[feature/twig] Changing method for begin node to not use anonymous function

The way it was setup would actually require PHP 5.4, which isn't an option
right now. Leaving the old code there, just commented out, for now at least.

PHPBB3-11598

phpBB/includes/template/twig/environment.php

@@ -0,0 +1,40 @@
+<?php
+/**
+*
+* @package phpBB3
+* @copyright (c) 2013 phpBB Group
+* @license http://opensource.org/licenses/gpl-2.0.php GNU General Public License v2
+*
+*/
+
+/**
+* @ignore
+*/
+if (!defined('IN_PHPBB'))
+{
+	exit;
+}
+
+class phpbb_template_twig_environment extends Twig_Environment
+{
+	/**
+	* recursive helper to set variables into $context so that Twig can properly fetch them for display
+	*
+	* @param array $data Data to set at the end of the chain
+	* @param array $blocks Array of blocks to loop into still
+	* @param mixed $current_location Current location in $context (recursive!)
+	*/
+	public function context_recursive_loop_builder($data, $blocks, &$current_location)
+	{
+		$block = array_shift($blocks);
+
+		if (empty($blocks))
+		{
+			$current_location[$block] = $data;
+		}
+		else
+		{
+			$this->context_recursive_loop_builder($data, $blocks, $current_location[$block]);
+		}
+	}
+}

phpBB/includes/template/twig/node/begin.php

@@ -29,6 +29,49 @@ class phpbb_template_twig_node_begin extends Twig_Node
      * @param Twig_Compiler A Twig_Compiler instance
      */
     public function compile(Twig_Compiler $compiler)
+    {
+		$compiler
+			->write("if (!isset(\$phpbb_blocks)) {\n")
+			->indent()
+				->write("\$phpbb_blocks = array();\n")
+				->write("\$parent = \$context['_phpbb_blocks'];\n")
+			->outdent()
+			->write("}\n")
+			->write("\$phpbb_blocks[] = '" . $this->getAttribute('beginName') . "';\n")
+		;
+
+        $compiler
+			->write("foreach (\$parent['" . $this->getAttribute('beginName') . "'] as \$" . $this->getAttribute('beginName') . ") {\n")
+			->indent()
+				// Set up $context correctly so that Twig can get the correct data with $this->getAttribute
+				->write("\$this->getEnvironment()->context_recursive_loop_builder(\$" . $this->getAttribute('beginName') . ", \$phpbb_blocks, \$context);\n")
+
+				// We store the parent so that we can do this recursively
+				->write("\$parent = \$" . $this->getAttribute('beginName') . ";\n")
+        ;
+
+        $compiler->subcompile($this->getNode('body'));
+
+        $compiler
+            ->outdent()
+            ->write("}\n")
+
+            // Remove the last item from the blocks storage as we've completed iterating over them all
+            ->write("array_pop(\$phpbb_blocks);\n")
+
+            // If we've gone through all of the blocks, we're back at the main level and have completed, so unset the var
+            ->write("if (empty(\$phpbb_blocks)) { unset(\$phpbb_blocks); }\n")
+        ;
+    }
+
+    /**
+     * Compiles the node to PHP.
+     *
+     * Uses anonymous functions to compile the loops, which seems nicer to me, but requires PHP 5.4 (since subcompile uses $this, which is not available in 5.3)
+     *
+     * @param Twig_Compiler A Twig_Compiler instance
+     *
+    public function compile(Twig_Compiler $compiler)
     {
         $compiler->addDebugInfo($this);
 
@@ -85,4 +128,5 @@ class phpbb_template_twig_node_begin extends Twig_Node
 			->outdent()
 			->write("}\n");
     }
+    */
 }

phpBB/includes/template/twig/twig.php

@@ -118,7 +118,7 @@ class phpbb_template_twig implements phpbb_template
 		// @todo use phpbb_admin path
 		$loader->addPath($this->phpbb_root_path . 'adm/style/', 'admin');
 
-		$this->twig = new Twig_Environment($loader, array(
+		$this->twig = new phpbb_template_twig_environment($loader, array(
 		    'cache'			=> $this->cachepath,
 		    'debug'			=> true, // @todo
 		    'auto_reload'	=> true, // @todo
@@ -422,11 +422,13 @@ class phpbb_template_twig implements phpbb_template
 		$vars = array_merge(
 			$vars,
 			$this->context->get_rootref(),
-			$this->context->get_tpldata()
+			array(
+				'_phpbb_blocks'	=>  $this->context->get_tpldata(),
+			)
 		);
 
 		// cleanup
-		unset($vars['.']);
+		unset($vars['_phpbb_blocks']['.']);
 
 		return $vars;
 	}