Author: Jay Mungara

I think this is one of the crucial and most important functionalities to read and write a file. Flutter also supports reading and writing files programmatically. You can use this tutorial as a reference to read and write any kind of text, doc, json or any other file types.

For this tutorial we are gonna cover following contents

• Read files from the assets
• Read files from your android or ios devices
• Write files from your android or ios devices

So some of you might think how to write files at assets folder. But, at the moment I’m writing this content I didn’t found any suitable way to do so from official flutter docs. I will keep checking this functionality and will update as soon as it will be available from official flutter docs.

First thing first, for implementing this file manipulating feature we are gonna use a third party package Path_Provider to access commonly used file locations on the file system.

Path_Provider is required only if you want to read and write files to your android/ios device locations.

Now, let’s get started with reading and writing files to your flutter projects.

Read files from the assets

To read files from assets you have to create or add your file(whether it is txt, doc, json etc.) in to assets folder. So first create a folder named “assets” inside your root project folder. Then create or add your file. For our sample I’m creating a file named “Toastguyz.txt” with some text inside it.

To access any files from assets in flutter, you need to register them inside pubspec.yaml file.

Pubspec.yaml file

assets:
  – assets/Toastguyz.txt

To access any files from assets in flutter, you need to register them inside pubspec.yaml file.

readFilesFromAssets() async {
  // Users can load any kind of files like txt, doc or json files as well
  String assetContent = await rootBundle.loadString('assets/Toastguyz.txt');

  print("assetContent : ${assetContent}");
}

You will need to use services dependency/APIs to use rootBundle related features.

import ‘package:flutter/services.dart’;

For our user case, I have accessed a text file using above method. You can also use other file types like doc, json and many more.

That’s it for read and write files from assets.

Read files from your android or ios devices

To read files from your custom android or ios location, you must have a file at that location. So, we will first create a file at some custom location in our android/ios devices and then we will try to read data from that file.

So to access custom file system location we will use a third party package called Path_Provider. It will help us to easily access file locations as per our requirements.

In our main.dart file, I have created a Home class inside which I have added a button to read files from android or ios device locations. Following is the method I have added to read files from custom device locations.

readFilesFromCustomDevicePath() async {
  // Retrieve "External Storage Directory" for Android and "NSApplicationSupportDirectory" for iOS
  Directory directory = Platform.isAndroid
      ? await getExternalStorageDirectory()
      : await getApplicationSupportDirectory();

  // Create a new file. You can create any kind of file like txt, doc , json etc.
  File file = await File("${directory.path}/Toastguyz.json").create();

  // Read the file content
  String fileContent = await file.readAsString();
  print("fileContent : ${fileContent}");
}

So for creating a file location I have used methods getExternalStorageDirectory() for android platform and getApplicationSupportDirectory() for ios platform to use recommended File locations for android and ios respectively.

We will use Path_Provider dependency/APIs for accessing file locations. Also, to check whether device platform is android or ios we will use io APIs. File manipulation related features also require io APIs.

import ‘dart:io’;
import ‘package:path_provider/path_provider.dart’;

We have created here a new json file “Toastguyz.json” using File.create() method. Then to read the content of the file we have an async method file.readAsString() which gives us the result of a file content as a String value.

This will give you the expected output as per our requirements.

Write files from your android or ios devices

To write files at your custom android or ios location, you must have a file at that location. So, we will first create a file at some custom location in our android/ios devices and then we will try to write data in to that file.

To access custom file system location we will use a third party package called Path_Provider.

In our main.dart file, I have created a Home class inside which I have added a button to write files at android or ios device locations. Following is the method I have added to write files to custom device locations.

writeFilesToCustomDevicePath() async {
  // Retrieve "External Storage Directory" for Android and "NSApplicationSupportDirectory" for iOS
  Directory directory = Platform.isAndroid
      ? await getExternalStorageDirectory()
      : await getApplicationSupportDirectory();

  // Create a new file. You can create any kind of file like txt, doc , json etc.
  File file = await File("${directory.path}/Toastguyz.json").create();

  // Convert json object to String data using json.encode() method
String fileContent=json.encode({
  "Website": {
    "Name": "Toastguyz",
    "Description": "Programming Tutorials",
  },
});

// You can write to file using writeAsString. This method takes string argument
// To write to text file we can use like file.writeAsString("Toastguyz file content");
return await file.writeAsString(fileContent);
}

So for creating a file location I have used methods getExternalStorageDirectory() for android platform and getApplicationSupportDirectory() for ios platform to use recommended File locations for android and ios respectively.

