Pass a helper to section lambdas

src/Mustache/Compiler.php

@@ -118,8 +118,11 @@ class Mustache_Compiler
 
         class %s extends Mustache_Template
         {
+            private $lambdaHelper;
+
             public function renderInternal(Mustache_Context $context, $indent = \'\', $escape = false)
             {
+                $this->lambdaHelper = new Mustache_LambdaHelper($this->mustache, $context);
                 $buffer = \'\';
         %s
 
@@ -159,7 +162,7 @@ class Mustache_Compiler
             if (!is_string($value) && is_callable($value)) {
                 $source = %s;
                 $buffer .= $this->mustache
-                    ->loadLambda((string) call_user_func($value, $source)%s)
+                    ->loadLambda((string) call_user_func($value, $source, $this->lambdaHelper)%s)
                     ->renderInternal($context, $indent);
             } elseif (!empty($value)) {
                 $values = $this->isIterable($value) ? $value : array($value);

src/Mustache/LambdaHelper.php

@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of Mustache.php.
+ *
+ * (c) 2012 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Mustache Lambda Helper.
+ *
+ * Passed to section and interpolation lambdas, giving them access to a `render`
+ * method for rendering a string with the current context.
+ */
+class Mustache_LambdaHelper
+{
+    private $mustache;
+    private $context;
+
+    /**
+     * Mustache Lambda Helper constructor.
+     *
+     * @param Mustache_Engine  $mustache Mustache engine instance.
+     * @param Mustache_Context $context  Rendering context.
+     */
+    public function __construct(Mustache_Engine $mustache, Mustache_Context $context)
+    {
+        $this->mustache = $mustache;
+        $this->context  = $context;
+    }
+
+    /**
+     * Render a string as a Mustache template with the current rendering context.
+     *
+     * @param string $string
+     *
+     * @return Rendered template.
+     */
+    public function render($string)
+    {
+        return $this->mustache
+            ->loadLambda((string) $string)
+            ->renderInternal($this->context);
+    }
+}

test/Mustache/Test/FiveThree/Functional/LambdaHelperTest.php

@@ -0,0 +1,37 @@
+<?php
+
+/*
+ * This file is part of Mustache.php.
+ *
+ * (c) 2012 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * @group lambdas
+ * @group functional
+ */
+class Mustache_Test_FiveThree_Functional_LambdaHelperTest extends PHPUnit_Framework_TestCase {
+
+    private $mustache;
+
+    public function setUp() {
+        $this->mustache = new Mustache_Engine;
+    }
+
+    public function testSectionLambdaHelper() {
+        $one = $this->mustache->loadTemplate('{{name}}');
+        $two = $this->mustache->loadTemplate('{{#lambda}}{{name}}{{/lambda}}');
+
+        $foo = new StdClass;
+        $foo->name = 'Mario';
+        $foo->lambda = function($text, $mustache) {
+            return strtoupper($mustache->render($text));
+        };
+
+        $this->assertEquals('Mario', $one->render($foo));
+        $this->assertEquals('MARIO', $two->render($foo));
+    }
+}