Issue #323 dynamic property assignment

doc/content/engine/extensions.md

@@ -16,12 +16,19 @@ use League\Plates\Extension\ExtensionInterface;
 
 class ChangeCase implements ExtensionInterface
 {
-    public function register(Engine $engine)
+    protected ?Template $template;
+
+    public function register(Engine $engine): void
     {
         $engine->registerFunction('uppercase', [$this, 'uppercaseString']);
         $engine->registerFunction('lowercase', [$this, 'lowercaseString']);
     }
 
+    public function setTemplate(?Template $template): void
+    {
+        $this->template = $template;
+    }
+
     public function uppercaseString($var)
     {
         return strtoupper($var);
@@ -56,11 +63,18 @@ use League\Plates\Extension\ExtensionInterface;
 
 class ChangeCase implements ExtensionInterface
 {
-    public function register(Engine $engine)
+    protected ?Template $template;
+
+    public function register(Engine $engine): void
     {
         $engine->registerFunction('case', [$this, 'getObject']);
     }
 
+    public function setTemplate(?Template $template): void
+    {
+        $this->template = $template;
+    }
+
     public function getObject()
     {
         return $this;
@@ -94,7 +108,7 @@ $engine->loadExtension(new ChangeCase());
 
 ## Accessing the engine and template
 
-It may be desirable to access the `engine` or `template` objects from within your extension. Plates makes both of these objects available to you. The engine is automatically passed to the `register()` method, and the template is assigned as a parameter on each function call.
+It may be desirable to access the `engine` or `template` objects from within your extension. Plates makes both of these objects available to you. The engine is automatically passed to the `register()` method, and the template is assigned with a call to `setTemplate()` with the according template when available.
 
 ~~~ php
 use League\Plates\Engine;
@@ -103,7 +117,7 @@ use League\Plates\Extension\ExtensionInterface;
 class MyExtension implements ExtensionInterface
 {
     protected $engine;
-    public $template; // must be public
+    protected $template;
 
     public function register(Engine $engine)
     {
@@ -115,5 +129,10 @@ class MyExtension implements ExtensionInterface
         // Register functions
         // ...
     }
+
+    public function setTemplate(?Template $template): void
+    {
+        $this->template = $template;
+    }
 }
 ~~~

src/Extension/Asset.php

@@ -12,10 +12,9 @@
 class Asset implements ExtensionInterface
 {
     /**
-     * Instance of the current template.
-     * @var Template
+     * @var Template|null
      */
-    public $template;
+    protected ?Template $template;
 
     /**
      * Path to asset directory.
@@ -43,13 +42,22 @@ public function __construct($path, $filenameMethod = false)
     /**
      * Register extension function.
      * @param Engine $engine
-     * @return null
+     * @return void
      */
-    public function register(Engine $engine)
+    public function register(Engine $engine): void
     {
         $engine->registerFunction('asset', array($this, 'cachedAssetUrl'));
     }
 
+    /**
+     * @param Template|null $template
+     * @return void
+     */
+    public function setTemplate(?Template $template): void
+    {
+        $this->template = $template;
+    }
+
     /**
      * Create "cache busted" asset URL.
      * @param  string $url

src/Extension/ExtensionInterface.php

@@ -3,11 +3,13 @@
 namespace League\Plates\Extension;
 
 use League\Plates\Engine;
+use League\Plates\Template\Template;
 
 /**
  * A common interface for extensions.
  */
 interface ExtensionInterface
 {
-    public function register(Engine $engine);
+    public function register(Engine $engine): void;
+    public function setTemplate(?Template $template): void;
 }

src/Extension/URI.php

@@ -12,10 +12,9 @@
 class URI implements ExtensionInterface
 {
     /**
-     * Instance of the current template.
-     * @var Template
+     * @var Template|null
      */
-    public $template;
+    protected ?Template $template;
 
     /**
      * The request URI.
@@ -42,13 +41,22 @@ public function __construct($uri)
     /**
      * Register extension functions.
      * @param Engine $engine
-     * @return null
+     * @return void
      */
-    public function register(Engine $engine)
+    public function register(Engine $engine): void
     {
         $engine->registerFunction('uri', array($this, 'runUri'));
     }
 
+    /**
+     * @param Template|null $template
+     * @return void
+     */
+    public function setTemplate(?Template $template): void
+    {
+        $this->template = $template;
+    }
+
     /**
      * Perform URI check.
      * @param  null|integer|string $var1

src/Template/Func.php

@@ -95,11 +95,13 @@ public function getCallback()
      */
     public function call(Template $template = null, $arguments = array())
     {
-        if (is_array($this->callback) and
-            isset($this->callback[0]) and
-            $this->callback[0] instanceof ExtensionInterface
-        ) {
-            $this->callback[0]->template = $template;
+        if ($template) {
+            if (is_array($this->callback) and
+                isset($this->callback[0]) and
+                $this->callback[0] instanceof ExtensionInterface
+            ) {
+                $this->callback[0]->setTemplate($template);
+            }
         }
 
         return call_user_func_array($this->callback, $arguments);

tests/Template/FuncTest.php

@@ -7,6 +7,7 @@
 use League\Plates\Engine;
 use League\Plates\Extension\ExtensionInterface;
 use League\Plates\Template\Func;
+use League\Plates\Template\Template;
 use PHPUnit\Framework\TestCase;
 
 class FuncTest extends TestCase
@@ -59,9 +60,24 @@ public function testFunctionCall()
     public function testExtensionFunctionCall()
     {
         $extension = new class() implements ExtensionInterface {
-            public function register(Engine $engine)
+            protected ?Template $template;
+
+            /**
+             * Do nothing
+             */
+            public function register(Engine $engine): void
             {
             }
+
+            /**
+             * @param Template|null $template
+             * @return void
+             */
+            public function setTemplate(?Template $template): void
+            {
+                $this->template = $template;
+            }
+
             public function foo(): string
             {
                 return 'bar';