We will use Path_Provider dependency/APIs for accessing file locations and io APIs to check device platform device and perform File related operations.

import ‘dart:io’;
import ‘package:path_provider/path_provider.dart’;

We have created here a new json file “Toastguyz.json” using File.create() method. Then to write content in file we have an async method file.writeAsString() which takes String argument/parameter to write in to the file.

So to create json object as a String value will use json.encode() method as shown in the method. Then we will pass converted resultant String to our file.writeAsString()

You can also create any doc, txt or other file type and write according content in to it as per your requirements.

Now, we’re done with writing files to custom device location.

Feel free to ask your questions in the  comment section. Keep reading and commenting your suggestions to make toastguyz a better site to learn different programming languages.

Widgets are the reason why flutter, Google’s UI toolkit is unique and more elegant in many ways than other hybrid frameworks.

As per official documentation,

“Each and everything in flutter is Widget.”

In flutter, all the UI components or elements through which users can communicate are flutter widgets.

Widgets are built to design your flutter applications in most elegant and smoother way. Whatever the application UI a user can see and interact is thankful to flutter widgets.

Basically, widgets are used to build and describe the UI elements of a flutter application.

Flutter widgets are equivalent to Android Views, iOS UI Controllers, React Native Components and Ionic Controllers.

In flutter, Widgets are not just UI elements. Flutter widgets can update child elements, respond to user interaction, manage app state, act on lifecycle method events and so on.

Flutter has a wide range of cool widgets like, Text, AppBar, RaisedButton, IconButton, PageView, CircularProgressIndicator and many more.

In flutter, there are two types of widgets

• Stateless Widget
• Stateful Widget

Before, learning about stateful and stateless widgets. Let’s take a look on State

State

According to official documentation,

State is whatever data you need in order to rebuild your UI at any moment in time while your app is running.

State is the structural representation of your UI which keeps track of app’s assets, all the variables on which screen UI depends, fonts, textures, animation state and so on.

Now, you we have idea about state we can move to the introduction of stateless and stateful widgets.

Stateless Widget

A widget which can’t change/mutate it’s state is known as Stateless Widget.

A stateless widget never changes/redraw its UI. Icon, Text, IconButton are examples of Stateless Widget.

Syntax of a Stateless Widget

import ‘package:flutter/material.dart’
class StatelessSample extends StatelessWidget {
  final String title;
  StatelessSample(this.title);
  
  @override
  Widget build(BuildContext context) {
    // Your Stateless Widget UI Goes Here
    return Scaffold(body: Center(child: Text("Stateless Widget")));
  }
}

Every stateless widget has a build method for drawing/rendering their widget UI. Stateless widget can also have a constructor method to get the parameters from parent widgets.

We use Stateless widgets to display static content.

To create a Stateless widget, you need to extend your class from Stateless Widget.

We need to use material.dart APIs to use built-in material design widgets in flutter.

We will learn more about stateless widget lifecycle methods and flutter syntax in upcoming tutorials.

Stateful Widget

A widget which can change/mutate it’s state is known as Stateful Widget.

Stateful widget can redraw it’s UI using a built-in setState() method for a stateful widget.

It has more complex lifecycle methods than stateless widgets as stateful widget’s state can be modified.

To create a Stateful widget you will need to create two classes.

1. A Stateful class – creates state of the stateful widget
2. A State class – updates UI of the stateful class based on state changes

A Stateful class should be extended from a StatefulWidget class.

class StatefulSample extends StatefulWidget {
}

A stateful class must implement createState() method.

@override
StatefulSampleState createState() => StatefulSampleState();

createState() method will need the reference of a new corresponding State class which keeps track of state of the stateful class.

// keeps track of state of StatefulSample class
class StatefulSampleState extends State {

}

Obviously, a build method is required to draw the UI of the widget. But, all the methods will take place in the state class instead of stateful class.

In this way if the state of the widget changes then Build method gets called again and re-renders the widget with updated state properties.

class StatefulSampleState extends State {
@override
Widget build(BuildContext context) {
return Container();
}
}

To change the state of the stateful widget, flutter provides built-in setState() method.

