NWMatcher

A fast CSS selector engine and matcher.

Installation

To include NWMatcher in a standard web page:

<script type="text/javascript" src="nwmatcher.js"></script>

To use it with Node.js:

$ npm install nwmatcher

NWMatcher currently supports browsers (as a global, NW.Dom) and headless environments (as a CommonJS module).

Supported Selectors

Here is a list of all the CSS2/CSS3 Supported selectors.

Features and Compliance

You can read more about NWMatcher features and compliance on the wiki.

API

DOM Selection

first( selector, context )

Returns a reference to the first element matching selector, starting at context.

match( element, selector, context )

Returns true if element matches selector, starting at context; returns false otherwise.

select( selector, context, callback )

Returns an array of all the elements matching selector, starting at context. If callback is provided, it is invoked for each matching element.

DOM Helpers

byId( id, from )

Returns a reference to the first element with ID id, optionally filtered to descendants of the element from.

byTag( tag, from )

Returns an array of elements having the specified tag name tag, optionally filtered to descendants of the element from.

byClass( class, from )

Returns an array of elements having the specified class name class, optionally filtered to descendants of the element from.

byName( name, from )

Returns an array of elements having the specified value name for their name attribute, optionally filtered to descendants of the element from.

getAttribute( element, attribute )

Return the value read from the attribute of element with name attribute, as a string.

hasAttribute( element, attribute )

Returns true element has an attribute with name attribute set; returns false otherwise.

Engine Configuration

configure( options )

The following is the list of currently available configuration options, their default values and descriptions, they are boolean flags that can be set to true or false:

• CACHING: false - false to disable caching of result sets, true to enable
• ESCAPECHR: true - true to allow CSS escaped identifiers, false to disallow
• NON_ASCII: true - true to allow identifiers containing non-ASCII (utf-8) chars
• SELECTOR3: true - switch syntax RE, true to use Level 3, false to use Level 2
• UNICODE16: true - true to allow identifiers containing Unicode (utf-16) chars
• SHORTCUTS: false - false to disable mangled selector strings like "+div" or "ul>"
• SIMPLENOT: true - true to disallow complex selectors nested in ':not()' classes
• SVG_LCASE: false - false to disable matching lowercase tag names of SVG elements
• UNIQUE_ID: true - true to disallow multiple elements with the same id (strict)
• USE_HTML5: true - true to use HTML5 specs for ":checked" and similar UI states
• USE_QSAPI: true - true to use browsers native Query Selector API if available
• VERBOSITY: true - true to throw exceptions, false to skip throwing exceptions
• LOGERRORS: true - true to print console errors or warnings, false to mute them

Example:

NW.Dom.configure( { USE_QSAPI: false, VERBOSITY: false } );

registerOperator( symbol, resolver )

Registers a new symbol and its matching resolver in the operators table. Example:

NW.Dom.registerOperator( '!=', 'n!="%m"' );

registerSelector( name, rexp, func )

Registers a new selector, with the matching regular expression and the appropriate resolver function, in the selectors table.