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XML::Simple - Trivial API for reading and writing XML (esp config files)

XML::Simple loads an XML file in memory, in a convenient structure, that can be accessed and updated, then output back.
A number of options allow users to specify how the structure should be built. It can also be cached using Data::Dumper

Why use XML::Simple?

  • XML configuration files, small table, data-oriented XML
  • simple XML processing
  • you don't care much about XML but find it convenient as a standard file format, to replace csv or a home-brewed format

Why NOT use XML::Simple?

  • your XML data is too complex for XML::Simple to deal with:
    - it includes mixed content (<elt>th<is>_</is>_ mixed content</elt>)
    - your documents are too big to fit in memory
    - you are dealing with XML documents
  • you want to use a standard-based module (XML::DOM for example)

Personal notes

I don't use XML::Simple in production but the module seems quite mature, and very convenient for "light" XML: config files, tables, generally data-oriented, shallow XML (the XML tree is not really deep), as opposed to document-oriented XML.

Update: make sure you read the documentation about the forcearray option or you might get bitten by repeated elements being turned into an array (which is OK) _except_ when there is only one of them, in which case they become just a hash value (bad!).
for example this document:

<config dir="/usr/local/etc" log="/usr/local/log"> <user id="user1"> <group>root</group> <group>webadmin</group> </user> <user id="user2"> <group>staff</group> </user> </config>
when loaded with XMLin and not forcearray option becomes
{ 'dir' => '/usr/local/etc', 'log' => '/usr/local/log', 'user' => {'user1' => {'group' => ['root', 'webadmin']}, 'user2' => {'group' => 'staff'} } };
Note the 2 different ways the group elements are processed.

I also found that XML::Simple can be a little dangerous in that it leads to writing XML that is a little too simple. Often when using it I end up with an XML structure that's as shallow as I can possibly make it, which might not be really clean.

In reply to XML::Simple by mirod

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