Syntax of a Stateful Widget

class StatefulSample extends StatefulWidget {
  final String title;
  StatefulSample(this.title);

  @override
  StatefulSampleState createState() => StatefulSampleState();
}

class StatefulSampleState extends State<StatefulSample> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: RaisedButton(
          child: Text(widget.title),
          onPressed: () {
            setState(() {
              // Calling setState() method will update the state of the UI and re-render the widget
            });
          },
        ),
      ),
    );
  }
}

A Stateful widget can also have a constructor in its stateful class. We can access properties and methods of a stateful class to its corresponding state class using widget variable.

Note :

“widget” variable can be accessed from methods only in state class.

For ex :

for accessing title property of a stateful class to corresponding state class inside build method using widget.title

So whenever we require dynamic content in widget which might change over time we should use Stateful widget.

Also, we will learn more about stateful widget lifecycle methods and flutter syntax in upcoming tutorials.

So this was the brief introduction on flutter widgets and its types.

Feel free to ask your questions in the comment section. Keep reading and commenting your suggestions to make toastguyz a better site to learn different programming languages.

I have decided to write the flutter project structure for developers who have not been used to android or iOS package structure or even for beginners who want to be familiar with the flutter environement.

In last tutorial, we have learned to create and run your flutter project. Yet, if you don’t know about it please visit our flutter proect creation and deployment tutorial.

Before explaining flutter project structure i am going to introduce an important tools in flutter known as Pub.

Pub

Pub is the package manager for the dart programming language containing libraries and packages for flutter.

Pub is the package management tool which has list of commands for configuring, debugging, testing and managing your flutter project.

So initially when you create any flutter project you will find out the flutter project/package structure as below :

We are going to discuss all the important packages and files listed in your project structure as above.

Initially you will see two main packages. One is your Project Root Package (In above image, fluttersample) and other one is External Libraries.

Project Root Package

Project package will contain all the packages and files related to your flutter coding, testing and maintenance.

.idea

.idea package contains project configuration settings like dart sdk, flutter plugins, project workspace and many more. All the configuration files will be stored in xml file forms. Generally, you will never need to approach this package.

android

android package will contain all the packages and files related to your native android app. If you’ve ever worked with android platform you will find this package familiar. Whenever you want to implement any android specific feature you have to work with this package directories.

In android, AndroidManifest.xml is the core file containing all the essential information about configuration details of your android app.

ios

Similar to android package, ios package will also contain all the packages and files related to your native ios app. Whenever you want to implement any native ios specific feature you have to work in this package directories.

In ios, Info.plist is the core file containing all the essential information about configuration details of your ios app.

lib

This is our main flutter package in which we have to write our flutter code. By default, when you create a project you will find out a main.dart file in your lib folder. So, this main.dart file will have a main function from where your flutter app execution starts.

Also, lib is the package in which you are going to create and write all the dart files (as flutter uses dart as its development language) containing your app source code.

By default, main.dart file will have some code written in it (you can say this a flutter’s hello world application). So that you can test and run something you can interact in your flutter app.

Test

This package will contain files for writing and running software tests to ensure that your flutter app is working correctly before release. By default, it will contain a dart file named as widget_test.dart for software testing.

.flutter-plugins

This file lists the information about third party packages you uses in your flutter project.

.gitignore

As name suggests, this hidden file stores lists of different files which you don’t want to upload to your git system while pulling or pushing your source code to git system.

.metadata

.metadata file contains the information about the flutter properties like stable sdk channel, project type etc.

.packages

.packages file contains information about all the dart packages included inside the external libraries in your flutter project.

<appname.iml>

This file contains configuration information about the packages and modules used by the IDE.

pubspec.lock

This file conatins detailed information(like, dependency name, description, meta, source, version and many more information) about all the dart packages included in your flutter project.

pubspec.yaml

pubspec.yaml is an essential file containing all the flutter project related information like project name, project details, sdk version details, third packages or dependencies used in the project, assets(like images, files, fonts) you want to use in your project etc.

README.md

This is an option file provided for developer reference. Any developer can add different kinds of information about flutter project so that other developers can read and understand it. This file is like comments in program or say explanatory documentation about flutter project.

Okay, so we have done our part o understanding the flutter project structure. You will get used to this project structure. So, don’t worry and get going through our tutorials.

Our next tutorial is flutter widgets covering what widget is and how they works to build your app UI.

If you find out our flutter tutorials then share it with your friends and comment down your suggestions to help us in making our tutorials more interesting for other users.

