Languages: English (this file), Brazilian Portuguese, Spanish,Polish.
- Communication and support channels:
- About Get
- Installing
- Counter App with GetX
- The Three pillars
- How to contribute
- Utils
- Breaking changes from 2.0
- Why Getx?
Discord (English and Portuguese)
- GetX is an extra-light and powerful solution for Flutter. It combines high performance state management, intelligent dependency injection, and route management in a quick and practical way.
- GetX is not for everyone, its focus is (performance) on the minimum consumption of resources (look the benchmarks), (productivity) using an easy and pleasant syntax and (organization) allowing the total decoupling of the View from the business logic.
- GetX will save hours of development, and will extract the maximum performance that your application can deliver, being easy for beginners, and accurate for experts.
- Navigate without
context, opendialogs,snackbarsorbottomsheetsfrom anywhere in your code, Manage states and inject dependencies in an easy and practical way. - Get is secure, stable, up-to-date, and offers a huge range of APIs that are not present on default framework.
- GetX is not
bloated. It has a multitude of features that allow you to start programming without worrying about anything, but each of these features are in separate containers, and are only started after use. If you only use State Management, only State Management will be compiled. If you only use routes, nothing from the state management will be compiled. You can compile the benchmark repository, and you will see that using only Get state management, the application compiled with Get has become smaller than all other applications that have only the state management of other packages, because nothing that is not used will be compiled into your code, and each GetX solution was designed to be extra lightweight. The merit here also comes from Flutter's AOT which is incredible, and manages to eliminate unused resources like no other framework does.
GetX makes your development productive, but want to make it even more productive? Add the extension GetX extension to your VSCode. Not available in other IDEs for now.
Add Get to your pubspec.yaml file:
dependencies:
get:Import get in files that it will be used:
import 'package:get/get.dart';The "counter" project created by default on new project on Flutter has over 100 lines (with comments). To show the power of Get, I will demonstrate how to make a "counter" changing the state with each click, switching between pages and sharing the state between screens, all in an organized way, separating the business logic from the view, in ONLY 26 LINES CODE INCLUDING COMMENTS.
- Step 1: Add "Get" before your materialApp, turning it into GetMaterialApp
void main() => runApp(GetMaterialApp(home: Home()));-
Note: this does not modify the MaterialApp of the Flutter, GetMaterialApp is not a modified MaterialApp, it is just a pre-configured Widget, which has the default MaterialApp as a child. You can configure this manually, but it is definitely not necessary. GetMaterialApp will create routes, inject them, inject translations, inject everything you need for route navigation. If you use Get only for state management or dependency management, it is not necessary to use GetMaterialApp. GetMaterialApp is necessary for routes, snackbars, internationalization, bottomSheets, dialogs, and high-level apis related to routes and absence of context.
-
Note²: This step in only necessary if you gonna use route management (
Get.to(),Get.back()and so on). If you not gonna use it then it is not necessary to do step 1 -
Step 2: Create your business logic class and place all variables, methods and controllers inside it. You can make any variable observable using a simple ".obs".
class Controller extends GetxController{
var count = 0.obs;
increment() => count.value++;
}- Step 3: Create your View, use StatelessWidget and save some RAM, with Get you may no longer need to use StatefulWidget.
class Home extends StatelessWidget {
// Instantiate your class using Get.put() to make it available for all "child" routes there.
final Controller c = Get.put(Controller());
@override
Widget build(context) => Scaffold(
// Use Obx(()=> to update Text() whenever count is changed.
appBar: AppBar(title: Obx(() => Text("Clicks: " + c.count.string))),
// Replace the 8 lines Navigator.push by a simple Get.to(). You don't need context
body: Center(child: RaisedButton(
child: Text("Go to Other"), onPressed: () => Get.to(Other()))),
floatingActionButton:
FloatingActionButton(child: Icon(Icons.add), onPressed: c.increment));
}
class Other extends StatelessWidget {
// You can ask Get to find a Controller that is being used by another page and redirect you to it.
final Controller c = Get.find();
@override
Widget build(context){
// Access the updated count variable
return Scaffold(body: Center(child: Text(c.count.string)));
}
}Result:
This is a simple project but it already makes clear how powerful Get is. As your project grows, this difference will become more significant.
Get was designed to work with teams, but it makes the job of an individual developer simple.
