docs(rest_api): add example for REST Api handling

[BenAuerDev]

Related Issues

related to: #3932

Add example for handling REST API with riverpod.

• Fetch users (GET)
• Create user (POST)
• Loading/error states
• Pull-to-refresh
• Testing

Please let me know when there is anything to improve :) I'll do it asap :muscle: :rocket:

Checklist

Before you create this PR confirm that it meets all requirements listed below by checking the relevant checkboxes ([x]).

• [ ] I have updated the CHANGELOG.md of the relevant packages. Changelog files must be edited under the form:

  ## Unreleased fix/major/minor
  
  - Description of your change. (thanks to @yourGithubId)
  

• [ ] If this contains new features or behavior changes, I have updated the documentation to match those changes.

Summary by CodeRabbit

• New Features

  • Added a REST API example project using Riverpod for state management.
  • Implemented user management functionality with CRUD operations.
  • Created screens for listing and adding users.
  • Introduced a metadata file for project tracking and configuration.

• Documentation

  • Added project README with detailed explanation of functionality.
  • Created analysis configuration for code quality.

• Testing

  • Implemented unit tests for repository and state management.
  • Added widget tests for UI components and error scenarios.

[coderabbitai[bot]]

Walkthrough

This pull request introduces a comprehensive example of a REST API Flutter application using Riverpod for state management and Dio for HTTP requests. The project includes a complete implementation with a user management interface, featuring user listing, adding new users, error handling, and a full test suite. The example demonstrates modern Dart and Flutter development practices, including asynchronous state management, form validation, and comprehensive testing strategies.

Changes

File	Change Summary
examples/rest_api/.metadata	New project metadata file tracking Flutter SDK version and project configuration
examples/rest_api/README.md	New documentation explaining the REST API example's functionality and structure
examples/rest_api/analysis_options.yaml	Added linting and static analysis configuration for code quality
examples/rest_api/lib/main.dart	Implemented core application logic with User model, repository, state management, and UI components
examples/rest_api/pubspec.yaml	Defined project dependencies, including Riverpod, Dio, and testing libraries
examples/rest_api/test/user_test.dart	Added unit tests for UserRepository and UsersNotifier
examples/rest_api/test/user_test.mocks.dart	Generated mock classes for Dio testing
examples/rest_api/test/widget_test.dart	Implemented widget tests for user list and add user screens

Sequence Diagram

sequenceDiagram
    participant UI as UserListScreen
    participant State as UsersNotifier
    participant Repo as UserRepository
    participant API as REST API

    UI->>State: Fetch Users
    State->>Repo: fetchUsers()
    Repo->>API: GET /users
    API-->>Repo: Return User List
    Repo-->>State: Update Users
    State-->>UI: Render User List

    UI->>State: Add New User
    State->>Repo: createUser(newUser)
    Repo->>API: POST /users
    API-->>Repo: Confirm User Creation
    Repo-->>State: Update State
    State-->>UI: Refresh User List

Poem

🐰 A Rabbit's REST API Tale 🌐

In Flutter's realm, with Riverpod's might,
Users dance through requests so bright.
Dio fetches, state transforms with glee,
A code adventure, wild and free!
Hop, hop, API magic unfurled! 🚀

---

Thank you for using CodeRabbit. We offer it for free to the OSS community and would appreciate your support in helping us grow. If you find it useful, would you consider giving us a shout-out on your favorite social media?

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

🪧 Tips

Chat

There are 3 ways to chat with CodeRabbit:

• Review comments: Directly reply to a review comment made by CodeRabbit. Example:
  • I pushed a fix in commit <commit_id>, please review it.
  • Generate unit testing code for this file.
  • Open a follow-up GitHub issue for this discussion.
• Files and specific lines of code (under the "Files changed" tab): Tag @coderabbitai in a new review comment at the desired location with your query. Examples:
  • @coderabbitai generate unit testing code for this file.
  • @coderabbitai modularize this function.
• PR comments: Tag @coderabbitai in a new PR comment to ask questions about the PR branch. For the best results, please provide a very specific query, as very limited context is provided in this mode. Examples:
  • @coderabbitai gather interesting stats about this repository and render them as a table. Additionally, render a pie chart showing the language distribution in the codebase.
  • @coderabbitai read src/utils.ts and generate unit testing code.
  • @coderabbitai read the files in the src/scheduler package and generate a class diagram using mermaid and a README in the markdown format.
  • @coderabbitai help me debug CodeRabbit configuration file.