Feel free to ask your questions in the comment section. Keep reading and commenting your suggestions to make toastguyz a better site to learn different programming languages.

This tutorial talks about how to create your flutter project and run it to your android or iOS device. If you have not done environment setup then visit our Flutter Environment Setup.

First ensure that you have installed Dart and Flutter plugins in your IDE or not.

Install Dart and Flutter Plugins/Extensions

First open your preferred IDE.

In welcome screen, click on Configure > Plugins.

Then in Plugins window, Click on Browse repositories, search the Dart and Flutter plugins to install.

We will create and run flutter project based on our choice of our development tools.

1. Android Studio/IntelliJ Idea
2. VS Code
3. Terminal & Editor

Create a flutter project

Create project In Android Studio or IntelliJ IDEA

To create an app in android studio or intellij open the IDE and in welcome screen click on Create new project.

In the next screen, you will find out list of packages like Java, Android, Maven, Gradle, Dart, Flutter, Kotlin etc.

Then select Flutter package and provide the Flutter SDK path. Then select Next.

In next screen, select Project Name as per your choice and Project location at your preferred location in the disk.

Select other important details like Organization, your preferred Android Language and iOS Language as well.

Then click on Finish to create new flutter project.

Create project In VS Code

Open VS Code IDE, select View > Command Pallete (Ctrl + Shift + P).

Type Flutter and select the Flutter:New Project.

Enter project name of your choice and press Enter.

Then select the preferred location for saving your project in the disk.

Wait till proect creation completes.

Create project using Terminal

Open terminal and move to the folder or directory in the disk where you want to create your project.

Then use flutter create command to create your flutter project.

flutter create myapp

In above command, myapp will be the name of your flutter project.

After creating your flutter project in your desired IDE you will need to run your app.

Run flutter app

Run in android studio / intellij

Locate the Toolbar in android stuydio or intellij.

You can select your device in which you want to run from Target Selector option in toolbar. Toolbar also have other useful features like Run, Debug, Hot Reload, Attach and Stop to support run and test functions in your app.

If there is no devices listed, then create one from Tools > Android > AVD Manager.

Now, click on Run icon in the toolbar to run your flutter app.

Run in VS Code

Locate the VS Code status bar (the blue bar at the bottom of IDE).

Select a device from Device Selector area.

Then select Debug > Start Debugging or press F5 to run your flutter app.

Run app using terminal

Run your flutter app using command,

flutter run

After your app build gets completed, You’ll find the starter hello world flutter application running in your device as below.

Also, your project will have core folder/package structure as below with all the projects you create.

Flutter-app/
.idea
android
ios
lib
test
Other important files like .gitignore, .metadata, .packages, pubspec.lock, pubspec.yaml

The package for coding your flutter application will be lib package. Lib package will have a main.dart file from where your flutter application execution starts.

In further tutorials, we will deeply understand about the project structure and syntax structure for flutter development.

For now, let’s take a look at how you can use hot reload feature in flutter framework.

Hot Reload

To use hot reload feature in app, your app must be open at the same time.

Ctrl + S is the command to hot reload your app.

With this instructions, you’re done for the basic flutter set up. Still if you find any issues comment down your questions and suggestions or visit the official documentation.

Our next tutorial is about the flutter project structure which explains how flutter directories and packages are organised and used in flutter project. So stay tuned with us for reading more interesting flutter tutorials.

Feel free to ask your questions in the comment section. Keep reading and commenting your suggestions to make toastguyz a better site to learn different programming languages.

I think now you are in love with flutter and want to take part in this flutter journey.

Before starting your flutter development you will need to install some tools and editors or IDEs to run and test your flutter codes and applications.

Let’s get started with the flutter environment setup based on different operating systems.

• Flutter for Windows
• Flutter for Mac
• Flutter for Linux

We have referred official flutter documentation for setting up the flutter environment setup. We have tried to gather all the OS specific install and setup procedure at one place. Still if you find any issue comment down and we are here to help you as soon as possible.

To setup flutter environment we need to download and configure Flutter SDK (Software development kit) which is set of tools or libraries required for creating applications for android and iOS platforms.

I will try to explain each and every possible aspect for setting up required tools and IDEs for flutter development. But, still if you find any issue please comment down your questions and we will try to help you as soon as possible.

To download and setup flutter SDK for different operating systems visit the official website and download the flutter SDK version for windows, mac or linux OS respectively.

