Tuesday, January 20, 2009

XML Naming Conventions (Best Practices)

XML is the base of Web 2.0 development. While writing a web service to integrate products, I learned some best practices with XML naming conventions.

An XML element is everything from (including) the element's start tag to (including) the element's end tag.

An element can contain other elements, simple text or a mixture of both. Elements can also have attributes.

<bookstore>
<book category="CHILDREN">
<author>J K. Rowling</author>
<year>2005</year>
<price>29.99</price>
</book>
<book category="WEB">
<author>Erik T. Ray</author>>
<year>2003</year>
<price>39.95</price>
</book>
</bookstore>>

In the example above, and have element contents, because they contain other elements. has text content because it contains text.

In the example above only has an attribute (category="CHILDREN").

XML Naming Rules

XML elements must follow these naming rules:

1. Names can contain letters, numbers, and other characters
2. Names cannot start with a number or punctuation character
3. Names cannot start with the letters xml (or XML, or Xml, etc)
4. Names cannot contain spaces

Any name can be used, no words are reserved.

Best Naming Practices

1. Make names descriptive. Names with an underscore separator are nice: , .
2. Names should be short and simple, like this: not like this: .
3. Avoid "-" characters. If you name something "first-name," some software may think you want to subtract name from first.
4. Avoid "." characters. If you name something "first.name," some software may think that "name" is a property of the object "first."
5. Avoid ":" characters. Colons are reserved to be used for something called namespaces (more later).
6. XML documents often have a corresponding database. A good practice is to use the naming rules of your database for the elements in the XML documents.
7. Non-English letters like éòá are perfectly legal in XML, but watch out for problems if your software vendor doesn't support them.

Reference : http://www.w3schools.com/xml/xml_elements.asp

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