Improve your deadlines, deliver everything on time without losing performance. Get is not for everyone, but if you identified with that phrase, Get is for you!
There are currently several state managers for Flutter. However, most of them involve using ChangeNotifier to update widgets and this is a bad and very bad approach to performance of medium or large applications. You can check in the official Flutter documentation that ChangeNotifier should be used with 1 or a maximum of 2 listeners, making it practically unusable for any application medium or large.
Get isn't better or worse than any other state manager, but that you should analyze these points as well as the points below to choose between using Get in pure form (Vanilla), or using it in conjunction with another state manager.
Definitely, Get is not the enemy of any other state manager, because Get is a microframework, not just a state manager, and can be used either alone or in conjunction with them.
Get has two different state managers: the simple state manager (we'll call it GetBuilder) and the reactive state manager (who has the package name, GetX)
Reactive programming can alienate many people because it is said to be complicated. GetX turns reactive programming into something quite simple:
- You won't need to create StreamControllers.
- You won't need to create a StreamBuilder for each variable
- You will not need to create a class for each state.
- You will not need to create a get for an initial value.
Reactive programming with Get is as easy as using setState.
Let's imagine that you have a name variable and want that every time you change it, all widgets that use it are automatically changed.
This is your count variable:
var name = 'Jonatas Borges';To make it observable, you just need to add ".obs" to the end of it:
var name = 'Jonatas Borges'.obs;And in the UI, when you want to show that value and update the screen whenever tha values changes, simply do this:
Obx (() => Text (controller.name));That's all. It's that simple.
See an more in-depth explanation of state management here. There you will see more examples and also the difference between the simple stage manager and the reactive state manager
Amateur Coder did an awesome video about state management! Link: Complete GetX State Management
You will get a good idea of GetX power.
If you are going to use routes/snackbars/dialogs/bottomsheets without context, GetX is excellent for you too, just see it:
Add "Get" before your MaterialApp, turning it into GetMaterialApp
GetMaterialApp( // Before: MaterialApp(
home: MyHome(),
)Navigate to new screen:
Get.to(NextScreen());To close snackbars, dialogs, bottomsheets, or anything you would normally close with Navigator.pop(context);
Get.back();To go to the next screen and no option to go back to the previous screen (for use in SplashScreens, login screens and etc.)
Get.off(NextScreen());To go to the next screen and cancel all previous routes (useful in shopping carts, polls, and tests)
Get.offAll(NextScreen());Noticed that you didn't had to use context to do any of these things? That's one of the biggest advantages of using Get route management. With this, you can execute all these methods from within your controller class, without worries.
Get work with named routes and also offer a lower level control over your routes! There is a in-depth documentation here
Amateur Coder did an excellent video that cover route management with Get! here is the link: Complete Getx Navigation
Get has a simple and powerful dependency manager that allows you to retrieve the same class as your Bloc or Controller with just 1 lines of code, no Provider context, no inheritedWidget:
Controller controller = Get.put(Controller()); // Rather Controller controller = Controller();- Note: If you are using Get's State Manager, pay more attention to the bindings api, which will make easier to connect your view to your controller.
Instead of instantiating your class within the class you are using, you are instantiating it within the Get instance, which will make it available throughout your App. So you can use your controller (or class Bloc) normally
Tip: Get dependency management is decloupled from other parts of the package, so if for example your app is already using a state manager (any one, it doesn't matter), you don't need to rewrite it all, you can use this dependency injection with no problems at all
controller.fetchApi();Imagine that you have navigated through numerous routes, and you need a data that was left behind in your controller, you would need a state manager combined with the Provider or Get_it, correct? Not with Get. You just need to ask Get to "find" for your controller, you don't need any additional dependencies:
Controller controller = Get.find();
//Yes, it looks like Magic, Get will find your controller, and will deliver it to you. You can have 1 million controllers instantiated, Get will always give you the right controller.And then you will be able to recover your controller data that was obtained back there:
Text(controller.textFromApi);See a more in-depth explanation of dependency management here
Want to contribute to the project? We will be proud to highlight you as one of our collaborators. Here are some points where you can contribute and make Get (and Flutter) even better.
- Helping to translate the readme into other languages.
- Adding documentation to the readme (a lot of Get's functions haven't been documented yet).
- Write articles or make videos teaching how to use Get (they will be inserted in the Readme and in the future in our Wiki).
