Office of Digital Humanities

Introduction to XML

What is XML? (From w3schools.com)

XML stands for EXtensible Markup Language.

XML was designed to describe data.

XML is a software- and hardware-independent tool for carrying information.

See this concise description: http://www.w3schools.com/xml/xml_whatis.asp (first two pages)

HTML is similar in format to XML, but is designed for a different purpose.

• XML was designed to describe data, with focus on what data is
• HTML was designed to display data, with focus on how data looks

HTML is about displaying information, while XML is about carrying information.

Key concept: "[An] XML document does not DO anything. It is just information wrapped in tags. Someone must write a piece of software to send, receive or display it."

Sample XML:

<?xml version="1.0"?>
<employeeTable>
	<employee IDnum="1">
		<firstName>Steve</firstName>
		<lastName>Jobs</lastName>
		<roomNum>001</roomNum>
		<phoneExt>345</phoneExt>
		<parkingSlot>100</parkingSlot>
	</employee>
	<employee IDnum="2">
		<firstName>Bill</firstName>
		<lastName>Gates</lastName>
		<roomNum>284</roomNum>
		<phoneExt>666</phoneExt>
		<parkingSlot>987</parkingSlot>
	</employee>
	<employee IDnum="3">
		<firstName>Linus</firstName>
		<lastName>Torvald</lastName>
		<roomNum>43</roomNum>
		<phoneExt>479</phoneExt>
		<parkingSlot>123</parkingSlot>
	</employee>
	<employee IDnum="4">
		<firstName>Kevin</firstName>
		<lastName>Miller</lastName>
		<roomNum>100</roomNum>
		<phoneExt>421</phoneExt>
		<parkingSlot>987</parkingSlot>
	</employee>
</employeeTable>

LiveCode has tools for working with XML built into the language. See references for "revXML..." in the LiveCode Dictionary. However, these XML tools can be a little complicated to work with. The good news is that there are a few third-party XML scripts that will convert an XML text to an array and vice-versa. One good example can be found at https://gist.github.com/trevordevore/5584753.