Benjamin Holzman

By a curious coincidence, I had already started to use XML to build configuration files for applications written in Perl, using XML::Parser to turn the XML into a perl data structure. I'd like to share with you some tips and tricks that you can make use of the next time you need to drive a program with a configuration file.

Outline:

• The basic structure of using XML::Parser to create a data structure from a simple configuration file.
  • Configuration elements are specified as elements and attributes thereof.
  • Any other text in the document is considered a comment.

• Putting this parsing code into a module.
  • as a parser class which embeds an XML::Parser.
  • as ->new_from_xml methods in classes representing the structure present in the configuration file.

• Allowing a <?include ...?> processing instruction to enable a single configuration file to be split into a number of configuration files.

• Adding validity checks

• Dealing with multi-valued configuration elements
  • as repeating elements
  • as multi-valued attributes

• Allowing recursion in the configuration file

• Simplifying configuration-file creation with XML::Generator