This framework attracts the attention of many companies and development teams, its growth has taken place in a massive community of millions of people. In fact, Flutter is an open-source software development kit (SDK) created by Google and released in May 2017. It combines two important parts:
- An SDK: a collection of software development tools in one installable package, that are going to facilitate the creation of your applications by having a compiler, debugger…
- A Framework: a collection of reusable UI widgets that you can customize for your own needs.
What is more, Flutter is surrounded by extensive documentation provided by its owner which contains what every beginner needs to find like tutorials, examples etc. What can Flutter do? it allows to build an app for Android, iOS, Windows, Mac, Linux and Google Fuchsia using a single codebase with the quality of native apps, especially in Ui/Ux. What makes Flutter unique? compared to other cross-platform development applications like React Native that require bridges between their code and native elements, Flutter eliminates additional processing steps that decrease performance making it noticeably faster.
So, in this article, I want to recommend a multi-step roadmap for beginners to become a Flutter developer.
1. Pick a language:
The primary programming language of Flutter apps is Dart, which was founded by Google in 2011. It is a multi-platform asynchronous programming language that is typed, object-oriented, and client-optimized. So, what makes Dart stand out from other programming languages?
- Optimized for UI: Dart is a programming language designed specifically for creating user interfaces, with features such as sound null safety, which protects you from null exceptions at runtime and increases productivity by removing all unnecessary testing.
- Maximum productivity: the code is reloaded immediately thanks to hot reload, which is accomplished by a JIT compilation provided by the Dart virtual machine.
- Fast on all platforms: Dart also uses an AOT compiler, which compiles your code into native ARM or x64 machine code for fast startup and consistent runtime performance.
Therefore, I advise a beginner to start studying Dart before diving into the fundamentals of Flutter.
Some useful learning resource links:
- A tour of the Dart language.
- Introduction to Dart Programming Language
- Dart – Variables
- Operators in Dart
Practice, Practice !
Using an online DartPad code editor for beginners, you can practice your code and enhance your Dart language skills.
2. Flutter development environment
Before you start developing, you need know which IDE is the finest. So, in my opinion, and that of many other developers, I recommend utilizing Android Studio, IntelliJ, or VSCode. In reality, these IDEs assist you in developing sophisticated apps by providing code completion tools, syntax highlighting, widget editing assistance, runtime and debugging support, and other features.
3. Flutter fundamentals
After being familiar with Dart, it is now time to begin with Flutter Basics.
– Flutter Widgets:
Widgets are the primary building elements of every UI in a Flutter app, the entire screen is a widget, a button is a widget, text is a widget, and so on.
– Widget types:
Flutter widgets are classified into two types: stateless widgets and stateful widgets. Stateless widgets are immutable, so they cannot change their appearances or properties while the program is running or when an action is performed on the screen, such as an icon, text, etc. Stateful widgets, on the other hand, are a wonderful way to add interaction to your view. In fact, they can change their appearance in reaction to a user-triggered event or data update. To do so, you should override the createState() method, which returns the widget’s state.
Check out the following sites for more information on the various types of Flutter widgets:
When you use the previous two widgets, you’ll obtain a widget tree that you can inspect with the Flutter inspector. When you want to send data to the next widget in the tree, you must use the constructor of each widget to pass the data from one to the other, which is a time-consuming job, particularly for large apps.
The InheritedWidget solves the above problem by being able to persist data and communicate it to the widget tree without having to call each widget’s constructor.
Please check out the following websites to learn more about how this widget works and how to implement it:
– Flutter’s essential widgets:
Flutter has a set of strong basic widgets such as Text, Icon, Row, Stack, Container, and others. These are the widgets that you must know before developing your first application and that will assist you in creating your customized widgets.
When exploring different Flutter widgets, you will most likely come across two types of Google design guidelines.
– Flutter design guidelines:
Any Flutter app is either Material or Cupertino designed. Google built the Material design system to support any platform, not just Android, but also iOS, web, and desktop apps. Indeed, this design includes a number of components and technologies that support best standards in user interface design. However, if you want your app to look like a regular iOS app, you should use the Cupertino library. For each of these design principles, Flutter offers a variety of widgets, so you may check out the following links to become more familiar with Flutter design elements:
– Navigation and Routing:
The majority of Flutter apps have multiple screens, therefore you should transition between them to access a different one and pass data as needed. In this situation, Flutter gives us the Navigator class, whose primary function is to control the navigation of your application.
