Validating xml with perl dating differences between generations
Schematron may not completely replace DTDs or W3C Schemas for stricter XML systems, but the value that it provides for the minimal time investment makes it a big winner in my book.
At the time of this writing, XML:: Lib XML could only validate with DOM parsing—validation is not available with SAX-style parsing.
Any valid XPath expression that can be evaluated as true or false can be used to test a document's structure. /usr/bin/perl -w use strict; use XML:: Schematron:: Lib XSLT; my $schema_file = $ARGV; my $xml_file = $ARGV; die "Usage: perl schemafile XMLfile.\n" unless defined $schema_file and defined $xml_file; my $tron = XML:: Schematron:: Lib XSLT-.
When the form is submitted the preview section is updated.With the exception of XHTML, XML languages are completely foreign to HTML browsers.You may get a nice colorized tree representing an entire XML document in some, but that is a far cry from the "if it renders correctly here, it will render correctly most anywhere" that goes along with checking HTML markup in an HTML browser.There are W3C Schemas, but there, too, the entire model must be described, and the technology itself seems a bit biased toward the stricter "data transfer" uses of XML rather the looser models that characterize human communication.DTDs and W3C Schemas have their place, but the learning curve involved in getting it right in order provide a useful level of content validation make their use for most applications impractical. Created by Rick Jelliffe, Schematron is a simple XML application language designed to make validating the structures of XML documents as straightforward and painless as possible.
Schematron's secret is that it's most often implemented as an XSLT stylesheet, in which the Schematron stylesheet is applied to the schema and the result of that transformation is applied as a stylesheet to the document being validated.