Awesome

MyHTML

Fast HTML5 Parser (Crystal binding for awesome lexborisov's myhtml and Modest). This shard used in production to parse millions of pages per day, very stable and fast.

WARNING: original libraries (myhtml and Modest) not maintained since july 2020, i recommend switch to successor parser: Lexbor.

Installation

Add this to your application's shard.yml:

dependencies:
  myhtml:
    github: kostya/myhtml

And run shards install

Usage example

require "myhtml"

html = <<-HTML
  <html>
    <body>
      <div id="t1" class="red">
        <a href="/#">O_o</a>
      </div>
      <div id="t2"></div>
    </body>
  </html>
HTML

myhtml = Myhtml::Parser.new(html)

myhtml.nodes(:div).each do |node|
  id = node.attribute_by("id")

  if first_link = node.scope.nodes(:a).first?
    href = first_link.attribute_by("href")
    link_text = first_link.inner_text

    puts "div with id #{id} have link [#{link_text}](#{href})"
  else
    puts "div with id #{id} have no links"
  end
end

# Output:
#   div with id t1 have link [O_o](/#)
#   div with id t2 have no links

Css selectors example

require "myhtml"

html = <<-HTML
  <html>
    <body>
      <table id="t1">
        <tr><td>Hello</td></tr>
      </table>
      <table id="t2">
        <tr><td>123</td><td>other</td></tr>
        <tr><td>foo</td><td>columns</td></tr>
        <tr><td>bar</td><td>are</td></tr>
        <tr><td>xyz</td><td>ignored</td></tr>
      </table>
    </body>
  </html>
HTML

myhtml = Myhtml::Parser.new(html)

p myhtml.css("#t2 tr td:first-child").map(&.inner_text).to_a
# => ["123", "foo", "bar", "xyz"]

p myhtml.css("#t2 tr td:first-child").map(&.to_html).to_a
# => ["<td>123</td>", "<td>foo</td>", "<td>bar</td>", "<td>xyz</td>"]

More Examples

examples

Development Setup:

git clone https://github.com/kostya/myhtml.git
cd myhtml
make
crystal spec

Benchmark

Parse 1000 times google page(600Kb), and 1000 times css select. myhtml-program, crystagiri-program, nokogiri-program

Lang	Shard	Lib	Parse time, s	Css time, s	Memory, MiB
Crystal	lexbor	lexbor	2.54	0.099	7.8
Crystal	myhtml	myhtml(+modest)	3.17	0.16	8.4
Ruby 2.7	Nokogiri	libxml2	9.19	10.76	139.8
Crystal	Crystagiri	libxml2	11.27	-	25.0