Flutter: The Initial Guide to this Framework!

  • By Yokesh Shankar
  • 19-01-2024
  • Mobile App Development
flutter guide
Until recently, one of the main difficulties in developing applications for smartphones was the need to write practically the same code, with some adaptations, for Android and iOS. The main objective of the  Flutter framework  is to eliminate this problem, as it allows the creation of applications for these systems from the same source code.
And that's not all. It is also possible to develop desktop applications on Linux and macOS platforms. Therefore, this is a very comprehensive technology that offers a series of features to facilitate software development services without the need to rewrite code. 

What is Flutter?

Flutter is an  open source framework , developed by Google, that allows the development of native applications for Android and iOS . The first version of the tool was launched in December 2018, with the aim of developing hybrid applications and competing with other similar technologies, such as React Native and Ionic.
Flutter uses Dart as a basis for developing its applications . It is a multi-paradigm language, created in 2011 by Google, with the intention of competing with JavaScript. It allows the development of client-server applications and smartphone applications. In Flutter, Dart is used with the object-oriented programming pattern.

Get to know the Dart language

Dart  is a programming language that is very similar to the  C  and Java languages. It was created by Google and released to the market in October 2011. It supports tougher typing like C but can also be used in a similar way to Javascript.
As mentioned earlier,  it is the language used in the Flutter framework and has gained a lot of notoriety for it . However, the Dart has much more to offer than just that. Like any other language, we can create any type of application, from a web server to a Windows application.
Therefore, the Dart language is very versatile and easy to understand for beginner developers, thus becoming an emerging language in recent years.

Understand the architecture of the Flutter Framework

Since Flutter is an SDK (Software Development Kit, which in Portuguese means Software Development Kit), we have  a complete ecosystem in our hands , with a rendering engine, pre-made widgets, integration APIs and much more.

Flutter Framework

The framework is made from the Dart language and  offers broad support for Material Design and the Cupertino style . With this we have the implementation of Widgets, animations, state management and a few other factors that influence the dynamics of the user interface.

Framework Engine

The Engine is written in the  C++ language for greater performance. In it,  we have the implementation of Flutter's essential functionalities , including text layout, files and network management. Dart is used to compile and run the applications and Google's Skia library is used for graphics rendering.

Flutter platform layer

At this layer,  we have the app's conversation with the cell phone's operating system , Android or IOS. In fact, it is responsible for controlling the life cycle of programs, managing screen size, thread handling and the messaging platform.

What are the top 5 features of Flutter?

Flutter contains a series of features that make it a powerful tool for building applications for mobile devices. Check out some of them below.

1. Allows cross-platform development

The Flutter framework can be installed on Windows, Linux, macOS and Chrome OS . Therefore, on any of these platforms it is possible to develop applications for Android and iOS. Furthermore, it can be used in different tools, such as the Visual Studio Code code editor and the Android Studio IDE.

2. Enables the development of native applications

As we mentioned, developing for different platforms requires writing duplicate code, especially the layer that contains business rules. One of Flutter's features is that it allows the creation of native applications for different operating systems — including Android and iOS —, which eliminates this need.
It is worth mentioning that it also allows the development of Flutter desktop applications on Linux and macOS. Furthermore, the project for developing Flutter web applications is in beta.

3. Allow access to native features

Another feature of Flutter is that it allows the use of native operating system resources , such as camera, geolocation, etc. When the application is  compiled , it is transformed into a native application according to the corresponding platform chosen.

4. Offers higher performance

By offering access to the operating system's native resources, there is greater performance when running applications. Another reason for this is because  it does not require an intermediate layer to access these resources , that is, the application is written in Dart, but converted to the operating system's native machine language.

5. Componentization and reactive programming

In Flutter, we have some features that we can find in competing tools. In Android we have the way of assembling the Layout, in Xamarin we have the unification of code for distribution on different platforms and in React we obtain reactive programming and componentization, which in Flutter are referred to as  Widgets .
Everything we find in Flutter are  Widgets , so everything in Flutter is components. We can make a comparison with today's web applications. This way we know that a text is a Widget, a button is also a Widget and even a behavior is also a Widget.
Other than that, Flutter comes standard with  Live Reload  built-in. This way, if there is any type of change in any project file, the application changes in real time, in addition to storing the states of the variables at the time of the update so that no data is lost when saving a file. .

What are the main applications of Flutter? Know what it is used for?

Flutter  is used to facilitate mobile development through a toolkit . By having the open source code created by Google, we are able to create applications for Android and IOS, in addition to being the main method for developing programs for Google Fuchsia.
One of the promises of the Flutter development team is the creation of web applications. As of 2021, web platform support is in beta but functional.

What are the advantages of using Flutter?

