16. Dart Package

                                       Dart Package

In Dart, packages are a way to organize and share libraries of code. They encapsulate reusable code components, making it easier to manage dependencies, share functionality across projects, and collaborate with other developers. Here’s an overview of Dart packages and how you can work with them:

What is a Dart Package?

A Dart package is a directory containing Dart code, along with a pubspec.yaml file that describes the package’s metadata and dependencies. Packages can include libraries, assets (like images or fonts), and other resources needed for a specific functionality or purpose.

my_dart_package/

  ├── lib/

  │   └── my_dart_package.dart

  ├── pubspec.yaml

my_dart_project/

  ├── bin/

  │   └── main.dart

  ├── pubspec.yaml

Creating a Dart Package and Using It in Another Dart Project

Step 1: Create a Dart Package

Create Directory Structure: First, create a directory for your package. Let’s call it my_dart_package.

mkdir my_dart_package

cd my_dart_package

mkdir lib

Create pubspec.yaml File: Create a pubspec.yaml file in the root of my_dart_package directory with the following content:

ame: my_dart_package
version: 1.0.0
description: A sample Dart package
dependencies:
  flutter:
    sdk: flutter


environment:
  sdk: '^3.3.0'

Add Dart Code: Create a Dart file in the lib directory. Let’s name it my_dart_package.dart and add some simple code.
lib/my_dart_package.dart:

library my_dart_package;
String greet(String name) => 'Hello, $name!';

Step 2: Use the Package in Another Dart Project

Create a New Dart Project: Create a new Dart project where you will use the my_dart_package. Let’s call this project my_dart_project.

mkdir my_dart_project

cd my_dart_project

dart create .

Add Dependency: In the pubspec.yaml of your my_dart_project, add a dependency to my_dart_package. If the package is local, you can specify the path to it.
my_dart_project/pubspec.yaml:

name: my_dart_project
description: A sample Dart project
version: 1.0.0


environment:
  sdk: ">=2.12.0 <3.0.0"


dependencies:
  my_dart_package:
    path: ../my_dart_package

Install Dependencies: Run pub get to install the dependencies.

dart pub get

Import and Use the Package: Now, you can import and use my_dart_package in your Dart project.

bin/main.dart:

import 'package:my_dart_package/my_dart_package.dart';
// import 'package:';


void main() {
  String message = greet('World');
  print(message); // Output: Hello, World!
}

Step 4: Run Your Dart Project

To run your Dart project and see the output:

Navigate to your project directory.

cd my_dart_project

Run the project:

dart run bin/main.dart

You should see the output:

Hello, World!