Flutter packages advance concepts

Types of Packages

Dart Packages can be classed based on their usefulness because they are essentially a tiny collection of related functionality.

1. Dart Package 
   A path package, for example, is a general package created in the Dart programming language. This package can be used in either a web or mobile environment. It also depends on the Flutter framework, such as the fluro package, because it provides some Flutter-specific features.
2. Plugin Package
   It's a specific Dart package that offers a Dart-based API that relies on the Flutter framework. It can be used in conjunction with a platform-specific implementation for an underlying platform like Android (using Java or Kotlin) or iOS (using Objective C or Swift). The battery and image picker plugin package is an example of this package.
3. Flutter Plugin
   Dart code that relies on the Flutter framework and the underlying platform code (Android SDK or iOS SDK). For instance, a camera is a plugin that allows you to communicate with your device's camera. Getting access to the camera is dependent on the Flutter framework as well as the underlying foundation.

Dart Packages v/s Plugin Packages

There are two sorts of packages in Flutter.
A pure Dart package, such as a new Widget or a set of Dart classes, is commonly referred to simply as a 'package.'
The second type of package makes platform-specific functionality more accessible. The "battery" package, for example, allows you to check battery information. This requires access to the platform, which the package takes care of. Plugins are the term for these types of software.

Developing a Flutter Package 

In terms of development, a Flutter plugin or package is equivalent to a Dart application or package. However, there are some exceptions, such as when a plugin uses the system API of a platform, such as Android or iOS, to gain the required functionality. Let's take a step-by-step look at how to make a package in Flutter.

Step 1: To begin, open Android Studio and select File > Select a New Flutter Project from the File menu. On your screen, a dialogue box will display.

Step 2:Select the Flutter option in this dialogue box, then enter the location of the Flutter SDK as indicated in the image below and click Next.

Step 3: Enter all of the specifics of your package in the following dialogue box, including the project name, location, and description. After you've completed all of the fields, click Finish.

Step 4: Finally, your project will be finished. Open the flutter custom package.dart file and remove the default code that was created when the project was established. Then type in the code below. This code snippet builds a package for an alert box.

library flutter_codingninjas;  
  
import 'package:flutter/material.dart';  
  
class CustomPackageAlertBox {  
  static Future showCustomAlertBox({  
    @required BuildContext context,  
    @required Widget willDisplayWidget,  
  }) {  
    assert(context != null, "If context is null!!");  
    assert(willDisplayWidget != null, "If willDisplayWidget is null!!");  
    return showDialog(  
        context: context,  
        builder: (context) {  
          return AlertDialog(  
            shape: RoundedRectangleBorder(  
              borderRadius: BorderRadius.all(Radius.circular(20)),  
            ),  
            content: Column(  
              mainAxisSize: MainAxisSize.min,  
              children: <Widget>[  
                willDisplayWidget,  
                MaterialButton(  
                  color: Colors.white70,  
                  child: Text('Close Alert'),  
                  onPressed: () {  
                    Navigator.of(context).pop();  
                  },  
                )  
              ],  
            ),  
            elevation: 12,  
          );  
        });  
  }  
}  

It's now time to put your freshly created package to the test. To try the package, create a new project. To begin, open pubspec.yaml and put the following code into the dependant section.

dependencies:   
   flutter:   
      sdk: flutter   
   flutter_custom_package:   
      path: ../  

When you add a custom package to the pubspec.yaml file, Android Studio warns you that you need to update it. To update the file, click the Get dependencies button and make sure you have an online connection while doing so. The package is automatically downloaded from the internet and configured for your application by Android Studio. This package is now available for use. You can import the package as follows in the dart file:

Publishing a Flutter Package

You can publish a package in the pub. dev directory when it has been successfully implemented so that anyone can use it in the project.
Before publishing the package, double-check that the content of pubspec.yaml, README.md, and CHANGELOG.md files is complete and correct.
Then run the following command in a terminal window to evaluate each phase of the package.

$ flutter pub publish --dry-run  

Finally, to publish the package, type the following command.

$ flutter pub publish  

Top Open Source Packages

Open-source packages are extremely important in software development, especially for creating Flutter apps. Pub. dev has a growing ecosystem of over 24,000 packages to let you extend the functionality of your Flutter app and leverage community-created solutions.

• alchemist
• collection
• coverage 
• cloud_firestore 
• equatable 
  and many more. 

FAQs

What are Flutter packages and what are the different types of packages?

A package is a namespace that contains a group of related classes, interfaces, and sub-packages. Packages can be compared to different folders on our computers, where we store videos, photos, software, and so on.

In Flutter, what is the difference between a plugin and a package?

A "package" is a collection of Dart code. Dart and Native code (kotlin/js/swift/...) are combined in a "plugin." If a package wishes to, it can use plugins. It will still be considered a package.

In Flutter, which file is used to install packages?

There are other methods for installing a package, but the most frequent and straightforward one is to include it in your project's pubspec file. Simply copy the dependencies code and paste it into your project's pubspec. ymal file.

What happened to all the flutter packages?

On Mac and Linux, the system package cache is located in the pub-cache subfolder of your home directory, or in percent APPDATA percent PubCache (on Windows; the location might vary depending on the Windows version).

How can I delete a flutter package?

All you have to do now is remove the plugin from the pubspec.yaml file. Run flutter packages get after that. When you rebuild your project, Flutter will automatically remove the native plugin code.

Conclusion

To summarize the above article we have learned about the packages in Flutter, and the types of packages in Flutter. Also, we have learned how we can create and publish flutter packages. Hope you learned something. But the knowledge never stops, So to learn more you can visit our website for more articles. 

Check out our articles on Flutter Row and Column, Flutter Lists and Flutter Checkbox 

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