1: <?php
  2: 
  3: namespace Charcoal\View;
  4: 
  5: // PSR-3 (logger) dependencies
  6: use \Psr\Log\LoggerAwareInterface;
  7: use \Psr\Log\LoggerAwareTrait;
  8: 
  9: // Local namespace dependencies
 10: use \Charcoal\View\EngineInterface;
 11: use \Charcoal\View\LoaderInterface;
 12: 
 13: /**
 14:  * Default implementation, as abstract class, of the `EngineInterface`.
 15:  *
 16:  * View Engines are comprised of 2 things:
 17:  * - A template loader, wich is a `LoaderInterfaceObject`
 18:  *   - Set with `set_loader()` / Get with `loader()`
 19:  *   - Provides `loadtemplate()` method
 20:  * - A `render()` method, which takes a $template and a $context arguments
 21:  *
 22:  * > Engines implements the `LoggerAwareInterface`. A logger can be accessed with the `logger()` method.
 23:  */
 24: abstract class AbstractEngine implements
 25:     EngineInterface,
 26:     LoggerAwareInterface
 27: {
 28:     use LoggerAwareTrait;
 29: 
 30:     /**
 31:      * @var LoaderInterface $loader
 32:      */
 33:     private $loader;
 34: 
 35:     /**
 36:      * @return string
 37:      */
 38:     abstract public function type();
 39: 
 40:     /**
 41:      * Build the object with an array of dependencies.
 42:      *
 43:      * ## Required parameters:
 44:      * - `logger` a PSR-3 logger
 45:      *
 46:      * ## Optional parameters:
 47:      * - `loader` a Loader object
 48:      *
 49:      * @param array $data Engine dependencie.
 50:      */
 51:     public function __construct(array $data)
 52:     {
 53:         $this->setLogger($data['logger']);
 54:         $this->setLoader($data['loader']);
 55:     }
 56: 
 57:     /**
 58:      * @param LoaderInterface $loader A loader instance.
 59:      * @return void
 60:      */
 61:     private function setLoader(LoaderInterface $loader)
 62:     {
 63:         $this->loader = $loader;
 64:     }
 65: 
 66:     /**
 67:      * @return LoaderInterface
 68:      */
 69:     protected function loader()
 70:     {
 71:         return $this->loader;
 72:     }
 73: 
 74:     /**
 75:      * Delegates template loading to the engine's Loader object.
 76:      *
 77:      * @param string $templateIdent The template identifier to load.
 78:      * @return string The template string, loaded from identifier.
 79:      */
 80:     public function loadTemplate($templateIdent)
 81:     {
 82:         return $this->loader()->load($templateIdent);
 83:     }
 84: 
 85:     /**
 86:      * @param string $templateIdent The template identifier to load and render.
 87:      * @param mixed  $context       The rendering context.
 88:      * @return string The rendered template string.
 89:      */
 90:     public function render($templateIdent, $context)
 91:     {
 92:         $template = $this->loadTemplate($templateIdent);
 93:         return $this->renderTemplate($template, $context);
 94:     }
 95: 
 96:     /**
 97:      * @param string $templateString The template string to render.
 98:      * @param mixed  $context        The rendering context.
 99:      * @return string The rendered template string.
100:      */
101:     abstract public function renderTemplate($templateString, $context);
102: }
103: