A Flutter widget to use Echarts in a reactive way.

Features

Reactive Updating

The most exciting feature of Flutter widgets and React components is that the view could update reactively to the change of data. Thanks to Echarts’ data driving architecture, flutter_echarts implemented a reactive way to connect chart with data. The chart will automatically re-render when the data in the option property changes.

Two Way Communication

The onMessage and extraScript properties provide a way to set event communication both from flutter to JavaScript or in controversy.

Configurable Extensions

Echarts has a lot of extensions . the extensions property allows you to inject the extension scripts as raw strings. In this way, you can copy these scripts to your source code, without concerning about the confusing assets dirs.

Installing

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

dependencies:
  flutter_echarts: #latest version

Now in your Dart code, you can use:

import 'package:flutter_echarts/flutter_echarts.dart';

Details see pub.dev .

Usage

The flutter_echarts itself is very simple to use, just like a common statelessWidget:

Details about the option is in the Echarts docs or Echarts examples

Container(
  child: Echarts(
  option: '''
    {
      xAxis: {
        type: 'category',
        data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
      },
      yAxis: {
        type: 'value'
      },
      series: [{
        data: [820, 932, 901, 934, 1290, 1330, 1320],
        type: 'line'
      }]
    }
  ''',
  ),
  width: 300,
  height: 250,
)

For an ios app, you need to add this entry to your Info.plist’ <dic> tag:

<key>io.flutter.embedded_views_preview</key>
<string>YES</string>

A full example is here: flutter_echarts_example .

Widget Properties

option

String

( required )

The JavaScript Echarts Option for the chart as a string. The echarts is mainly configured by this property. You could use jsonEncode() function in dart:convert to convert data in Dart object form:

source: ${jsonEncode(_data1)},

Because JavaScript don’t have ''' , you can use this operator to reduce some escape operators for quotas:

Echarts(
  option: '''

    // option string

  ''',
),

extraScript

String

The JavaScript which will execute after the Echarts.init() and before any chart.setOption() . The widget has build a javascriptChennel named Messager, so you could use this identifier to send message from JavaScript to Flutter:

extraScript: '''
  chart.on('click', (params) => {
    if(params.componentType === 'series') {
      Messager.postMessage('anything');
    }
  });
''',

onMessage

void Function(String)

Function to handle the message sent by Messager.postMessage() in extraScript .

extensions

List\<String>

List of strings that coyied from Echarts extensions, such as themes, components, WebGL, languages, etc. You can download them here . Insert them as raw strings:

const liquidPlugin = r'''

  // copy from liquid.min.js

''';

theme

String

You can download built-in themes here or build own custom themes with this tool . Copy the theme script into the extensions param and register the theme name with this param.

captureAllGestures

bool

( default: false )

Whether the chart captures all gestures. Setting it ture is usefull when handling 3D rotation and data zoom bars. Note that will prevent containers like ListViews to act to gestures on the charts.