EventSubscriber

A Flutter widget that rebuilds for every new Event.

The EventSubscriber widget will be notified and will rebuild when one or more Event occurs, allowing some changing aspect of an observed object to be displayed in your Flutter user interface.

Note: run the included Example project to see a working example.

See CHANGELOG.md to see what has changed in this version.

Contents

• Usage
• See also
• Dependencies
• Example
• Requesting Features and Reporting Bugs

Usage

The Flutter EventSubscriber Widget requires that you specify one or more Events, along with a builder function that returns a child Widget.

// example
EventSubscriber(
  events: [myCount.valueChanged],  // a List of 1 or more Events
  builder: (context, status, args) => Text('${myCount.value}'),
),

See Also

Event - A Dart package that broadcasts events to interested subscribers.

Dependencies

• Flutter - This package has a dependency on the Flutter framework.
• Event - Supports the creation of lightweight custom Dart Events, that allow interested subscribers to be notified that something has happened. Provides a notification mechanism across independent packages/layers/modules. Dependent on Dart only.

Example

See the example folder for a more detailed example.

import 'package:flutter/material.dart';
import 'package:event/event.dart';
import 'package:eventsubscriber/eventsubscriber.dart';

// An example domain model of a simple Counter
// Normally in its own module/package
// Included here inline for illustration purposes
class Counter {
  int value = 0;
  var valueChanged = Event(); // declare Event

  void increment() {
    value++;
    // broadcast that the value has changed
    valueChanged.broadcast();
  }
}

//////////////////////

// Create the domain model
var myCounter = Counter();

// Flutter application
// The Counter value will increment when the button is pressed.
// The updated value will be automatically updated in the UI.
void main() => runApp(
      MaterialApp(
        home: Column(
          children: <Widget>[
            // Subscribe to the 'valueChanged' domain event
            EventSubscriber(
              events: [myCounter.valueChanged],
              builder: (context, status, args) {
                return Text(myCount.value.toString());
              },
            ),
            FlatButton(
              child: Text('Increment'),
              // Increment the domain value
              onPressed: () => myCounter.increment(),
            )
          ],
        ),
      ),
    );

Requesting Features and Reporting Bugs

Please enter feature requests and report bugs at the issue tracker.