Ekhlass/Flutter_Documentation · Datasets at Hugging Face

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<topic_end>
<topic_start>
Navigating to another app
In UIKit, to send the user to another application,
you use a specific URL scheme.
For the system level apps, the scheme depends on the app.
To implement this functionality in Flutter,
create a native platform integration, or use an
existing plugin, such as url_launcher.<topic_end>
<topic_start>
Manually pop back
Calling SystemNavigator.pop() from your Dart code
invokes the following iOS code:If that doesn’t do what you want, you can create your own
platform channel to invoke arbitrary iOS code.<topic_end>
<topic_start>
Handling localization
Unlike iOS, which has the Localizable.strings file,
Flutter doesn’t currently have a dedicated system for handling strings.
At the moment, the best practice is to declare your copy text
in a class as static fields and access them from there. For example:
<code_start>class Strings {
static const String welcomeMessage = 'Welcome To Flutter';
}<code_end>
You can access your strings as such:
<code_start>Text(Strings.welcomeMessage);<code_end>
By default, Flutter only supports US English for its strings.
If you need to add support for other languages,
include the flutter_localizations package.
You might also need to add Dart’s intl
package to use i10n machinery, such as date/time formatting.To use the flutter_localizations package,
specify the localizationsDelegates and
supportedLocales on the app widget:
<code_start>import 'package:flutter/material.dart';
import 'package:flutter_localizations/flutter_localizations.dart';
class MyWidget extends StatelessWidget {
const MyWidget({super.key});
@override
Widget build(BuildContext context) {
return const MaterialApp(
localizationsDelegates: <LocalizationsDelegate<dynamic>>[
// Add app-specific localization delegate[s] here
GlobalMaterialLocalizations.delegate,
GlobalWidgetsLocalizations.delegate,
],
supportedLocales: <Locale>[
Locale('en', 'US'), // English
Locale('he', 'IL'), // Hebrew
// ... other locales the app supports
],
);
}
}<code_end>
The delegates contain the actual localized values,
while the supportedLocales defines which locales the app supports.
The above example uses a MaterialApp,
so it has both a GlobalWidgetsLocalizations
for the base widgets localized values,
and a MaterialWidgetsLocalizations for the Material widgets localizations.
If you use WidgetsApp for your app, you don’t need the latter.
Note that these two delegates contain “default” values,
but you’ll need to provide one or more delegates
for your own app’s localizable copy,
if you want those to be localized too.When initialized, the WidgetsApp (or MaterialApp)
creates a Localizations widget for you,
with the delegates you specify.
The current locale for the device is always accessible
from the Localizations widget from the current context
(in the form of a Locale object), or using the Window.locale.To access localized resources, use the Localizations.of() method
to access a specific localizations class that is provided by a given delegate.
Use the intl_translation package to extract translatable copy
to arb files for translating, and importing them back into the app
for using them with intl.For further details on internationalization and localization in Flutter,
see the internationalization guide, which has sample code
with and without the intl package.<topic_end>
<topic_start>
Managing dependencies
In iOS, you add dependencies with CocoaPods by adding to your Podfile.
Flutter uses Dart’s build system and the Pub package manager
to handle dependencies. The tools delegate the building of the
native Android and iOS wrapper apps to the
respective build systems.While there is a Podfile in the iOS folder in your
Flutter project, only use this if you are adding native
dependencies needed for per-platform integration.
In general, use pubspec.yaml to declare external dependencies in Flutter.
A good place to find great packages for Flutter is on pub.dev.<topic_end>
<topic_start>
ViewControllers
This section of the document discusses the equivalent
of ViewController in Flutter and how to listen to
lifecycle events.<topic_end>
<topic_start>
Equivalent of ViewController in Flutter
In UIKit, a ViewController represents a portion of user interface,
most commonly used for a screen or section.
These are composed together to build complex user interfaces,
and help scale your application’s UI.
In Flutter, this job falls to Widgets.
As mentioned in the Navigation section,
screens in Flutter are represented by Widgets since
“everything is a widget!”