Flutter for Windows

For windows, extract the downloaded zip file for SDK and find the “flutter” named folder inside it and place it to desired location for further configuration.

Update environment variables

To run flutter commands in terminal in general, you have to set-up environment variables in windows.

From the start menu search bar, type ‘env’ and select Edit environment variables.

Inside User variables check if there is an entry named as Path

If the Path entry exists, add the full path to flutter SDK till flutter\bin; using “;” as a separator after existing values.

If the Path entry does not exist, create a new user variable named Path with the full path to flutter SDK till flutter\bin; as its value.

Still if you find any issue in setting up flutter SDK visit the official website

Flutter for Linux

For linux, extract the downloaded file for SDK and find the “flutter” named folder inside it and place it to desired location for further configuration.

Update flutter path

To run flutter commands in terminal in general, you have to add flutter tools to your path in Linux.
 export PATH=”$PATH:`pwd`/flutter/bin”

Still if you find any issue in setting up flutter SDK visit official website

Flutter for Mac

For Mac, extract the downloaded zip file for SDK and find the “flutter” named folder inside it and place it to desired location for further configuration.

Update flutter path

To run flutter commands in terminal in general, yo have to add flutter tools to your path in Mac.
 export PATH=”$PATH:`pwd`/flutter/bin”

Still if you find any issue in setting up flutter SDK visit official website

Run Flutter Doctor

After SDK Setup, to check if everything is okay run flutter doctor command in terminal. You can also checkout if anything is missing to set up flutter framework in your machine using the following command,

flutter doctor

If everything is working fine then we have to work on android and iOS setup to run our flutter project.

Android Setup For Running Flutter Apps

Flutter depends on full installation of Android Studio to use its platform dependencies. However, we can use another IDEs for flutter coding.

First download and install Android Studio from official website

Start android studio and go through the installation wizard and download and setup all the tools required for android platform setup like Android SDK, Android SDK Platform-Tools, and Android SDK Build-Tools etc.

For setting up any IDE (like Android Studio, Intellij IDEA etc) for your flutter coding you have to install dart and flutter plugins.

Install Dart and Flutter Plugins

First open your preferred IDE.

In welcome screen, click on Configure > Plugins.

Then in plugins window, click on Browse repositories, search the Dart and Flutter plugins to install.

Restart IDE after installing plugins and you’re done.

To run flutter app on android either you require to setup android emulator or to setup real android device.

Setup Android Emulator

In Android Studio, go to Tools > Android > AVD Manager > Create Virtual Device.

Choose a device configuration as per your requirements and select Next.

Select at least one system image for running your emulator for any of the android versions like Nougat, Oreo, Pie etc.

Under emulated performance, select Hardware – GLES 2.0 to enable hardware acceleration.

Verify the AVD configurations and click on Finish.

Now, your emulator is ready to run. Click Run in the toolbar and select the device emulator to run your app. It will display your app running on android emulator device with selected OS version and configurations.

Setup Android Device

Enable Developer Options and USB Debugging on your device.

Install the Google USB Driver (for windows user only).

Plug in your real device in to your machine with USB cable. If any dialog appears for machine authorisation authenticate it to access your device to run your app.

To check out if flutter has recognised any devices or not run “flutter devices” command in terminal. It will list out all the connected devices to your machine.

Select run option in toolbar to run flutter app in your real android device.

Still if you find any issue in setting up android setup visit the link here for respective OS
For Windows visit official website
For Linux visit official website
For Mac visit official website

iOS Setup

You cannot install XCode IDE (iOS app development IDE) other than Mac. Ultimately, it’s not possible to run your ios app in windows. Therefore, you will require a mac OS installed in your machine to build and run ios apps.

So to build and run flutter apps for iOS, you will need a mac OS with Xcode 9.0 and higher.

Install Xcode

Download and Install Xcode IDE from official website or Mac App Store

To run flutter app on ios either you require to setup iOS simulator or deploy to real iOS device.

Setup iOS Simulator

On your Mac, open simulator by using the following command.
open -a Simulator

Ensure that your simulator is using a 64-bit phone (i.e., iPhone 5s or later) by checking the settings in the simulator’s Hardware > Device menu.

Depending on your computer’s screen size, high-screen-density iOS simulator might overflow your screen. Set the device scale under the Window > Scale menu in the iOS simulator.

