HTML5 Parser

Introduction

dompdf includes an experimental HTML5 parser: html5lib. It can be activated by setting DOMPDF_ENABLE_HTML5PARSER to true.

What is an HTML5 parser?

An HTML parser is a library or software able to read an HTML source code and translate it into a DOM tree.

The difference between a regular HTML parser and an HTML5 parser is that the latter knows how to deal with badly structured HTML code as all the cases are strictly defined in W3C specifications.

What does it mean for dompdf?

Having an HTML5 parser, dompdf will be able to handle more poorly written HTML documents.

For example, it happens that a table element has rows without closing tr elements. A regular HTML parser (the one embedded with the PHP DOM extension: libxml) won't be able to handle it well and may, for example, ignore this line or append the next cells to the current line. An HTML5 parser will handle it like if the </tr> tag is present.