Note: Be mindful of the bot's finite context window. It's strongly recommended to break down tasks such as reading entire modules into smaller chunks. For a focused discussion, use review comments to chat about specific files and their changes, instead of using the PR comments.

CodeRabbit Commands (Invoked using PR comments)

• @coderabbitai pause to pause the reviews on a PR.
• @coderabbitai resume to resume the paused reviews.
• @coderabbitai review to trigger an incremental review. This is useful when automatic reviews are disabled for the repository.
• @coderabbitai full review to do a full review from scratch and review all the files again.
• @coderabbitai summary to regenerate the summary of the PR.
• @coderabbitai generate docstrings to generate docstrings for this PR. (Beta)
• @coderabbitai resolve resolve all the CodeRabbit review comments.
• @coderabbitai configuration to show the current CodeRabbit configuration for the repository.
• @coderabbitai help to get help.

Other keywords and placeholders

• Add @coderabbitai ignore anywhere in the PR description to prevent this PR from being reviewed.
• Add @coderabbitai summary to generate the high-level summary at a specific location in the PR description.
• Add @coderabbitai anywhere in the PR title to generate the title automatically.

CodeRabbit Configuration File (.coderabbit.yaml)

• You can programmatically configure CodeRabbit by adding a .coderabbit.yaml file to the root of your repository.
• Please see the configuration documentation for more information.
• If your editor has YAML language server enabled, you can add the path at the top of this file to enable auto-completion and validation: # yaml-language-server: $schema=https://coderabbit.ai/integrations/schema.v2.json

Documentation and Community

• Visit our Documentation for detailed information on how to use CodeRabbit.
• Join our Discord Community to get help, request features, and share feedback.
• Follow us on X/Twitter for updates and announcements.

[BenAuerDev]

The changes proposed by Code Rabbit are really cool, but aren't some of them a bit too advanced for a beginner example?

Also the failing code-generation check I don't fully understand yet. But I'll investigate it further asap :)

[BenAuerDev]

@rrousselGit it seems that the workflow failed due to a problem with the dart file. Can you rerun the jobs?

Run flutter pub get
  flutter pub get
  shell: /usr/bin/bash -e {0}
  env:
    FLUTTER_ROOT: /opt/hostedtoolcache/flutter/master-master-x64
    PUB_CACHE: /home/runner/.pub-cache
Downloading Linux x64 Dart SDK from Flutter engine cdce7658473f4eafbf9d[2](https://github.com/rrousselGit/riverpod/actions/runs/13287118192/job/37098382308#step:6:2)83affd3de6d73fd0d97...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed

  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100   255  100   255    0     0   28[3](https://github.com/rrousselGit/riverpod/actions/runs/13287118192/job/37098382308#step:6:3)0      0 --:--:-- --:--:-- --:--:--  2833
[/opt/hostedtoolcache/flutter/master-master-x6[4](https://github.com/rrousselGit/riverpod/actions/runs/13287118192/job/37098382308#step:6:4)/bin/cache/dart-sdk-linux-x64.zip]
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of /opt/hostedtoolcache/flutter/master-master-x[6](https://github.com/rrousselGit/riverpod/actions/runs/13287118192/job/37098382308#step:6:6)4/bin/cache/dart-sdk-linux-x64.zip or
        /opt/hostedtoolcache/flutter/master-master-x64/bin/cache/dart-sdk-linux-x64.zip.zip, and cannot find /opt/hostedtoolcache/flutter/master-master-x64/bin/cache/dart-sdk-linux-x64.zip.ZIP, period.

It appears that the downloaded file is corrupt; please try again.
If this problem persists, please report the problem at:
  https://github.com/flutter/flutter/issues/new?template=1_activation.yml