(en)Japanese ver is here.


This package is a practical Flutter (Dart) implementation of the Simple Widget Markup Language (SpWML).
SpWML allows for users to create statically flutter layout. It also reduces the amount of program code required and often speeds up compilation. Files output in SpWML have the extension .spwml.


Quick Start

Below is detailed documentation.
SpWML documentation

You can try how it works on the following sites.
SpWML Editor

Sample code

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

void main() {
  runApp(const MyApp());

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'SpWML Example',
      theme: ThemeData(
      home: const SpWMLSample(title: 'SpWML Example'),

class SpWMLSample extends StatefulWidget {
  const SpWMLSample({Key? key, required this.title}) : super(key: key);

  final String title;

  State<SpWMLSample> createState() => _SpWMLSampleState();

class _SpWMLSampleState extends State<SpWMLSample> {

  Widget _getSpWMLWidget(BuildContext context){
    return SpWMLBuilder("(h1)Example text").build(context);

  Widget build(BuildContext context) {
    return Scaffold(
            appBar: AppBar(
              title: Text(widget.title),
            body: _getSpWMLWidget(context)

Example of using inline elements

Please rewrite _getSpWMLWidget in Sample code as follows.

  Widget _getSpWMLWidget(BuildContext context){
    return SpWMLBuilder("(span)\n"

Cooperation with Widget

Please rewrite _getSpWMLWidget in Sample code as follows.

  Widget _getSpWMLWidget(BuildContext context) {
    SpWMLBuilder builder = SpWMLBuilder("(h1)Replace below this text.\n"
            "(block, id:1)");
                    onPressed: () {
                      ScaffoldMessenger.of(context).showSnackBar(const SnackBar(
                        content: Text("The button was pressed."),
                        duration: Duration(seconds: 3),
                    child: const Text("Flutter button")));

Customize basic design

Please rewrite _getSpWMLWidget in Sample code as follows.

  Widget _getSpWMLWidget(BuildContext context) {
  SpWMLFontStyle fontStyle1 = SpWMLFontStyle();
  SpWMLFontStyle fontStyle2 = SpWMLFontStyleMaterial();
  SpWMLFontStyle userCustomFontStyle = SpWMLFontStyle(h1Size: 48);
  return Column(
    children: [
      SpWMLBuilder("(h1)Example text", spWMLStyle: fontStyle1).build(context),
      SpWMLBuilder("(h1)Example text", spWMLStyle: fontStyle2).build(context),
      SpWMLBuilder("(h1)Example text", spWMLStyle: userCustomFontStyle)

The style can also be saved as a JSON file.
You can create a Map with toDict and restore it with fromDict.
Please consider if necessary.

  SpWMLFontStyle test = SpWMLFontStyle.fromDict(fontStyle1.toDict());

If you do not change the internal elements

It can be written more easily using the following wrapper widget. Please rewrite _getSpWMLWidget in Sample code as follows.

  Widget _getSpWMLWidget(BuildContext context) {
    return SpWML("(h1)Example text");


If you need paid support for any reason, please contact my company.
This package is developed by me personally, but may be supported via the company.
SimpleAppli Inc.

Format name

Simple Widget Markup Language



MIME Type (Temporary)


What this package is useful for

It is suitable for things that need to be created frequently and the layout is not so complicated, such as new information of apps. Even without updating the app itself, you can update the screen displayed to the user simply by changing the delivery file.

What this package is not useful

Not suitable for direct coding of complex app layouts.
However, it is possible to create a wire frame that is premised on replacement. Note that resource loading and parsing takes time.

About version control

The C part will be changed at the time of version upgrade.

  • Changes such as adding variables, structure change that cause problems when reading previous files.
    • C.X.X
  • Adding methods, etc.
    • X.C.X
  • Minor changes and bug fixes.
    • X.X.C


This software is released under the MIT License, see LICENSE file.

Copyright notice

The “Dart” name and “Flutter” name are trademarks of Google LLC.
*The developer of this package is not Google LLC.