added with tag

doc/tags/index.rst

@@ -22,3 +22,4 @@ Tags
     spaceless
     use
     verbatim
+    with

doc/tags/with.rst

@@ -0,0 +1,42 @@
+``with``
+========
+
+.. versionadded:: 1.28
+    The ``with`` tag was added in Twig 1.28.
+
+Use the ``with`` tag to create a new inner scope. Variables set within this
+scope are not visible outside of the scope:
+
+.. code-block:: jinja
+
+    {% with %}
+        {% set foo = 42 %}
+        {{ foo }}           foo is 42 here
+    {% endwith %}
+    foo is not visible here any longer
+
+Instead of defining variables at the beginning of the scope, you can pass a
+hash of variables you want to define in the ``with`` tag; the previous example
+is equivalent to the following one:
+
+.. code-block:: jinja
+
+    {% with { foo: 42 } %}
+        {{ foo }}           foo is 42 here
+    {% endwith %}
+    foo is not visible here any longer
+
+    {# it works with any expression that resolves to a hash #}
+    {% set vars = { foo: 42 } %}
+    {% with vars %}
+        ...
+    {% endwith %}
+
+By default, the inner scope has access to the outer scope context; you can
+disable this behavior by appending the ``only`` keyword:
+
+    {% set bar = 'bar' %}
+    {% with { foo: 42 } only %}
+        {# only foo is defined #}
+        {# bar is not defined #}
+    {% endwith %}

lib/Twig/Extension/Core.php

@@ -132,6 +132,7 @@ class Twig_Extension_Core extends Twig_Extension
             new Twig_TokenParser_Flush(),
             new Twig_TokenParser_Do(),
             new Twig_TokenParser_Embed(),
+            new Twig_TokenParser_With(),
         );
     }
 

lib/Twig/Node/With.php

@@ -0,0 +1,62 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) 2016 Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Represents a nested "with" scope.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class Twig_Node_With extends Twig_Node
+{
+    public function __construct(Twig_Node $body, Twig_Node $variables = null, $only = false, $lineno, $tag = null)
+    {
+        $nodes = array('body' => $body);
+        if (null !== $variables) {
+            $nodes['variables'] = $variables;
+        }
+
+        parent::__construct($nodes, array('only' => (bool) $only), $lineno, $tag);
+    }
+
+    public function compile(Twig_Compiler $compiler)
+    {
+        $compiler->addDebugInfo($this);
+
+        if ($this->hasNode('variables')) {
+            $varsName = $compiler->getVarName();
+            $compiler
+                ->write(sprintf('$%s = ', $varsName))
+                ->subcompile($this->getNode('variables'))
+                ->raw(";\n")
+                ->write(sprintf("if (!is_array(\$%s)) {\n", $varsName))
+                ->indent()
+                ->write("throw new Twig_Error_Runtime('Variables passed to the \"with\" tag must be a hash.');\n")
+                ->outdent()
+                ->write("}\n")
+            ;
+
+            if ($this->getAttribute('only')) {
+                $compiler->write("\$context = array('_parent' => \$context);\n");
+            } else {
+                $compiler->write("\$context['_parent'] = \$context;\n");
+            }
+
+            $compiler->write(sprintf("\$context = array_merge(\$context, \$%s);\n", $varsName));
+        } else {
+            $compiler->write("\$context['_parent'] = \$context;\n");
+        }
+
+        $compiler
+            ->subcompile($this->getNode('body'))
+            ->write("\$context = \$context['_parent'];\n")
+        ;
+    }
+}

lib/Twig/TokenParser/With.php

@@ -0,0 +1,48 @@
+<?php
+
+/*
+ * This file is part of Twig.
+ *
+ * (c) 2016 Fabien Potencier
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+/**
+ * Creates a nested scope.
+ *
+ * @author Fabien Potencier <fabien@symfony.com>
+ */
+class Twig_TokenParser_With extends Twig_TokenParser
+{
+    public function parse(Twig_Token $token)
+    {
+        $stream = $this->parser->getStream();
+
+        $variables = null;
+        $only = false;
+        if (!$stream->test(Twig_Token::BLOCK_END_TYPE)) {
+            $variables = $this->parser->getExpressionParser()->parseExpression();
+            $only = $stream->nextIf(Twig_Token::NAME_TYPE, 'only');
+        }
+
+        $stream->expect(Twig_Token::BLOCK_END_TYPE);
+
+        $body = $this->parser->subparse(array($this, 'decideWithEnd'), true);
+
+        $stream->expect(Twig_Token::BLOCK_END_TYPE);
+
+        return new Twig_Node_With($body, $variables, $only, $token->getLine(), $this->getTag());
+    }
+
+    public function decideWithEnd(Twig_Token $token)
+    {
+        return $token->test('endwith');
+    }
+
+    public function getTag()
+    {
+        return 'with';
+    }
+}

test/Twig/Tests/Fixtures/tags/with/basic.test

@@ -0,0 +1,13 @@
+--TEST--
+"with" tag
+--TEMPLATE--
+{% with %}
+    {% set bar = 'BAZ' %}
+    {{ foo }}{{ bar }}
+{% endwith %}
+{{ foo }}{{ bar }}
+--DATA--
+return array('foo' => 'foo', 'bar' => 'bar')
+--EXPECT--
+fooBAZ
+foobar

test/Twig/Tests/Fixtures/tags/with/expression.test

@@ -0,0 +1,10 @@
+--TEST--
+"with" tag with expression
+--TEMPLATE--
+{% with {foo: 'foo', bar: 'BAZ'} %}
+    {{ foo }}{{ bar }}
+{% endwith %}
+--DATA--
+return array('foo' => 'baz')
+--EXPECT--
+fooBAZ

test/Twig/Tests/Fixtures/tags/with/nested.test

@@ -0,0 +1,15 @@
+--TEST--
+nested "with" tags
+--TEMPLATE--
+{% set foo, bar = 'foo', 'bar' %}
+{% with {bar: 'BAZ'} %}
+    {% with {foo: 'FOO'} %}
+        {{ foo }}{{ bar }}
+    {% endwith %}
+{% endwith %}
+{{ foo }}{{ bar }}
+--DATA--
+return array()
+--EXPECT--
+FOOBAZ
+    foobar

test/Twig/Tests/Fixtures/tags/with/with_no_hash.test

@@ -0,0 +1,10 @@
+--TEST--
+"with" tag with an expression that is not a hash
+--TEMPLATE--
+{% with vars %}
+    {{ foo }}{{ bar }}
+{% endwith %}
+--DATA--
+return array('vars' => 'no-hash')
+--EXCEPTION--
+Twig_Error_Runtime: Variables passed to the "with" tag must be a hash in "index.twig" at line 2.

test/Twig/Tests/Fixtures/tags/with/with_only.test

@@ -0,0 +1,10 @@
+--TEST--
+"with" tag with expression and only
+--TEMPLATE--
+{% with {foo: 'foo', bar: 'BAZ'} only %}
+    {{ foo }}{{ bar }}{{ baz }}
+{% endwith %}
+--DATA--
+return array('foo' => 'baz', 'baz' => 'baz')
+--EXCEPTION--
+Twig_Error_Runtime: Variable "baz" does not exist in "index.twig" at line 3.