July Flutter Meetup - Developing a Flutter Package by Alexandre

Transcript

1. Developing a Flutter
   package
   Reusing code and widgets
   

   View Slide

2. Developing a Flutter package
   1
   2
   3
   4
   5
   6
   Creating a package
   Path vs Git dependencies
   Specifying subfolders and refs
   Exporting symbols
   Micro-libraries
   Github actions and secrets
   

   View Slide

3. Developing a Flutter package
   Reusing code and widgets
   Founder and CEO
   Art Plus Code Inc.
   Alexandre Quessy
   artpluscode.com
   artpluscode.com
   

   View Slide

4. Creating a package
   flutter create
   flutter create
   --template package
   --project-name my_widgets
   --org com.example
   --description "My widgets"
   dart create
   dart create
   --template package
   my_functions
   

   View Slide

5. dependencies:
   hello_package:
   path: ../hello_package/
   Your app can depend on a package in a local folder:
   Editing the pubspec.yaml
   dependencies:
   hello_package:
   git:
   url: https://github.com/artpluscodeinc/hello_package.git
   It can depend in a package in a remote Git repository:
   The official documentation: https://docs.flutter.dev/packages-and-plugins/using-packages#dependencies-on-unpublished-packages
   

   View Slide

6. dependencies:
   hello_package:
   git:
   url: git@github.com:artpluscodeinc/hello_package.git
   ref: main
   Can point to a specific branch or tag: (and use SSH instead of HTTPS)
   Editing the pubspec.yaml (cont'd)
   dependencies:
   hello_package:
   git:
   url: git@github.com:artpluscodeinc/many_packages.git
   path: packages/hello_package
   ref: 0.1.0
   Can specify the path to a subfolder: (and point to a tag)
   

   View Slide

7. dependency_overrides:
   hello_package:
   path: ../hello_package/
   Create another file called "pubpec_overrides.yaml"
   Overriding the pubspec.yaml
   

   View Slide

8. /// Our first library.
   library hello_package;
   export './src/counter_widget.dart' show CounterWidget;
   The code is lib/src/ is private, but can be exported from the files in lib/:
   Exporting symbols
   import 'package:hello_package/hello_package.dart' show CounterWidget;
   Then we can import it from our app:
   

   View Slide

9. Create multiple public files in lib/
   Micro-libraries
   Each file can be imported
   separately
   That's it!
   +
   +
   import 'package:hello_package/widgets.dart' show CounterWidget;
   import 'package:hello_package/add_numbers.dart' show add_numbers;
   

   View Slide

10. Testing your app
    

    View Slide

11. # This workflow installs the dependencies and runs the tests
    on:
    pull_request:
    name: Flutter Test
    jobs:
    build:
    name: Run flutter test
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@v3
    - uses: actions/setup-java@v1
    with:
    java-version: '12.x'
    - uses: subosito/flutter-action@v2
    with:
    channel: 'stable'
    - uses: webfactory/ssh-agent@v0.7.0
    with:
    ssh-private-key: |
    ${{ secrets.SSH_PRIVATE_KEY_FOR_THIS_APP_REPO}}
    - name: Get dependencies
    run: flutter pub get
    - name: Run tests
    run: flutter test --reporter expanded
    Use SSH keys if your library is
    private
    Setup your
    Github action
    Encrypted secrets: https://docs.github.com/en/actions/security-guides/encrypted-secrets
    Managing deploy keys: https://docs.github.com/en/authentication/connecting-to-github-with-ssh/managing-deploy-keys
    Create a SSH key pair
    Add the public key as a
    deploy secret for your app
    Add the private key as a secret for your package
    +
    +
    +
    

    View Slide

12. private: false
    To publish a package on pub.dev, first make it public:
    Publishing a public package
    dart pub publish --dry-run
    dart pub publish
    Log in to pub.dev with a Google account, and upload it:
    The official documentation: https://dart.dev/tools/pub/publishing
    Make sure its LICENSE is
    permissive (BSD-3)
    Edit the CHANGELOG.md
    +
    +
    Publishing is forever!
    You can then transfer it to a
    verified publisher, if you
    administer one.
    +
    +
    

    View Slide

13. Avenues for future investigations:
    Other considerations
    Use platform channels to write platform-specific code
    Use Git tags to specific some exact version of your library
    +
    +
    Mark deprecated symbols with the @Deprecated annotation
    +
    

    View Slide

14. THANK
    YOU! v
    

    View Slide