You can create fake filesystems for PHPTAL templates. This lets you load templates and macros from any source, e.g. a database.

If you don't use macros, you don't need SourceResolver:

   $phptal->setSource(load_source_from_anywhere());  // No source resolver necessary

However, if you'd like to avoid fetching template source on every request (explained later), or would like to use macros that load additional templates, implement your own SourceResolver:

   class MySourceResolver implements PHPTAL_SourceResolver
   {
       function resolve($path)
       {
           if (looks_like_my_path($path)) {
               $source = load_template_from($path);
               return new PHPTAL_StringSource($source);
           }
       }
   }

(in PHPTAL older than 1.2.2 you need new PHPTAL_StringSource($source, md5($source)))

The resolve function should return instance of PHPTAL_Source (if it supports the path) or NULL. You can either use PHPTAL_StringSource class, or implement your own.

   $phptal->addSourceResolver(new MySourceResolver());

PHPTAL will call resolve() method whenever it needs to load a template set via setTemplate() or metal:use-macro. ()

PHPTAL_SourceResolver::resolve() method could return object that doesn't load template immediately, and instead just returns information needed to load compiled template from cache:

  class MyLazyTemplate extends PHPTAL_Source
  {
      function getRealPath()
      {
          return 'fake:/my/template'; // doesn't have to be on disk
      }
      
      function getLastModifiedTime()
      {
          return mktime(0,0,0, 7,7,2010); // unix timestamp
      }
      
      function getData()
      {
          return load_the_template();
      }
  }

PHPTAL will call getData() only when getRealPath() or getLastModifiedTime() return different values.()