Coding Style

The important part of good code is good style

Search by using Rex

Search and replace toBean by Rex : static .? toBean(.?) => .?(.?);

Useful

• Always try to use existing feature or function

// not recommend
var result = double.parse('some string');
//1. This code could be have error or crash app 
//   when string value not able to case into double

import 'package:infinity_core/core.dart';

var result = 'some string'.secureDouble;
// 1. use existing build in function, 
// if some string have invalid format it function will take care for us.

• Early return when function with condition

  if(true){
      return;
  }
  if(false){
      return;
  }

• Use extension, extension, extension everywhere

  // not recommend
      AppBar(
          backgroundColor: Theme.of(this).colorScheme.inversePrimary,
          title: const Text('API URL', textAlign: TextAlign.center),
      );
      ElevatedButton(
          onPressed: _settingOnPressed,
          style: ButtonStyle(backgroundColor: WidgetStateProperty.all<Color>(Theme.of(this).colorScheme.inversePrimary)),
          child: Text(_isEditApi ? 'Done' : 'Change API'),
      );
  // This code have use inversePrimary which is primary color, and this color base on context and use multiple place. 
  // do not copy and write redundancy 
  
  
  // recommend
      extension BuildContextExtension on BuildContext {
        Color get colorPrimary => context.colorPrimary;
      };
      AppBar(
          backgroundColor: context.colorPrimary,
          title: const Text('API URL', textAlign: TextAlign.center),
      );
      ElevatedButton(
          onPressed: _settingOnPressed,
          style: ButtonStyle(backgroundColor: WidgetStateProperty.all<Color>(context.colorPrimary)),
          child: Text(_isEditApi ? 'Done' : 'Change API'),
      );
  // To resolve about case we can create other extension for context. 
  // next time we only need to write context.colorPrimary.

• Put it as private if we use it only in the same file.

  class MyClass {
    String _privateVariable = "This is private";
    
    String publicVariable = "This is public";
  
    void _privateMethod() {
      print("This is a private method.");
    }
  
    // Public method (accessible from other files)
    void publicMethod() {
      print("This is a public method.");
      // Calling the private method from within the same file
      _privateMethod();
    }
  }
  
  void main() {
    MyClass myClass = MyClass();
  
    print(myClass.publicVariable);
    myClass.publicMethod();
  
    // Accessing the private variable and method will result in a compile-time error
    // print(myClass._privateVariable); // Error: '_privateVariable' isn't defined
    // myClass._privateMethod();        // Error: '_privateMethod' isn't defined
  }
  

• Try not to cast or repeated declare type

  void main() {
    var myClass = MyClass();  // Using 'var' instead of repeating type
  
    print(myClass.publicVariable);
    myClass.publicMethod();
  }
  

• Declare with short name, should not allow to put type on left and right

  class UserInfo {
    var _status = "Active";
    
    var userName = "John Doe";
  
    void showInfo() {
      print(userName);  // Accessing public variable
      _logStatus();     // Call to private method
    }
  }
  
  void main() {
    var user = UserInfo();  // Using var and meaningful name
  
    print(user.userName);
    user.showInfo();
  }
  

• Avoid using generic type like user can put any value into that function.

  class UserInfo {
    String _status = "Active";
  
    String userName = "John Doe";
    
    // Public method to set user status with strict type
    void setStatus(String newStatus) {
      _status = newStatus;
    }
  }
  
  void main() {
    var user = UserInfo();
  
    user.setStatus("Inactive");
  }
  

• If it have default value from model try not to put with default value, but put it in model directly.

  class UserInfo {
    // Properties with no default values declared directly
    String userName;
    String _status;
  
    // Constructor with default values 
    UserInfo({String? userName, String? status})
        : userName = userName ?? "John Doe",  // Default value assigned here
          _status = status ?? "Active"; 
  }
  

• Try use existing function, do not use by manual, example 1. var.isEmpty()

  void main() {
    var user = UserInfo();
  
    // Not recommend
    if(user.userName != ''){
    
    }
    
    // Recommend
    print(user.userName.isEmpty()); // True  
  }

• Try to use type define by model not need to use like toString()

  void main() {
    // Creating a UserInfo without specifying the userName and status
    var user = UserInfo();
  
    // Not recommend
    print(user.userName.toString());  
  
    // Recommend
    print(user.userName); // Its already string type as define in Model
  }

Identifiers

Identifiers come in three flavors in Dart.

• UpperCamelCase names capitalize the first letter of each word, including the first.

• lowerCamelCase names capitalize the first letter of each word, except the first which is always lowercase, even if it's an acronym.

• lowercase_with_underscores names use only lowercase letters, even for acronyms, and separate words with _.

DO name types using UpperCamelCase

Classes, enum types, typedefs, and type parameters should capitalize the first letter of each word (including the first word), and use no separators.

good

class SliderMenu { ... }

class HttpRequest { ... }

typedef Predicate<T> = bool Function(T value);

DO name extensions using UpperCamelCase

Like types, extensions should capitalize the first letter of each word (including the first word), and use no separators.

extension MyFancyList<T> on List<T> { ... }

extension SmartIterable<T> on Iterable<T> { ... }

DO name packages, directories, and source files using lowercase_with_underscores

Some file systems are not case-sensitive, so many projects require filenames to be all lowercase. Using a separating character allows names to still be readable in that form. Using underscores as the separator ensures that the name is still a valid Dart identifier, which may be helpful if the language later supports symbolic imports.

good

my_package
└─ lib
   └─ file_system.dart
   └─ slider_menu.dart

bad

mypackage
└─ lib
   └─ file-system.dart
   └─ SliderMenu.dart

DO name import prefixes using lowercase_with_underscores

good

import 'dart:math' as math;
import 'package:angular_components/angular_components.dart' as angular_components;
import 'package:js/js.dart' as js;

bad

import 'dart:math' as Math;
import 'package:angular_components/angular_components.dart' as angularComponents;
import 'package:js/js.dart' as JS;

DO name other identifiers using lowerCamelCase

Class members, top-level definitions, variables, parameters, and named parameters should capitalize the first letter of each word except the first word, and use no separators.

good

var count = 3;

HttpRequest httpRequest;

void align(bool clearItems) {
  // ...
}

PREFER using lowerCamelCase for constant names

In new code, use lowerCamelCase for constant variables, including enum values.

good

const pi = 3.14;
const defaultTimeout = 1000;
final urlScheme = RegExp('^([a-z]+):');

class Dice {
  static final numberGenerator = Random();
}

bad

const PI = 3.14;
const DefaultTimeout = 1000;
final URL_SCHEME = RegExp('^([a-z]+):');

class Dice {
  static final NUMBER_GENERATOR = Random();
}