<topic_end>

<topic_start>

Navigating to another app

In UIKit, to send the user to another application,

you use a specific URL scheme.

For the system level apps, the scheme depends on the app.

To implement this functionality in Flutter,

create a native platform integration, or use an

existing plugin, such as url_launcher.<topic_end>

<topic_start>

Manually pop back

Calling SystemNavigator.pop() from your Dart code

invokes the following iOS code:If that doesn’t do what you want, you can create your own

platform channel to invoke arbitrary iOS code.<topic_end>

<topic_start>

Handling localization

Unlike iOS, which has the Localizable.strings file,

Flutter doesn’t currently have a dedicated system for handling strings.

At the moment, the best practice is to declare your copy text

in a class as static fields and access them from there. For example:

<code_start>class Strings {

static const String welcomeMessage = 'Welcome To Flutter';

}<code_end>

You can access your strings as such:

<code_start>Text(Strings.welcomeMessage);<code_end>

By default, Flutter only supports US English for its strings.

If you need to add support for other languages,

include the flutter_localizations package.

You might also need to add Dart’s intl

package to use i10n machinery, such as date/time formatting.To use the flutter_localizations package,

specify the localizationsDelegates and

supportedLocales on the app widget:

<code_start>import 'package:flutter/material.dart';

import 'package:flutter_localizations/flutter_localizations.dart';

class MyWidget extends StatelessWidget {

const MyWidget({super.key});

@override

Widget build(BuildContext context) {

return const MaterialApp(

localizationsDelegates: <LocalizationsDelegate<dynamic>>[

// Add app-specific localization delegate[s] here

GlobalMaterialLocalizations.delegate,

GlobalWidgetsLocalizations.delegate,

],

supportedLocales: <Locale>[

Locale('en', 'US'), // English

Locale('he', 'IL'), // Hebrew

// ... other locales the app supports

],

);

}

}<code_end>

The delegates contain the actual localized values,

while the supportedLocales defines which locales the app supports.

The above example uses a MaterialApp,

so it has both a GlobalWidgetsLocalizations

for the base widgets localized values,

and a MaterialWidgetsLocalizations for the Material widgets localizations.

If you use WidgetsApp for your app, you don’t need the latter.

Note that these two delegates contain “default” values,

but you’ll need to provide one or more delegates

for your own app’s localizable copy,

if you want those to be localized too.When initialized, the WidgetsApp (or MaterialApp)

creates a Localizations widget for you,

with the delegates you specify.

The current locale for the device is always accessible

from the Localizations widget from the current context

(in the form of a Locale object), or using the Window.locale.To access localized resources, use the Localizations.of() method

to access a specific localizations class that is provided by a given delegate.

Use the intl_translation package to extract translatable copy

to arb files for translating, and importing them back into the app

for using them with intl.For further details on internationalization and localization in Flutter,

see the internationalization guide, which has sample code

with and without the intl package.<topic_end>

<topic_start>

Managing dependencies

In iOS, you add dependencies with CocoaPods by adding to your Podfile.

Flutter uses Dart’s build system and the Pub package manager

to handle dependencies. The tools delegate the building of the

native Android and iOS wrapper apps to the

respective build systems.While there is a Podfile in the iOS folder in your

Flutter project, only use this if you are adding native

dependencies needed for per-platform integration.

In general, use pubspec.yaml to declare external dependencies in Flutter.

A good place to find great packages for Flutter is on pub.dev.<topic_end>

<topic_start>

ViewControllers

This section of the document discusses the equivalent

of ViewController in Flutter and how to listen to

lifecycle events.<topic_end>

<topic_start>

Equivalent of ViewController in Flutter

In UIKit, a ViewController represents a portion of user interface,

most commonly used for a screen or section.

These are composed together to build complex user interfaces,

and help scale your application’s UI.

In Flutter, this job falls to Widgets.

As mentioned in the Navigation section,

screens in Flutter are represented by Widgets since

“everything is a widget!”