Validating xml with perl
XML:: Xerces requires the Apache Xerces C XML parsing library, available from Michael, XML:: Parser has all the workings of a validating parser, and libxml-enno includes a parser that will validate against a DTD, XML:: Parser:: Checker I think, someone will correct me if I'm wrong.Currently, the Sablotron and Lib XSLT processors are supported, but if you do not have or want an XSLT processor installed, you may use interface that will validate that content and warn the user about any validation errors that may have been encountered.To avoid information overload we will focus on the parts that are directly relevant to validating the submitted content and warning the user about any errors encountered.This ubiquity made web-based applications possible. By having a common, albeit limited language from which to build user interfaces, client-server applications could often abandon the use of platform- and application-specific client-side executables in favor of accessing data and logic on the server through the CGI or Web server extension.The importance of HTML's ubiquity in web applications is especially noticeable in the class of applications I'll call "in-browser content editors".
Choosing XML to markup web content knocks that implicit validation into a cocked hat.
It uses the XPath syntax to define a series of rules that should or should not be true about a given document's structure.
Those rules, and the context in which they are evaluated, can be as coarse or as finely-grained as the task at hand requires.
Content models may be open or closed; you can declare a document structurally valid based on a single all-important rule; or you can create rules for each and every element and attribute that may appear in the document -- the choice is yours.
This month we will be looking at the Perl implementation of the Schematron: my element in the context of the abstract root.