XML::Simpler - Simpler API for handling XML
my $ref = XMLin($filename);
In the years since XML::Simple was released, many people have taken the time to email me suggestions for how the module could be improved.
It rapidly became apparent to me that what these people wanted could not be achieved through small changes to XML::Simple (even though most correspondents expressed opinions to the contrary).
The recurring complaints were:
- XML::Simple does not always preserve element order
- When XML is written out, elements can get translated into attributes
- The original encoding is not maintained when the file is read
The data structures returned by
XMLin()are too complex
- There are too many options
- There is too much documentation
Clearly a whole new approach was required and so XML::Simpler was born...
XML::Simpler offers the following improvements over XML::Simple:
- Element order is always preserved
- Elements are never translated into attributes
- Indentation and whitespace is preserved
- Absolutely no encoding translations are performed (unless the 'utf8' option is enabled - see below)
In addition to these changes, the data structures returned by
XMLin() have been
vastly simplified. All hashrefs and arrayrefs have been eliminated, and
instead the contents of the XML file are represented using a single scalar
value which perfectly preserves the fidelity of the original document. In fact
the format of this data structure is so intuitive that new users will be able
to work with it immediately without reading the documentation.
The new data structure offers a number of exciting possibilities:
- The need for documents to comply with the strict (and often inconvenient) syntax rules defined in the W3C XML Recommendation has been relaxed.
- It is no longer necessary to use an encoding declaration when pasting in accented characters, symbols and 'smart quotes' from MS Word (in fact you can mix multiple encodings in the same file).
- It is also possible to embed HTML (including unbalanced or unclosed tags) in your files without having to resort to CDATA sections.
Furthermore, the new data structure and relaxed rules mean that XML::Simpler is not restricted to XML data. In fact the new module works equally well with INI files, CSV files and all of the 'dot file' formats commonly used on Unix systems.
In the absence of hash keys and array indexes, users will need to adopt
different techniques for extracting individual data values. The most popular
approach will likely be regular expressions but this is Perl and there is
always more than one way to do it, so
substr() are likely to be popular alternatives.
XML::Simple's object oriented API has been discarded in favour of the simpler procedural interface. These two routines are exported by default:
For compatibility with XML::Simple, this method is named
XMLin() but as
described above it should work with most file formats. It takes a filename and
returns the contents of the file represented as a single scalar value (no
nested hashrefs etc).
This method can be used to write data out to an XML (or other) format file.
It takes a scalar value in the format returned by
XMLin() and a filename.
The contents of the scalar is written to the named file.
Perhaps surprisingly, all this added flexibility comes with a vastly simplified
API. In fact the new API supports only one option: 'utf8'. This option is
disabled by default but if it is enabled,
XMLin() will auto-detect the encoding
and convert the data to UTF-8.
This option will not be fully implemented until Perl version 5.8 (or perhaps 6.0). In the current release, enabling this option will cause your data to be replaced with a pseudo-random character string of approximately the same length. As many of my correspondents have pointed out, UTF-8 encoded data is virtually indistinguishable from random characters anyway so the current implementation should tide us over for some time.
XML::Simpler does not require XML::Parser or a SAX parser. It does require File::Slurp.
The 'utf8' option requires that your system implements /dev/random, however on Win32 platforms the system registry has been found to offer equivalent functionality.
Version 1.00 of XML::Simpler was released on April 1st, 2002
Copyright 2002 Grant McLean <firstname.lastname@example.org>
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.