XML Parsers

Everything you need to know about parsing XML – without being baffled by long winded ramblings and flag waving for the latest/greatest frameworks.

There are 2 basic parsing strategies with XML.

1. DOM – Document/tree based strategy.
2. SAX – event based strategy.

DOM

  • Simple.
  • Nested tree structure.
  • Process and query with XPath or other parser supported functions.
  • Implements specific interface defined by W3C.
  • You have to load the whole document into memory – so if the XML is big – then you have to watch out.
  • Simple and large XML documents do not suit this style.
  • Random access to the document.

SAX

  • Complex to use.
  • Event based.
  • Starting/Ending tags, XML comments and entity declarations all raise events.
  • Flexible – you can handle events when needed, and take action on those events as they are raised.
  • Once events have been fired they are gone, you have to re-read the document again if you need to get back to the same bit of XML again.
  • Malformed XML can cause the code to fall into exception – make sure your document is well formed before passing to the parser.

C# and Java XML Implementations

C#

  • Look at System.Xml.XmlReader.
  • DOM trees can be used via XmlDocument – and XPathDocument lets you interrigate the tree nodes via XPath.

Java (1.5)

  • If you are using 1.5 you are in luck as this version includes the Apache Xerces project.
  • Look at packages javax.xml.* – this also has XPath functionality.
  • DOM functionality can be found in org.w3c.dom.*
  • If you are using Java 1.4 and below, you will have to install Xerces.
Advertisements
XML Parsers

Asus Maximus II Formula Motherboard Design Fault

Got one of these babies the other day to swap out my existing dud motherboard.  It is quite nice and also comes with a X-Fi sound module (SupremeFX X-Fi Audio Card) that plugs into the motherboard – bonus!

Problem is that the fit of this sound module conflicts with the motherboard layout i.e. it can rest on top of the mounting screw, as the hole for the mouting screw is right underneath where the sound module would go – this will cause a short and cause your PC not to start up i.e. you will be able to switch the PC on – but the fans will work for 3 seconds and then it cuts out.

Simple thing to do is remove the mouting screw that is resting against the sound module.  You don’t necessarily need all the mounting screws in the motherboard to make it secure.   After you have done this your PC should boot up normally.

Asus Maximus II Formula Motherboard Design Fault