Core PHP Programming, Third Edition

27.6. Templates

Another approach to modularizing PHP applications can be called templatizing. Loose coupling is a fundamental principle of good system design. Aside from avoiding confusing people who don't understand PHP, a separation offers the benefit of switching to a different presentation language, such as XML, without disturbing the business logic.

Using templates, interface designers insert simple tags into prototypical files (templates) composed mostly of HTML. They insert short bits of a simple templating language that a PHP script parses in order to replace markers with generated information.

As with most solutions, there's a tradeoff. The cost of a templating system is increased work for PHP with each page load. PHP includes an efficient ...