(cardList["name"]);
}
#override
Widget build(BuildContext context) {
return new Scaffold(
floatingActionButton:
new FloatingActionButton(onPressed: () => _getRequests()),
appBar: new AppBar(
title: new Text("Card List Example"),
),
body: this.cardList != {}
? new ListView(children: <Widget>[
new Card(
child: new Column(
children: <Widget>[
new Row(
mainAxisAlignment: MainAxisAlignment.start,
children: <Widget>[
new Text(
cardList["name"] ?? '',
style: Theme.of(context).textTheme.display1,
),
new Text(
this.cardList['email'] ?? '',
maxLines: 50,
),
],
),
new Text(cardList["website"] ?? '')
],
),
),
])
: new Center(child: new CircularProgressIndicator()),
);
}
}
Yes, Answer from Aziza works.
Though I used the code as below :
void main() =>
runApp(new MaterialApp(
onGenerateRoute: (RouteSettings settings) {
switch (settings.name) {
case '/about':
return new FromRightToLeft(
builder: (_) => new _aboutPage.About(),
settings: settings,
);
}
},
home : new HomePage(),
theme: new ThemeData(
fontFamily: 'Poppins',
primarySwatch: Colors.blue,
),
));
class HomePage extends StatefulWidget{
#override
HomePageState createState() => new HomePageState();
}
class HomePageState extends State<HomePage>{
List data;
Future<String> getData() async{
var response = await http.get(
Uri.encodeFull(<SOMEURL>),
headers: {
"Accept" : "application/json"
}
);
this.setState((){
data = JSON.decode(response.body);
});
return "Success";
}
#override
void initState() {
// TODO: implement initState
super.initState();
this.getData();
}
#override
Widget build(BuildContext context){
return new Scaffold(
appBar : new AppBar(
title : new Text("ABC API"),
actions: <Widget>[
new IconButton( // action button
icon: new Icon(Icons.cached),
onPressed: () => getData(),
)],
),
drawer: new Drawer(
child: new ListView(
children: <Widget> [
new Container(
height: 120.0,
child: new DrawerHeader(
padding: new EdgeInsets.all(0.0),
decoration: new BoxDecoration(
color: new Color(0xFFECEFF1),
),
child: new Center(
child: new FlutterLogo(
colors: Colors.blueGrey,
size: 54.0,
),
),
),
),
new ListTile(
leading: new Icon(Icons.chat),
title: new Text('Support'),
onTap: () {
Navigator.pop(context);
Navigator.of(context).pushNamed('/support');
}
),
new ListTile(
leading: new Icon(Icons.info),
title: new Text('About'),
onTap: () {
Navigator.pop(context);
Navigator.of(context).pushNamed('/about');
}
),
new Divider(),
new ListTile(
leading: new Icon(Icons.exit_to_app),
title: new Text('Sign Out'),
onTap: () {
Navigator.pop(context);
}
),
],
)
),
body: this.data != null ?
new ListView.builder(
itemCount: data.length,
itemBuilder: (BuildContext context, int index){
return new Container(
padding: new EdgeInsets.fromLTRB(8.0,5.0,8.0,0.0),
child: new Card(
child: new Padding(
padding: new EdgeInsets.fromLTRB(10.0,12.0,8.0,0.0),
child: new Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
new ListTile(
enabled: data[index]['active'] == '1' ? true : false,
title: new Text(data[index]['header'],
style:Theme.of(context).textTheme.headline,
),
subtitle: new Text("\n" + data[index]['description']),
),
new ButtonTheme.bar(
child: new ButtonBar(
children: <Widget>[
new FlatButton(
child: new Text(data[index]['action1']),
onPressed: data[index]['active'] == '1' ? _launchURL :null,
),
],
),
),
],
),
),
),
);
},
)
:new Center(child: new CircularProgressIndicator()),
);
}
}
_launchURL() async {
const url = 'http://archive.org';
if (await canLaunch(url)) {
await launch(url);
} else {
throw 'Could not launch $url';
}
}
class FromRightToLeft<T> extends MaterialPageRoute<T> {
FromRightToLeft({ WidgetBuilder builder, RouteSettings settings })
: super(builder: builder, settings: settings);
#override
Widget buildTransitions(
BuildContext context,
Animation<double> animation,
Animation<double> secondaryAnimation,
Widget child) {
if (settings.isInitialRoute)
return child;
return new SlideTransition(
child: new Container(
decoration: new BoxDecoration(
boxShadow: [
new BoxShadow(
color: Colors.black26,
blurRadius: 25.0,
)
]
),
child: child,
),
position: new Tween(
begin: const Offset(1.0, 0.0),
end: const Offset(0.0, 0.0),
)
.animate(
new CurvedAnimation(
parent: animation,
curve: Curves.fastOutSlowIn,
)
),
);
}
#override Duration get transitionDuration => const Duration(milliseconds: 400);
}
The above code includes Navigation drawer, page navigation animation and also answer to the above question.

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