Wednesday, 25 April 2007

Article: Learn to Validate XML Files within PHP4 Applications

Raphael Stolt while importing XML data against a DTD (Document Type Definition), discovered a solution to solve his problem of validating without using PHP4. PHP 4 wasn't supporting the Document Object Model (DOM) XML functions, so he didn’t favour it.

Instead he used Xmllint, a command line XML tool. This tool parses XML files and can be used to verify that the files are well formed and are working according to an associated DTD/XML Schema.

He demonstrates a method body, which shows an example call of the Xmllint tool for validating a given XML file against a DTD. The location of the DTD file is wrapped inside a DOCTYPE definition of the import file and will be automatically resolved by Xmllint.

He concludes by saying that Xmllint is helpful when writing custom DTDs or XML Schema, as you get an immediate reply regarding the correctness of the definition rules and their 'impact' on the associated XML files.