- Offering PRs for code/tests.
- Including new functions.
Any contribution is welcome!
Please do not use any higher level widget than GetMaterialApp in order to update it. This can trigger duplicate keys. A lot of people are used to the prehistoric approach of creating a "ThemeProvider" widget just to change the theme of your app, and this is definitely NOT necessary with Get.
You can create your custom theme and simply add it within Get.changeTheme without any boilerplate for that:
Get.changeTheme(ThemeData.light());If you want to create something like a button that changes the theme with onTap, you can combine two Get APIs for that, the api that checks if the dark theme is being used, and the theme change API, you can just put this within an onPressed:
Get.changeTheme(Get.isDarkMode? ThemeData.light(): ThemeData.dark());When darkmode is activated, it will switch to the light theme, and when the light theme is activated, it will change to dark.
If you want to know in depth how to change the theme, you can follow this tutorial on Medium that even teaches the persistence of the theme using Get:
- Dynamic Themes in 3 lines using Get - Tutorial by Rod Brown.
// give the current args from currentScreen
Get.arguments
// give arguments of previous route
Get.previousArguments
// give name of previous route
Get.previousRoute
// give the raw route to access for example, rawRoute.isFirst()
Get.rawRoute
// give access to Rounting API from GetObserver
Get.routing
// check if snackbar is open
Get.isSnackbarOpen
// check if dialog is open
Get.isDialogOpen
// check if bottomsheet is open
Get.isBottomSheetOpen
// remove one route.
Get.removeRoute()
// back repeatedly until the predicate returns true.
Get.until()
// go to next route and remove all the previous routes until the predicate returns true.
Get.offUntil()
// go to next named route and remove all the previous routes until the predicate returns true.
Get.offNamedUntil()
//Check in what platform the app is running
GetPlatform.isAndroid
GetPlatform.isIOS
GetPlatform.isWeb
// Equivalent to the method: MediaQuery.of(context).size.height, but they are immutable.
Get.height
Get.width
// Gives the current context of navigator.
Get.context
// Gives the context of the snackbar/dialog/bottomsheet in the foreground anywhere in your code.
Get.contextOverlay
// Note: the following methods are extensions on context. Since you
// have access to context in any place of your UI, you can use it anywhere in the UI code
// If you need a changeable height/width (like browser windows that can be scaled) you will need to use context.
context.width
context.height
// gives you the power to define half the screen now, a third of it and so on.
//Useful for responsive applications.
// param dividedBy (double) optional - default: 1
// param reducedBy (double) optional - default: 0
context.heightTransformer()
context.widthTransformer()
/// similar to MediaQuery.of(context).size
context.mediaQuerySize()
/// similar to MediaQuery.of(context).padding
context.mediaQueryPadding()
/// similar to MediaQuery.of(context).viewPadding
context.mediaQueryViewPadding()
/// similar to MediaQuery.of(context).viewInsets;
context.mediaQueryViewInsets()
/// similar to MediaQuery.of(context).orientation;
context.orientation()
/// check if device is on landscape mode
context.isLandscape()
/// check if device is on portrait mode
context.isPortrait()
/// similar to MediaQuery.of(context).devicePixelRatio;
context.devicePixelRatio()
/// similar to MediaQuery.of(context).textScaleFactor;
context.textScaleFactor()
/// get the shortestSide from screen
context.mediaQueryShortestSide()
/// True if width be larger than 800
context.showNavbar()
/// True if the shortestSide is smaller than 600p
context.isPhone()
/// True if the shortestSide is largest than 600p
context.isSmallTablet()
/// True if the shortestSide is largest than 720p
context.isLargeTablet()
/// True if the current device is Tablet
context.isTablet()GetMaterialApp configures everything for you, but if you want to configure Get manually.
MaterialApp(
navigatorKey: Get.key,
navigatorObservers: [GetObserver()],
);You will also be able to use your own Middleware within GetObserver, this will not influence anything.
