====== lmbFileSchema ======

===== Description =====

lmbFileSchema is a mechanism used in Limb to find full file paths by short aliases. lmbFileSchema is used by different class factories, template engine, etc.

===== UML Static structure =====

{{{ limb:architecture:limb3.0_file_schema.png }}}

===== Comments =====

Here is the sample code that uses lmbToolkit to get access to lmbFileSchema in order to locate full file path of a command:
<code php>
  $file_schema = lmbToolkit :: instance()->getFileSchema();
  $command_full_path = $file_schema->locateCommand($alias = 'Set404ErrorCommand');
  require_once($command_full_path);
</code>

lmbFileSchema delegates file name resolving to different file locators. [[lmbFileLocator]] implements the following interface:

<code php>
interface FileLocatorInterface
{
  function locate($alias, $params);
  function getLocations();
}
</code>

The delegation looks like this:
<code php>
class lmbFileSchema
{ 
  protected $command_locator; 
  [...]
  function locateCommand($alias)
  {
    return $this->command_locator->locate($alias);
  }
}
</code>

File locators look for files in different locations(folders) which they receive from [[lmbFileLocations]]. lmbFileLocations interface consists of the only getLocations method returning an array of folders where file should be searched:
<code php>
interface lmbFileLocations
{
  function getLocations();
}
</code>

lmbFileSchema has factory methods to create FileLocators so you can extend lmbFileSchema and create concrete FileLocators you need:

<code php>
class MyLimbFileSchema extends lmbFileSchema
{ 
  [...]
  protected function _createCommandLocator()
  {
    $locations = new lmbAndPackagesFileLocations();
    return new lmbCachingFileLocator(new lmbFileLocator($locations, '/command/%s.class.php'));
  } 
</code>

In this example we create caching CommandLocator that will look for files in LPKG_CORE_DIR and in packages applying '/command/%s.class.php' pattern. For example if asked to locate "lmbBaseCommand" alias, it will return 'LPKG_CORE_DIR/src/command/lmbBaseCommand.class.php'

===== Frequently used classes =====

^Class name^Description^
|[[lmbFileLocationsList]]|Allows you to create compound lmbFileLocations.|
|[[lmbPackagesFileLocations]]|Returns paths to packages install for a Limb-based application. Uses [[lmbPackagesInfo]] to get information about installed packages.|
|[[TemplateFileLocations]]|Returns paths where template files should be looked for. Takes into account current locale and common.ini file setting: templates_path and shared_templates_path.|