Data::DumpXML(3) Dump arbitrary data structures as XML


This module provides a single function called dump_xml() that takes a list of Perl values as its argument and produces a string as its result. The string returned is an XML document that represents any Perl data structures passed to the function. Reference loops are handled correctly.

The following data model is used:

   data : scalar*
   scalar = undef | str | ref | alias
   ref : scalar | array | hash | glob | code
   array: scalar*
   hash: (key scalar)*

The distribution comes with an XML schema and a DTD that more formally describe this structure.

As an example of the XML documents produced, the following call:

  $a = bless [1,2], "Foo";


  <?xml version="1.0" encoding="US-ASCII"?>
  <data xmlns="">
    <array class="Foo">

If dump_xml() is called in a void context, then the dump is printed on STDERR automatically. For compatibility with "Data::Dump", there is also an alias for dump_xml() called simply dump().

"Data::DumpXML::Parser" is a class that can restore data structures dumped by dump_xml().

Configuration variables

The generated XML is influenced by a set of configuration variables. If you modify them, then it is a good idea to localize the effect. For example:

  sub my_dump_xml {
      local $Data::DumpXML::INDENT = "";
      local $Data::DumpXML::XML_DECL = 0;
      local $Data::DumpXML::DTD_LOCATION = "";
      local $Data::DumpXML::NS_PREFIX = "dumpxml";

      return dump_xml(@_);

The variables are:

You can set the variable $Data::DumpXML::INDENT to control the amount of indenting. The variable contains the whitespace you want to be used for each level of indenting. The default is a single space. To suppress indenting, set it to "".
This variable controls where end element are placed. If you set this variable to the value ``Lisp'' then end tags are not prefixed by NL. This give a more compact output.
This boolean variable controls whether an XML declaration should be prefixed to the output. The XML declaration is the <?xml ...?> thingy. The default is 1. Set this value to 0 to suppress the declaration.
This variable contains the namespace used for the XML elements. The default is to let this be a URI that actually resolve to the XML schema on CPAN. Set it to "" to disable use of namespaces.
This variable contains the namespace prefix to use on the elements. The default is "", which means that a default namespace will be declared.
This variable contains the location of the XML schema. If this variable is non-empty, then an "xsi:schemaLocation" attribute is added to the top level "data" element. The default is not to include this, as the location can be inferred from the default XML namespace used.
This variable contains the location of the DTD. If this variable is non-empty, then a <!DOCTYPE ...> is included in the output. The default is to point to the DTD on CPAN. Set it to "" to suppress the <!DOCTYPE ...> line.