Some of the features presented in the previous topic already represent benefits of using Flutter, such as greater performance and access to native resources. However, there are other advantages to using this tool. Check out some of them below.

Simple to learn and simple to use

Flutter is a very modern tool and you can see this from its day-to-day development. In a simple way and with little code, we can now create applications for cell phones.  If you've ever used Java, Swift, or React Native, you'll realize that Flutter is very different.
One of the most enviable aspects of Flutter is the use of little code to create a truly native app.

Saving time and money

As Flutter is a cross-platform development tool,  we were able to create an Android and an IOS application in the same code base . Multiplatform development is the best way to save time and money, as we can shorten the development process for different platforms.
We also have the issue of licensing, which in some other frameworks, like Xamarin, we end up having to pay to use the IDE, for example. In the case of Flutter, everything is free, from the SDK to the IDEs, and you can even choose which text editor you will use to develop the applications.

It is an open source framework

Having  open source tools helps reduce application development costs , as you will not need to pay for a usage license. In addition to Google, which is the main developer, there is a community of developers who help answer questions on different platforms, such as Stack Overflow, Gitter, among others.

High productivity

Flutter allows the development of applications for different platforms. This means greater productivity for the development team. However, it uses the Dart language, which is not very popular. According to the 2020 Stack Overflow survey on the most popular technologies, the Dart language is used by only 4% of respondents.
The JavaScript language is used by 67.7% of respondents. Because of this, if you are a beginner, it is best to start learning how to develop applications using technologies such as React Native / JavaScript, which are already more established in the market.
However, the Flutter framework and the Dart language should also be part of a complement to this learning, as it is a technology that has been gaining ground in the market.

Good documentation

It is very important that new tools have good documentation, but unfortunately this is not always the case.
Fortunately, Flutter provides its developers with documentation rich in details and examples. In it, we have many ready-made code recipes and also a catalog with all the  Widgets  that Flutter has.

What are the disadvantages of Flutter?

Lack of third-party libraries

Third-party libraries and packages play a big role in the life of a software developer, speeding up the process of creating screens and reducing code made from scratch. These libraries are mostly open source, easy to use, and heavily tested.
For many popular and older technologies, it is not that difficult to find the package needed for your project, while for newer ones it is  often a problem .
Today, there are more than 15 thousand packages listed in the official Flutter documentation and this number continues to grow. Obviously it is smaller than its competitor, React Native, but it is more than enough.
In fact, as we already mentioned, there are many pre-defined Widgets in Flutter that can already play a big role in the development flow, so we don't need many third-party tools.

The Dart Language

Because it is a very new language and uses the paradigms of Object Oriented Programming,  we end up having a big problem finding new people to develop . Compared to other technologies, especially some old ones like JavaScript, C#, and Java, we ended up realizing Dart's defeat. We must take this into consideration when choosing Flutter as our mobile development tool.
Even though it is a relatively easy language,  for beginner developers this impression is not true and many end up learning languages ​​​​that have the possibility of creating programs for the web and mobile , such as JavaScript.

Application size

Users have limited storage on their phones, so modern apps are expected to be relatively small in size. To achieve this, programmers try to avoid animations, reduce package sizes, and even compress images.
Since we use the pre-defined Widgets instead of using third-party ones, we have a size slightly larger than 4 MB in a Flutter application , which is definitely larger than a native application in Java (539 KB) and Kotlin (550 KB) , this is for a basic application. Although, we must be fair, competitors share the same problem: in the case of Xamarin, we have an average size of 16 MB and in React Native 7 MB.

What are the main companies using Flutter?

Flutter has seen a huge rise among developers and custom software development company. Below, you can see some companies that use this tool.
- Nubank: Adopted in 2019 by the emerging digital bank, it is one of the most complete and interesting cases on this list.
- Tencent: Chinese giant that uses Flutter in several applications.
- Google Assistant: Flutter helps power a growing number of Google Assistant apps.
- Ebay: The Ebay Motors app is a powerful resource for browsing, buying and selling vehicles.
- Google Ads: Another Google application. In it, the user can manage, optimize and follow all their ads from the convenience of a cell phone.
- Alibaba: Flutter helped bring a new app to life for one of the world's largest online marketplaces.
- And our Government has migrated its applications from INSS, etc. to Flutter.

Last Updated in February 2024

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Yokesh Shankar

Glad you are reading this. I’m Yokesh Shankar, the COO at Sparkout Tech, one of the primary founders of a highly creative space. I’m more associated with digital transformation solutions for global issues. Nurturing in Fintech, Supply chain, AR VR solutions, Real estate, and other sectors vitalizing new-age technology, I see this space as a forum to share and seek information. Writing and reading give me more clarity about what I need.

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