Run/Deploy app to iOS devices

To run your flutter app to a real device you’ll need an apple account and some additional tools.

Install homebrew from official website

Install additional tools for running flutter apps to iOS device by running the following commands.

brew install –HEAD usbmuxd
brew link usbmuxd
brew install –HEAD libimobiledevice
brew install ideviceinstaller ios-deploy cocoapods
pod setup

Complete signing flow to configure your project.

Open the default Xcode workspace in your project.

In Xcode, select the Runner project in the naviagtion panel.

In the Runner target settings page, selct your Development Team under General > Signing > Team. After selecting a development team, Xcode creates and downloads a Development Certificate then it registers your device with your account. At last it creates and downloads a provisioning profile (if required).

To start your iOS development project in Xcode, you need to sign in with your apple ID.

Remember that development and testing is supported for any apple ID.

While you attach a physical iOS device to run your app, you will need to trust both your Mac and the Development Certificate on that device. Select Trust in the dialog appear while connect your iOS device for the first time.

Then go to the Settings app in your device to select General > Device Management to trust your development certificate.

If automatic signing fails in Xcode, then verify project’s General > Identity > Bundle Identifier value is unique.

Now, you’re done to run your flutter app in your iOS device.

So in upcoming tutorials, we will also learn how to create a flutter project and how to run flutter app in your android and iOS device.

Below is the list of popular IDEs which you can use for flutter app development.

• Android Studio visit official website
• Xcode visit official website
• IntelliJ IDEA visit official website
• VSCode visit official website

My personal suggestion for developers coming from the app development background is Android Studio or Xcode or Intellij IDEA and for developers coming from the web background is VS code.

I have tried to explain environment setup for flutter development, still if you find any issues then comment down your questions and suggestions to make our tutorials more readable and efficient for other users.

Feel free to ask your questions in the comment section. Keep reading and commenting your suggestions to make toastguyz a better site to learn different programming languages.

Toastguyz has been overwhelmed by the support of users who are continuously visiting our site and motivating us to write more interesting tutorials. So we have come up with a new tutorial series based on hybrid app development which is flutter framework.

Welcome to our first tutorial on flutter framework.

What is Flutter?

Flutter is Google’s UI toolkit or framework for quickly building beautiful and feature-rich applications for mobile, web and desktop from a single codebase.

Basically, flutter is not a programming language but a cross-platform app development framework or SDK. It is similar to android framework as android is not a language but framework to develop android application in kotlin or java language. Flutter has dart as its core development language to built cross-platform applications.

It is an open-source cross-platform mobile application development framework to create android and iOS application with a single codebase to have native like performance and feel.

The first version of flutter was known by codename “Sky” and ran on Android operating system. Flutter is developed by Google and community using C, C++, Dart and Skia graphics engine. Google released flutter’s first stable release in May 2017 globally.

At present, Flutter is an evolving framework which focuses on faster app-development, beautiful expressive UI and great user experience.

Now, you will be thinking about what is unique about flutter and why you should pick up flutter for app development choice.

So, let me explain this by showcasing flutter’s top features and extra-ordinary capabilities.

Flutter Top Features

Adaptive Framework

Flutter uses dart as its core language for mobile development which is easy to learn.

Dart can be easily mastered if you have worked with C, C++, Java, C# or Swift ever. Also, flutter widgets and functions are way easier to understand and implement in production level apps.

Single codebase

With the help of flutter, we can create android and ios apps from single codebase which ultimately leads to less resources and low budget for the customers.

Faster app development (due to hot reload)

Hot reload is extremely helpful when developers make minor changes or bug fixing and they don’t need to run app every time from scratch to end for testing features. Which improves app development time as well as efficiency.

Faster and Efficient compilation

The dart language supports Ahead of Time compilation (AOT) to provide better performance and startup time to flutter apps. Flutter’s hot reload feature is also thankful to dart’s Just In Time compilation (JIT).

Expressive and Flexible UI

I think this is the most attractive feature flutter has over other hybrid platforms. As each and everything we see and interact with is a widget in flutter. The user interface and design features follows the material design and cupertino style elements to provide expressive and attractive UI elements. Flutter also provides the flexibility to create custom widgets or say UI elements of your choice using feature-rich APIs and widgets available.

