Adds event "twigLoaderPreInit.customize" that allows manipulation of …

…Twig Loaders before Init of Twig Environment.

src/PatternLab/PatternEngine/Twig/Loaders/PatternLoader.php

@@ -64,13 +64,26 @@ public function __construct($options = array()) {
 		// set-up the loader list in order that they should be checked
 		// 1. Patterns 2. Filesystem 3. String
 		$loaders   = array();
+		// 1. add Patterns
 		$loaders[] = new Twig_Loader_PatternPartialLoader(Config::getOption("patternSourceDir"),array("patternPaths" => $options["patternPaths"]));
 
-		// add the paths to the filesystem loader if the paths existed
+		// 2. add the paths to the filesystem loader if the paths existed
 		if (count($filesystemLoaderPaths) > 0) {
 			$filesystemLoader = new \Twig_Loader_Filesystem($filesystemLoaderPaths);
 			$loaders[] = TwigUtil::addPaths($filesystemLoader, $patternSourceDir);
 		}
+
+		// Setting loaders and giving plugins a chance to manipulate them
+		TwigUtil::setLoaders($loaders);
+		// set-up the dispatcher
+		$dispatcherInstance = Dispatcher::getInstance();
+		$dispatcherInstance->dispatch("twigLoaderPreInit.customize");
+		// getting the loaders back
+		$loaders = TwigUtil::getLoaders();
+
+		// 3. add String loader
+		// This *must* go last or no loaders after will work ~ https://github.com/symfony/symfony/issues/10865
+		// @todo Remove `Twig_Loader_String` - if a Twig include path is wrong, this outputs the string anyway with no error ~ https://github.com/symfony/symfony/issues/10865
 		$loaders[] = new \Twig_Loader_String();
 
 		// set-up Twig
@@ -87,8 +100,6 @@ public function __construct($options = array()) {
 		TwigUtil::loadDebug();
 		TwigUtil::loadMacros();
 
-		// set-up the dispatcher
-		$dispatcherInstance = Dispatcher::getInstance();
 		$dispatcherInstance->dispatch("twigLoader.customize");
 		$dispatcherInstance->dispatch("twigPatternLoader.customize");
 

src/PatternLab/PatternEngine/Twig/TwigUtil.php

@@ -19,7 +19,8 @@
 class TwigUtil {
 
 	protected static $instance = '';
-
+	protected static $loaders = array();
+
 	/**
 	* Get an instance of the Twig environment
 	*
@@ -46,7 +47,46 @@ public static function setInstance($instance = "") {
 		}
 
 		self::$instance = $instance;
-
+
+	}
+
+	/**
+	* Get an instance of the Twig loaders
+	*
+	* @return {Array}       List of Twig Loaders
+	*/
+	public static function getLoaders() {
+
+		if (empty(self::$loaders)) {
+			return false;
+		}
+
+		return self::$loaders;
+
+	}
+
+	/**
+	* Set an instance of the Twig loaders
+	* @param  {Array}       List of Twig Loaders
+	*/
+	public static function setLoaders($loaders = array()) {
+
+		if (empty($loaders)) {
+			Console::writeError("please set the loaders");
+		}
+
+		self::$loaders = $loaders;
+
+	}
+
+	/**
+	* Add a loader to the Twig Loaders array
+	* @param  {Loader}       A Twig Loader
+	*/
+	public static function addLoader($loader) {
+
+		self::$loaders[] = $loader;
+
 	}
 
 	/**