flutter_widget_from_html 0.5.2-rc.2021011801

Flutter package for widget tree building from html that supports hyperlink, image, nested list, etc.

Flutter Widget from HTML

A Flutter package for building Flutter widget tree from HTML with support for IFRAME, VIDEO and 70+ other tags.

Live demo

Getting Started

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

dependencies:
  flutter_widget_from_html: ^0.5.2

Usage

Then you have to import the package with:

import 'package:flutter_widget_from_html/flutter_widget_from_html.dart';

And use HtmlWidget where appropriate:

HtmlWidget(
  // the first parameter (`html`) is required
  '''
  <h3>Heading</h3>
  <p>
    A paragraph with <strong>strong</strong>, <em>emphasized</em>
    and <span style="color: red">colored</span> text.
  </p>
  <!-- anything goes here -->
  ''',

  // all other parameters are optional, a few notable params:

  // specify custom styling for an element
  // see supported inline styling below
  customStylesBuilder: (element) {
    if (element.classes.contains('foo')) {
      return {'color': 'red'};
    }

    return null;
  },

  // render a custom widget
  customWidgetBuilder: (element) {
    if (element.attributes['foo'] == 'bar') {
      return FooBarWidget();
    }

    return null;
  },

  // set the default styling for text
  textStyle: TextStyle(fontSize: 14),

  // turn on `webView` if you need IFRAME support
  webView: true,
),

Features

HTML tags

Below tags are the ones that have special meaning / styling, all other tags will be parsed as text. Compare between Flutter rendering and browser's.

• A: underline, theme accent color
  • Scroll to anchor
  • Launch URL via url_launcher with base URL resolver
• H1/H2/H3/H4/H5/H6
• IFRAME via webview_flutter
• IMG with support for asset (asset://), data uri and network image via cached_network_image. Additional .svg file support via flutter_svg.
• LI/OL/UL with support for:
  • Attributes: type, start, reversed
  • Inline style list-style-type values: lower-alpha, upper-alpha, lower-latin, upper-latin, circle, decimal, disc, lower-roman, upper-roman, square
• TABLE/CAPTION/THEAD/TBODY/TFOOT/TR/TD/TH with support for:
  • TABLE attributes border, cellpadding, cellspacing
  • TD/TH attributes colspan, rowspan, valign
• SVG via flutter_svg
• VIDEO via chewie
• ABBR, ACRONYM, ADDRESS, ARTICLE, ASIDE, B, BIG, BLOCKQUOTE, BR, CENTER, CITE, CODE, DD, DEL, DFN, DIV, DL, DT, EM, FIGCAPTION, FIGURE, FONT, FOOTER, HEADER, HR, I, INS, KBD, MAIN, NAV, P, PRE, Q, RP, RT, RUBY, S, SAMP, SECTION, STRIKE, STRONG, SUB, SUP, TT, U, VAR
• Everything with screenshot: https://html-widget-demo.now.sh/supported/tags.html

These tags and their contents will be ignored:

• SCRIPT
• STYLE

Attributes

• align: center/end/justify/left/right/start/-moz-center/-webkit-center
• dir: auto/ltr/rtl

Inline stylings

• background (color only), background-color: hex values, rgb(), hsl() or named colors
• border, border-xxx and box-sizing
• color: hex values, rgb(), hsl() or named colors
• direction (similar to dir attribute)
• font-family
• font-size: absolute (e.g. xx-large), relative (larger, smaller) or values in em, %, pt and px
• font-style: italic/normal
• font-weight: bold/normal/100..900
• line-height: normal, number or values in em, %, pt and px
• margin and margin-xxx: values in em, pt and px
• padding and padding-xxx: values in em, pt and px
• vertical-align: baseline/top/bottom/middle/sub/super
• text-align (similar to align attribute)
• text-decoration: line-through/none/overline/underline
• text-overflow: clip/ellipsis. Note: text-overflow: ellipsis should be used in conjuntion with max-lines or -webkit-line-clamp for better result.
• Sizing (width, height, max-xxx, min-xxx): auto or values in em, %, pt and px

Extensibility

See flutter_widget_from_html_core for details.