Upgrade & Secure Your Future with DevOps, SRE, DevSecOps, MLOps!
We spend hours scrolling social media and waste money on things we forget, but won’t spend 30 minutes a day earning certifications that can change our lives.
Master in DevOps, SRE, DevSecOps & MLOps by DevOps School!
Learn from Guru Rajesh Kumar and double your salary in just one year.
Packages are used in the Dart ecosystem to handle common software like libraries and tools. The pub package manager is used to obtain Dart packages. You can load packages from the local file system, remote locations, such as Git repositories, or via the pub.dev website, which lists publicly accessible packages. Pub maintains version dependencies, enabling you to obtain package versions that are compatible with one another and with the SDK version, regardless of where your packages originate.
The majority of Dart-savvy IDEs include support for utilising pub, including package creation, download, updating, and publication. You can also use the command line programme dart pub.
A pubspec file is the bare minimum that constitutes a Dart package. Some package-related metadata can be found in the pubspec. Moreover, a package can
To use a package, do the following:
- Create a pubspec (a file named pubspec.yaml that lists package dependencies and includes other metadata, such as a version number).
- Use dart pub get to retrieve your package’s dependencies.
- If your Dart code depends on a library in the package, import the library.
Creating a pubspec
The top directory of your application contains a file with the name pubspec.yaml that contains the pubspec. The simplest pubspec possible merely includes the package name:
name: my_app
Code language: HTTP (http)
Here is an illustration of a pubspec that lists two packages (js and intl) that are hosted on the pub.dev website as dependencies:
name: my_app
dependencies:
js: ^0.6.0
intl: ^0.17.0
Code language: CSS (css)
Run the dart pub add command to update the pubspec.yaml file without manually modifying it. The sample that follows includes a reliance on vector_math.
$ dart pub add vector_math
Resolving dependencies...
+ vector_math 2.1.3
Downloading vector_math 2.1.3...
Changed 1 dependency!
Getting packages
Once you have a pubspec, you can run dart pub get from the top directory of your application:
$cd <path-to-my_app>
$dart pub get
Code language: PHP (php)
Importing libraries from packages
To import libraries found in packages, use the package: prefix:
import 'package:js/js.dart' as js;
import 'package:intl/intl.dart';
Code language: JavaScript (javascript)
Everything after package: is retrieved by the Dart runtime from your app’s package_config.json file.
This style can also be used to import libraries from your own package. Let’s assume that the transmogrify package looks like this:
transmogrify/
lib/
transmogrify.dart
parser.dart
test/
parser/
parser_test.dart
He parser_test.dart file can import parser.dart like this:
import 'package:transmogrify/parser.dart';
Code language: JavaScript (javascript)
Upgrading a dependency
$ dart pub upgrade
The dart pub upgrade command tells pub to regenerate the lockfile, using the newest available versions of your package’s dependencies. If you want to upgrade only one dependency, you can specify the package to upgrade:
$dart pub upgrade transmogrify
Code language: PHP (php)