Smarty: added path function and exposed $app and $this

docs/view_renderers.md

@@ -65,3 +65,18 @@ or `$this->renderPartial()` from your controller:
 ```php
 echo $this->render('renderer.tpl', array('username' => 'Alex'));
 ```
+
+### Additional functions
+
+Additionally to regular Smarty syntax the following is available in Yii:
+
+```php
+<a href="{path route='blog/view' alias=$post.alias}">{$post.title}</a>
+```
+
+path function calls `Html::url()` internally.
+
+### Additional variables
+
+- `$app` = `\Yii::$app`
+- `$this` = current `View` object

framework/renderers/SmartyViewRenderer.php

@@ -13,6 +13,7 @@ use Yii;
 use Smarty;
 use yii\base\View;
 use yii\base\ViewRenderer;
+use yii\helpers\Html;
 
 /**
  * SmartyViewRenderer allows you to use Smarty templates in views.
@@ -48,6 +49,34 @@ class SmartyViewRenderer extends ViewRenderer
 		$this->smarty = new Smarty();
 		$this->smarty->setCompileDir(Yii::getAlias($this->compilePath));
 		$this->smarty->setCacheDir(Yii::getAlias($this->cachePath));
+
+		$this->smarty->registerPlugin('function', 'path', array($this, 'smarty_function_path'));
+	}
+
+	/**
+	 * Smarty template function to get a path for using in links
+	 *
+	 * Usage is the following:
+	 *
+	 * {path route='blog/view' alias=$post.alias user=$user.id}
+	 *
+	 * where route is Yii route and the rest of parameters are passed as is.
+	 *
+	 * @param $params
+	 * @param \Smarty_Internal_Template $template
+	 *
+	 * @return string
+	 */
+	public function smarty_function_path($params, \Smarty_Internal_Template $template)
+	{
+		if(!isset($params['route'])) {
+			trigger_error("path: missing 'route' parameter");
+		}
+
+		array_unshift($params, $params['route']) ;
+		unset($params['route']);
+
+		return Html::url($params);
 	}
 
 	/**
@@ -67,6 +96,10 @@ class SmartyViewRenderer extends ViewRenderer
 		$ext = pathinfo($file, PATHINFO_EXTENSION);
 		/** @var \Smarty_Internal_Template $template */
 		$template = $this->smarty->createTemplate($file, null, null, $params, true);
+
+		$template->assign('app', \Yii::$app);
+		$template->assign('this', $view);
+
 		return $template->fetch();
 	}
 }