The WHATWG Blog

Validator.nu HTML Parser 1.1.0

August 25th, 2008 by Henri Sivonen in Syntax

I have released a new version of the Validator.nu HTML Parser (an implementation of the HTML5 parsing algorithm in Java). The new release supports SVG and MathML subtrees, is faster than the old version, fixes bugs, is more portable and supports applications that want to do document.write().

The parser comes with a sample app that makes it possible to use XSLT programs written for XHTML5+SVG+MathML with text/html.

Warning! The internal APIs have changed. Please refer to the Upgrade Guide below.

Change Log

• Made the SAX, DOM and XOM parser entry point constructors default to altering the infoset instead of throwing when the input needs coercing to be an XML 1.0 4th ed. plus Namespaces infoset.
• Isolated Java IO dependent code from the parser core. The parser core now compiles on Google Web Toolkit.
• Refactored the tokenizer to use a switch branch per state instead of method per state.
• Made various performance tweaks to the tokenizer.
• Implemented support for MathML and SVG foreign content. (Note that the SVG part is based on spec text that has been commented out from the spec at the request of the SVG WG.)
• Made the parser suspendable after any input character.
• Made it possible for custom TreeBuilder subclasses to request parser suspension. (Applications wishing to implement document.write() should provide their own TreeBuilder subclass and a document.write()-aware replacement of the Driver class. Look in the gwt-src/ directory for sample code.)
• Made changes to the parser core to make it more suitable for mechanical translation into other object-oriented programming languages that have C-like control structures but not necessarily a garbage collector (with focus on targeting C++). This work is not complete.
• Made the HTML serializer do the right thing when input represents a conforming XHTML+SVG+MathML tree. (Results may be bad for non-conforming input trees.)
• Developed sample programs for converting between HTML5 and XHTML5 when the input is known to be conforming.
• Provided an XML serializer so that the sample code no longer depends on the Xalan serializer.
• Improved API documentation.
• Fixed bugs in the tokenizer, tree builder and the input stream character encoding decoder.
• Made coercion to an XML infoset work according to the HTML5 spec.
• Added ID uniqueness checking.
• Various other fixes.

Upgrade Guide from 1.0.7 to 1.1.0

In all cases, you need to check that your application does not break when it receives SVG or MathML subtrees.

If you use the parser through the SAX, DOM or XOM API and do not pass an explicit XmlViolationPolicy to the constructor of HtmlParser, HtmlDocumentBuilder or HtmlBuilder:

If you really wanted the old default behavior, you should now pass XmlViolationPolicy.FATAL to the constructor.

If you did not really want to have fatal errors by default, you do not need to do anything, since ALTER_INFOSET is now the default.

If you use the parser through the SAX, DOM or XOM API and do pass an explicit XmlViolationPolicy to the constructor of HtmlParser, HtmlDocumentBuilder or HtmlBuilder:

You do not need to change your code to upgrade.

If you have your own subclass of TreeBuilder:

The abstract methods on TreeBuilder now have additional arguments for passing the namespace URI. You should upgrade your subclass to deal with the namespace URIs. (The URI is always an interned string, so you can use == to compare.)

The entry point for passing in a SAX InputSource has moved from the Tokenizer class to the Driver class (in the io package), so you should change your references from Tokenizer to Driver.

If you have your own implementation of TokenHandler:

Please refer to the JavaDocs of TokenHandler. Also note the new separation of Tokenizer and Driver mentioned above.

This Week in HTML 5 – Episode 3 ↔ This Week in HTML 5 – Episode 4