Native like feel and features

The apps developed in flutter provides a natural look and feel regardless of screen size and orientation. Also, flutter has a large set of widgets developed as per the platform-specific conventions using the fast C++ based 2D rendering skia graphics library. Flutter widgets incorporate all the native specific differences such as scrolling, navigation, icons, fonts and many more to provide pure feels like native iOS or native android platform.

Reactive Framework

Flutter is a reactive framework due to its core language Dart which supports modern features like fast object allocation, garbage collector, state management, future and stream APIs, etc. Flutter follows “unidirectional data flow” architecture for reactive programming and state management. In this kind of reactive programming, application reacts to the user inputs (That ultimately changes the properties and variables of the class to change the state of the screen or view programmatically)  and the UI gets re-rendered when the state changes.

Third-Party Plugins

Flutter supports many feature-rich third-party plugins for custom widgets or custom features like camera, local storage, video capture, maps, pageview, etc to make flutter coding easier.

Platform-specific code

Developers can easily write platform-specific code for the features they want for their native platforms which might not be developed in flutter yet.

Flutter Framework Architecture

Basically, flutter framework architecture is built in a different way to reflect faster UI changes with better performance. Everything in flutter is widgets. So every widget is rendered on skia graphics canvas and sent to the native platforms. Native platforms show the rendered canvas in the UI and communicate with the widgets as required.

Flutter is actually a kind of native platform framework because flutter doesn’t require any javascript bridge to inflate platform-specific UI widgets.

Framework architecture in flutter has mainly three layers,

• Flutter framework
• Flutter engine
• Platform layer

Flutter framework

Flutter framework is built upon the base of dart language having vast support of material design and cupertino style widgets to create UI components for native platforms. Widgets are the basic building blocks in flutter apps.

Flutter widgets are not only UI components but, also handles the states of the components, events and business logic to perform specific operations in the app.

Flutter framework is responsible for rendering UI widgets, state management, animations, gestures, controlling execution flow and many more.

Flutter Engine

Flutter engine is the next layer for rendering the widgets using a C++ based 2D graphics library known as skia. In this layer, Dart VM is present to provide an execution environment for converting your high level dart code in to native platform executable code. Flutter engine runs inside the native platform shells(i.e., Android, iOS, Embedded systems) to render appropriate look and feel to the widgets and communicate according to the specific platforms.

Platform layer

This is the last layer which converts your native executable code in user interaction. Flutter provides native specific shells (i.e, Android Shell and iOS shell) that host the Dart VM for giving access to the platform-specific native APIs, hardware communication and hosting the platform-specific canvas or surface in which widgets or UI components are drawn. Platform level gives access to the flutter framework to keep track of platform-specific lifecycle events, communication with the system events and much more.

This type of high level framework architecture makes flutter smoother, faster and feature-rich platform to quickly build beautiful and performance rich applications.

What is unique about flutter?

Flutter is flexible, customizable and smoother with feature rich APIs and great architecture design.

It doesn’t require any javascript bridge to communicate with native platforms and components.

Comes with a set of beautiful widgets or UI components without depending on native platforms.

It has better reactive views with “unidirectional data flow” architecture.

Flutter provides hot reload feature which helps developers to quickly test and view the application changes.

Flutter provides hot reload feature which helps developers to quickly test and view the application changes.

Communication between application created in flutter and OS is as minimum as possible because flutter itself take cares of all the things like UI rendering, widget events, and hardware communication, etc.

Apps developed in flutter has better compatibility, greater performance, buttery UI and smoother control with great fun.

I hope this great features have convinced you to learn flutter.

So, we can move to the prerequisites for learning flutter framework.

Flutter Prerequisites

Now, If you’re thinking to learn flutter then your conscious mind, hard work, and interest are must throughout this flutter series.

For learning flutter, any prior knowledge to any of this conventional programming languages like C, C++, Dart, Java, C# or Swift can be a plus point. Don’t worry if you don’t work with any language prior. Just start learning flutter’s core development language dart as we have already created a series on dart language covering basic and advanced concepts. So you can easily learn dart language from there in just a week or two.

Conclusion

I hope flutter can be a good choice for your career subject or app development framework as it is getting a revolutionary response from all over the globe. As flutter can develop android and iOS apps from a single codebase it is approachable for customers who require better performance with great UI in less budget. Ultimately, flutter is a great framework introduced by google developers for easily creating customizable and flexible cross-platform apps.

Feel free to ask your questions in the comment section. Keep reading and commenting your suggestions to make toastguyz a better site to learn different programming languages.