XMLIterator

Description

XMLIterator is a low level synchronous XML parser implemented as an ECMAScript iterator.

It takes a String containing a whole XML document and parses it giving out a sequence of XMLNode.

Nodes come isolated: parent and children fields are all null. It's up to API users to build hierarchies when necessary (or just to use XMLParser to get the complete document tree).

For self enclosed tags, a pair of objects (StartElement / EndElement) is emitted.

Usage

  const xml = fs.readFileSync ('small.xml', 'utf-8')
	
  for (const node of new XMLIterator (xml, {})) 
    if (node.isStartElement && node.localName === 'user') 
      return node.attributes.get ('id')  

Options

Name	Default	Description
entityResolver	EntityResolver	to be used with generated XMLNodes

Comparison to XMLLexer

XMLLexer and XMLIterator and are both low level XML parsers splitting pointy bracket delimited text to syntactically atomic tokens. But:

Name	Proto	XML Source	Pro	Contra
XMLLexer	Transform	Readable	limited memory footprint with any XML size	asynchronous by nature
XMLIterator	Iterable	String	can be used in synchronous for ... of, e. g. in object constructors	limited size XML only

So, XMLLexer vs. XMLIterator is basically like fs.createReadStream vs. fs.readFileSync.

Comparison to XMLParser

XMLParser and XMLIterator and are both synchronous XML parsers reading a complete String. But:

Name	Proto	Pro	Contra
XMLIterator	Iterable	scans XML tag by tag, allows early completion	doesn't build hierarchy
XMLParser	none	simple	always allocates the complete document tree in memory

In fact, XMLParser is built on top of XMLIterator.