mariposa 1.0.0

  • Example
  • Installing
  • Versions
  • new45


Stupid-simple, low-level Web application library built with Incremental DOM and html_builder. Somewhat comparable to React.

Mariposa offers no state management; this is by design. Handling state should be handled via dart:async, Redux, or some other mechanism. Calling for a re-render is not memory-intensive, thanks to Incremental DOM.

Thanks to libraries like zen and html_builder/elements.dart, it is possible to cleanly build HTML AST's with a Dart DSL that looks exactly like an HTML AST.


The most simple example:

import 'dart:html' hide Node;
import 'package:html_builder/elements.dart';
import 'package:html_builder/html_builder.dart';
import 'package:mariposa/dom.dart' as mariposa_dom;

Node greeting({String message}) => b(c: [text(message)]);

void main() {
    () => greeting(message: 'Hello!'),

This is a super-small example of an application without state. See web/main.dart for an example of an application with state. Complex applications should consider dart:async, Redux, Flux, or some similar state management architecture to create manageable applications.


Note: Not the same as Flutter widgets.

In real-world applications, oftentimes one will need to interact with the state of the DOM, or whatever tree is being rendered.

For this, create a Widget. Not only can widgets be rendered like normal nodes, but upon rendering, their afterRender method is called. Right before destruction, beforeDestroy is invoked.

Both methods are passed an AbstractElement, which prevents a platform-agnostic way to handle events, perform query selectors, and other things. Abstract elements always provide a handle to the nativeElement.

This makes it possible to manage the state of a specific node in the tree, among other things.

import 'dart:io';
import 'package:html_builder/html_builder.dart';
import 'package:html_builder/elements.dart';
import 'package:mariposa/dom.dart' as mariposa;

Server-side Rendering

It's easy; in fact, server-side rendering is Mariposa's bread-and-butter. DOM support was added long after string rendering:

import 'dart:io';
import 'package:html_builder/html_builder.dart';
import 'package:html_builder/elements.dart';
import 'package:mariposa/string.dart' as mariposa;

main() async {
  var server = await HttpServer.bind(InternetAddress.loopbackIPv4, 3000);
  print('Listening at http://${server.address.address}:${server.port}');

  await for (var request in server) {
    var html = mariposa.render(myApp());
      ..headers.contentType = ContentType.HTML

Node myApp() {
  return html(c: [
    head(c: [
        name: 'viewport',
        content: 'width=device-width, initial-scale=1',
      title(c: [
        text('Hello, Mariposa!'),
    body(c: [
      h1(c: [
        text('Hello, Mariposa!'),
      i(c: [
        text('Server-side rendering is easy!'),


import 'dart:html' hide Node;
import 'package:html_builder/elements.dart';
import 'package:html_builder/html_builder.dart';
import 'package:mariposa/dom.dart' as mariposa_dom;

Node greeting({String message}) => b(c: [text(message)]);

void main() {
    () => greeting(message: 'Hello!'),

Use this package as a library

1. Depend on it

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

  mariposa: "^1.0.0"

2. Install it

You can install packages from the command line:

with pub:

$ pub get

with Flutter:

$ flutter packages get

Alternatively, your editor might support pub get or 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:mariposa/mariposa.dart';
Version Uploaded Documentation Archive
1.0.0 Jun 2, 2018 Go to the documentation of mariposa 1.0.0 Download mariposa 1.0.0 archive


We analyzed this package on Jun 19, 2018, and provided a score, details, and suggestions below. Analysis was completed with status completed using:

  • Dart: 2.0.0-dev.63.0
  • pana: 0.11.3


Describes how popular the package is relative to other packages. [more]
0 / 100
Code health derived from static analysis. [more]
98 / 100
Reflects how tidy and up-to-date the package is. [more]
80 / 100
Overall score:
Weighted score of the above. [more]
Learn more about scoring.


Detected platforms: Flutter, web, other

No platform restriction found in primary library package:mariposa/mariposa.dart.


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  • Fix analysis and formatting issues.

    Analysis or formatting checks reported 4 hints.

    Run dartfmt to format lib/dom.dart.

    Run dartfmt to format lib/mariposa.dart.

    Similar analysis of the following files failed:

    • lib/src/abstract_element.dart (hint)
    • lib/string.dart (hint)


Package Constraint Resolved Available
Direct dependencies
Dart SDK >=2.0.0-dev <3.0.0
html_builder ^1.0.0 1.0.2
js ^0.6.1 0.6.1
zen ^1.0.0 1.0.0
Transitive dependencies
args 1.4.3
charcode 1.1.1
csslib 0.14.4
logging 0.11.3+1
path 1.6.1
source_span 1.4.0
Dev dependencies
build_runner ^0.8.0
build_web_compilers ^0.4.0