- Navigate to a new screen and back
- Send data to a new screen
- Return data from a screen
- Navigate with named routes
- Pass arguments to a named route
So far, what we’ve seen in navigation is suitable for small projects. However, as the project grows, we want to manage all routes in one location using a powerful solution. As a result, the Flutter community created the auto-route package, which uses code generation to simplify route setup.
– Use of Assets:
To make apps more enjoyable, we use custom assets like images, videos, fonts and audios. Each element is a static file that must be included in the application. Remember to only include the files that are required to keep the application size as little as possible.
4. Advanced UI:
Using the basic Flutter widgets or your own custom widgets, you can construct static user interfaces up to this point. However, most apps also include dynamic screens, such as a splash screen with a colorful loading animation, a dynamic list for data analysis, and others. So it’s time to start learning how to design dynamic screens that conform to your specifications.
– Dynamic user interface:
As we’ve already mentioned, the primary principle of the Flutter Framework is the use of widgets. Almost everything is a widget, including elements that are hidden from view like Rows, Columns, GridViews, and ListViews that order your visible items. Several layouts are offered in Flutter, and which one you choose depends on how you want to constrain the visible widgets.
To practice creating layouts, see the following documentation:
– Add interactivity to your app:
So far, you can create a static widget-based screen to expose certain information or a dynamic layout to organize your elements. However, it is essential that your app interacts with user actions in various forms, such as gestures, taps, and so on.
Flutter creates several stateful widgets to accomplish this, such as Checkbox, Slider, GestureDetector, Text Field, and others. These widgets are capable of meeting your needs.
Developing dynamic user interfaces with user interactivity is an important step at this point, but if you want people to have fun while using your app, adding animation is the way to go. Using animation to attract users’ attention to parts of an app is an excellent way to do it. Flutter provides various ready-to-integrate animation widgets to help with animation implementation, such as: AnimatedContainer, Hero widget, AnimatedOpacity, AnimatedSize, AnimatedPositioned, and so on. Furthermore, you can construct your own animation by combining several additional widgets provided by the framework.
– Responsive UI:
The Flutter framework’s primary purpose is to construct applications for many operating systems from a single code base. This means that your program can be displayed on several screens of varying sizes, ranging from a watch to a huge device. In this case, you might think about designing a user interface that adjusts to different screen sizes smoothly.
As a solution, Flutter offers two fundamental ways of creating a responsive app:
Other useful widgets and classes for creating a responsive UI:
Here are a few resources for more information, including contributions from the Flutter community:
- Developing for Multiple Screen Sizes and Orientations in Flutter
- Build Responsive UIs in Flutter
- Making Cross-platform Flutter Landing Page Responsive
Once you’re comfortable with UI development, you should start learning about API call integration. Flutter API calls can be made using a variety of packages such as http, dio, retrofit, chopper, and so on. You can start with any of them, but it’s always a good idea to start with http because it’s the base package from which all other packages are built.
You need to learn:
- Dart concepts for asynchronous programming
- HTTP request methods (post,put,get,delete..)
- How to use REST APIs with Flutter
- How to convert JSON data to Dart objects
- Asynchronous programming: futures, async, await
- Asynchronous programming: Streams
- Available HTTP Methods
- Fetch data from the internet
- JSON and serialization
6. Data Persistence:
You may need to maintain data in local memory in order to directly access its value when needed. For this situation, the Flutter community provides you with several packages. However, for security reasons, you should always pay attention to the data to be saved.
- Shared-preferences: The shared preference package is used to store data locally on the device as a key-value pair. You should also be aware that this package does not save data in encrypted form.
- Flutter-secure-storage: To solve the previous issue of saving values with better security, the Flutter community introduced the Flutter-secure-storage package, which is based on the IOS keychain and Android EncryptedSharedPreferences with V5.0.0 and more.
If your application must store a large amount of data while also querying it, It is suggested that you use a local database, and don’t worry, you have various options:
7. The Art of State Management:
You can control the state of your screens at first by using the setState () function proposed by the Flutter team, but as your application grows in size and complexity, managing the state of your application becomes more difficult. Suppose you have an application with two screens and you want to pass data between them. It’s easy. You can simply pass it through the constructors. However, if you have a huge application and need to transmit the value from page one to page five, the prior solution requires you to send the appropriate value to every screen constructor until you reach page five. State management comes in handy in this situation! Its primary role is to centralize all of the states of multiple UI components in order to handle data flow across the application.
Famous flutter state management libraries:
Through this blog, I covered all of the important topics that will help you become a Flutter developer .
Happy coding until next time.