scoped_model 0.2.0

  • README.md
  • CHANGELOG.md
  • Example
  • Installing
  • Versions
  • 96

scoped_model

Build Status codecov

A set of utilities that allow you to easily pass a data Model from a parent Widget down to it's descendants. In addition, it also re-renders all of the children who use the model when the model is updated.

Besides a couple of tests and a bit of documentation, this is not my work / idea. It's a simple extraction of the Model classes from Fuchsia's core Widgets, presented as a standalone Flutter Plugin for independent use so we can evaluate this architecture pattern more easily as a community.

Usage

Let's demo the basic usage with the all-time favorite: A counter example!

// Start by creating a class that holds some view the app's state. In
// our example, we'll have a simple counter that starts at 0 can be 
// incremented.
//
// Note: It must extend from Model.  
class CounterModel extends Model {
  int _counter = 0;

  int get counter => _counter;

  void increment() {
    // First, increment the counter
    _counter++;
    
    // Then notify all the listeners.
    notifyListeners();
  }
}

// Create our App, which will provide the `CounterModel` to 
// all children that require it! 
class CounterApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // First, create a `ScopedModel` widget. This will provide 
    // the `model` to the children that request it. 
    return new ScopedModel<CounterModel>(
      model: new CounterModel(),
      child: new Column(children: [
        // Create a ScopedModelDescendant. This widget will get the
        // CounterModel from the nearest ScopedModel<CounterModel>. 
        // It will hand that model to our builder method, and rebuild 
        // any time the CounterModel changes (i.e. after we 
        // `notifyListeners` in the Model). 
        new ScopedModelDescendant<CounterModel>(
                builder: (context, child, model) => new Text(
                    model.counter.toString()),
              ),
        new Text("Another widget that doesn't depend on the CounterModel")
      ])
    );
  }
}

Contributors

Changelog

0.2.0

  • Thanks to @passsy for the contributions!
  • Model cannot be null
  • Model now implements Listenable
  • Improve Docs
  • Improve tests

0.1.1

  • Move to github

0.1.0

  • Initial version

example/lib/main.dart

import 'package:flutter/material.dart';
import 'package:scoped_model/scoped_model.dart';

void main() {
  runApp(new MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // At the top level of our app, we'll, create a ScopedModel Widget. This
    // will provide the CounterModel to all children in the app that request it
    // using a ScopedModelDescendant.
    return new ScopedModel<CounterModel>(
      model: new CounterModel(),
      child: new MaterialApp(
        title: 'Flutter Demo',
        theme: new ThemeData(
          primarySwatch: Colors.green,
        ),
        home: new CounterHome('Scoped Model Demo'),
      ),
    );
  }
}

// Start by creating a class that has a counter and a method to increment it.
//
// Note: It must extend from Model.
class CounterModel extends Model {
  int _counter = 0;

  int get counter => _counter;

  void increment() {
    // First, increment the counter
    _counter++;

    // Then notify all the listeners.
    notifyListeners();
  }
}

class CounterHome extends StatelessWidget {
  final String title;

  CounterHome(this.title);

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: new AppBar(
        title: new Text(title),
      ),
      body: new Center(
        child: new Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            new Text(
              'You have pushed the button this many times:',
            ),
            // Create a ScopedModelDescendant. This widget will get the
            // CounterModel from the nearest parent ScopedModel<CounterModel>.
            // It will hand that CounterModel to our builder method, and
            // rebuild any time the CounterModel changes (i.e. after we
            // `notifyListeners` in the Model).
            new ScopedModelDescendant<CounterModel>(
              builder: (context, child, model) => new Text(
                  model.counter.toString(),
                  style: Theme.of(context).textTheme.display1),
            ),
          ],
        ),
      ),
      // Use the ScopedModelDescendant again in order to use the increment
      // method from the CounterModel
      floatingActionButton: new ScopedModelDescendant<CounterModel>(
        builder: (context, child, model) => new FloatingActionButton(
              onPressed: model.increment,
              tooltip: 'Increment',
              child: new Icon(Icons.add),
            ),
      ),
    );
  }
}

Use this package as a library

1. Depend on it

Add this to your package's pubspec.yaml file:


dependencies:
  scoped_model: "^0.2.0"

2. Install it

You can install packages from the command line:

with Flutter:


$ flutter packages get

Alternatively, your editor might support flutter packages get. Check the docs for your editor to learn more.

3. Import it

Now in your Dart code, you can use:


      import 'package:scoped_model/scoped_model.dart';
  
Version Uploaded Documentation Archive
0.2.0 Jan 4, 2018 Go to the documentation of scoped_model 0.2.0 Download scoped_model 0.2.0 archive
0.1.1 Nov 25, 2017 Go to the documentation of scoped_model 0.1.1 Download scoped_model 0.1.1 archive
0.1.0 Aug 17, 2017 Go to the documentation of scoped_model 0.1.0 Download scoped_model 0.1.0 archive

Analysis

We analyzed this package on Jun 12, 2018, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.0.0-dev.60.0
  • pana: 0.11.3
  • Flutter: 0.5.2

Scores

Popularity:
Describes how popular the package is relative to other packages. [more]
92 / 100
Health:
Code health derived from static analysis. [more]
99 / 100
Maintenance:
Reflects how tidy and up-to-date the package is. [more]
100 / 100
Overall score:
Weighted score of the above. [more]
96
Learn more about scoring.

Platforms

Detected platforms: Flutter

References Flutter, and has no conflicting libraries.

Suggestions

  • Package is pre-v1 release.

    While there is nothing inherently wrong with versions of 0.*.*, it usually means that the author is still experimenting with the general direction API.

  • Fix analysis and formatting issues.

    Analysis or formatting checks reported 2 hints.

    Run flutter format to format lib/generated/i18n.dart.

Dependencies

Package Constraint Resolved Available
Direct dependencies
flutter 0.0.0
Transitive dependencies
collection 1.14.6 1.14.10
meta 1.1.5
sky_engine 0.0.99
typed_data 1.1.5
vector_math 2.0.6 2.0.7
Dev dependencies
flutter_test