Does inserting all providers in main affect performance? Is it a better option to put individual providers in the middle of the tree where they are needed?
When injecting many values in big applications, Provider can rapidly become pretty nested:
Provider<Something>(
create: (_) => Something(),
child: Provider<SomethingElse>(
create: (_) => SomethingElse(),
child: Provider<AnotherThing>(
create: (_) => AnotherThing(),
child: someWidget,
),
),
),
To:
MultiProvider(
providers: [
Provider<Something>(create: (_) => Something()),
Provider<SomethingElse>(create: (_) => SomethingElse()),
Provider<AnotherThing>(create: (_) => AnotherThing()),
],
child: someWidget,
)
**
The behavior of both examples is strictly the same. MultiProvider only changes the appearance of the code.
**
Try importing 'package:provider/provider.dart' as statemanagement; and use multi provider as statemanagement.MultiProvider(...), and use Provider as statemanagement.Provider(....) worked on my code
import 'package:flutter/material.dart';
import 'package:provider/provider.dart' as statemanagement;
import 'models/model_provider.dart';
import 'modules/screen_root.dart';
void main() {
runApp(const MyApp());
}
class MyApp extends StatelessWidget {
const MyApp({super.key});
#override
Widget build(BuildContext context) {
return statemanagement.MultiProvider(
providers: [
statemanagement.Provider<ModelProvider>(
create: ((_) => ModelProvider())),
],
child: MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Multi Provider',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const ScreenRoot(),
),
);
}
}
Related
I am using this screen util package that helps handle the responsiveness of the app on different screen size and I am also using provider both of them require MaterialApp as child but I don't know how to go about it instead I did this and now I'm having some issues navigating in the app.
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MultiProvider(providers: [
ChangeNotifierProvider(create: (_)=>
TestimonyVeiwModel()
),
],
child: ScreenUtilInit(
builder:() => MaterialApp(
title: 'Stea app',
theme: ThemeData();
I prefer using this way
return ScreenUtilInit(
builder: () => MultiProvider(
providers: [...],
child: MaterialApp(
//...
),
),
);
I use providers in my app, below code is working but doesnt look right :)
Looking for some help how reformat the code to only use child once..
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
ChangeNotifierProvider(
create: (_) => AppProvider(),
),
ChangeNotifierProvider(
create: (_) => ThemeProvider(true),
),
],
child: Consumer<AppProvider>(
builder: (ctx, providerApp, _) => Container(
child: Consumer<ThemeProvider>(
builder: (ctx, providerTheme, _) => MaterialApp(
debugShowCheckedModeBanner: false,
theme: providerTheme.getTheme(),
home: Splash(),
),
),
),
),
);
}
}
I have started using PROVIDER to manage state in my app. I followed tutorials and wrapped my Material app with ChangeNotifierProvider.
Here's the code :
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return ChangeNotifierProvider(
create: (BuildContext context) => ListsProvider(),
child: MaterialApp(
title: 'WordsApp',
theme: ThemeData(
primarySwatch: Colors.blue,
),
initialRoute: StartingPage.id,
routes: {
StartingPage.id: (context) => StartingPage(),
RegistrationScreen.id: (context) => RegistrationScreen(),
},
),
);
}
}
This provider called "ListsProvider" takes care of "providing" lists that need to be displayed on different screens.
I have now created a second provider which I called "user_data_provider" and I now need to add it to my app too. It will take care of providing user data to many different screens.
How can I do that ?
To achive this you can use Multiprovider as shown below
Add this to the top of your app. If you need these obj everywhere.
#override
Widget build(BuildContext context) {
return MultiProvider(
providers: [
ChangeNotifierProvider<user_data_provider>(
create: (_) => user_data_provider(),
),
ChangeNotifierProvider<ListsProvider>(
create: (_) => ListsProvider(),
),
],
child: Builder(
builder: (BuildContext context) {
return MaterialApp(
//YOur code goes here
);
},
),
);
I'm new to Flutter. I have encountered the following problem where I have no idea how to add another changenotifierprovider to my app.dart. Before that I already have the EntryProvider(), Now I wish to add another provider called EnterProvider(). Below is my coding for app.dart:
class App extends StatelessWidget {
#override
Widget build(BuildContext context) {
return ChangeNotifierProvider(
create: (context) => EntryProvider(),
child: MaterialApp(
home: WelcomeBackPage(),
theme: ThemeData(
accentColor: Colors.orangeAccent,
primaryColor: Colors.black,
textTheme: GoogleFonts.openSansTextTheme(),
),
debugShowCheckedModeBanner: false,),
);
}
}
Could anyone help me out on this?
You can try MultiProvider .
MultiProvider(
providers: [
Provider<Something>(create: (_) => Something()),
Provider<SomethingElse>(create: (_) => SomethingElse()),
Provider<AnotherThing>(create: (_) => AnotherThing()),
],
child: someWidget,
)
If I only want a widget and its children have specific Provider but not in whole app, how do I achieve that ?
// not this
void main() {
runApp(
MultiProvider(
providers: [
ChangeNotifierProvider(create: (context) => CartModel()),
Provider(create: (context) => SomeOtherClass()),
],
child: MyApp(),
),
);
}
You just need to wrap MultiProvider to the Widget you want.
Like this:
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: MultiProvider(
providers: [Provider(create: (context) => TestModel(index: 1)),],
child: MyHomePage(title: 'Flutter Demo Home Page')
),
);
}
}
You can wrap this widget with the provider and can be used as
final _myProvider=Provider.of<MyProvider>(context, listen: false);
or using
Consumer<MyProvider>(
builder: (BuildContext context, MyProvider myProvider, Widget child) {
return child;
),