MaterialApp(
navigatorKey: Get.key,
navigatorObservers: [
GetObserver(MiddleWare.observer) // Here
],
);You can create Global settings for Get. Just add Get.config to your code before pushing any route or do it directly in your GetMaterialApp
GetMaterialApp(
enableLog: true,
defaultTransition: Transition.fade,
opaqueRoute: Get.isOpaqueRouteDefault,
popGesture: Get.isPopGestureEnable,
transitionDuration: Get.defaultDurationTransition,
defaultGlobalState: Get.defaultGlobalState,
);
Get.config(
enableLog = true,
defaultPopGesture = true,
defaultTransition = Transitions.cupertino
)Amateur Coder did an awesome video about utils, storage, bindings and other features! Link: GetX Other Features
1- Rx types:
| Before | After |
|---|---|
| StringX | RxString |
| IntX | RxInt |
| MapX | RxMax |
| ListX | RxList |
| NumX | RxNum |
| DoubleX | RxDouble |
RxController and GetBuilder now have merged, you no longer need to memorize which controller you want to use, just use GetxController, it will work for simple state management and for reactive as well.
2- NamedRoutes Before:
GetMaterialApp(
namedRoutes: {
'/': GetRoute(page: Home()),
}
)Now:
GetMaterialApp(
getPages: [
GetPage(name: '/', page:()=> Home()),
]
)Why this change? Often, it may be necessary to decide which page will be displayed from a parameter, or a login token, the previous approach was inflexible, as it did not allow this. Inserting the page into a function has significantly reduced the RAM consumption, since the routes will not be allocated in memory since the app was started, and it also allowed to do this type of approach:
GetStorage box = GetStorage();
GetMaterialApp(
getPages: [
GetPage(name: '/', page:(){
return box.hasData('token') ? Home() : Login();
})
]
)1- Many times after a Flutter update, many of your packages will break. Sometimes compilation errors happen, errors often appear that there are still no answers about, and the developer needs to know where the error came from, track the error, only then try to open an issue in the corresponding repository, and see its problem solved. Get centralizes the main resources for development (State, dependency and route management), allowing you to add a single package to your pubspec, and start working. After a Flutter update, the only thing you need to do is update the Get dependency, and get to work. Get also resolves compatibility issues. How many times a version of a package is not compatible with the version of another, because one uses a dependency in one version, and the other in another version? This is also not a concern using Get, as everything is in the same package and is fully compatible.
2- Flutter is easy, Flutter is incredible, but Flutter still has some boilerplate that may be unwanted for most developers, such as Navigator.of(context).push (context, builder [...]. Get simplifies development. Instead of writing 8 lines of code to just call a route, you can just do it: Get.to(Home()) and you're done, you'll go to the next page. Dynamic web urls are a really painful thing to do with Flutter currently, and that with GetX is stupidly simple. Managing states in Flutter, and managing dependencies is also something that generates a lot of discussion, as there are hundreds of patterns in the pub. But there is nothing as easy as adding a ".obs" at the end of your variable, and place your widget inside an Obx, and that's it, all updates to that variable will be automatically updated on the screen.
3- Ease without worrying about performance. Flutter's performance is already amazing, but imagine that you use a state manager, and a locator to distribute your blocs/stores/controllers/ etc. classes. You will have to manually call the exclusion of that dependency when you don't need it. But have you ever thought of simply using your controller, and when it was no longer being used by anyone, it would simply be deleted from memory? That's what GetX does. With SmartManagement, everything that is not being used is deleted from memory, and you shouldn't have to worry about anything but programming. You will be assured that you are consuming the minimum necessary resources, without even having created a logic for this.
4- Actual decoupling. You may have heard the concept "separate the view from the business logic". This is not a peculiarity of BLoC, MVC, MVVM, and any other standard on the market has this concept. However, this concept can often be mitigated in Flutter due to the use of context. If you need context to find an InheritedWidget, you need it in the view, or pass the context by parameter. I particularly find this solution very ugly, and to work in teams we will always have a dependence on View's business logic. Getx is unorthodox with the standard approach, and while it does not completely ban the use of StatefulWidgets, InitState, etc., it always has a similar approach that can be cleaner. Controllers have life cycles, and when you need to make an APIREST request for example, you don't depend on anything in the view. You can use onInit to initiate the http call, and when the data arrives, the variables will be populated. As GetX is fully reactive (really, and works under streams), once the items are filled, all widgets that use that variable will be automatically updated in the view. This allows people with UI expertise to work only with widgets, and not have to send anything to business logic other than user events (like clicking a button), while people working with business logic will be free to create and test the business logic separately.
This library will always be updated and implementing new features. Feel free to offer PRs and contribute to them.