Fixes #3535: Syntax changes

docs/guide/tutorial-template-engines.md

@@ -24,6 +24,7 @@ component's behavior:
                     //'cachePath' => '@runtime/Twig/cache',
                     //'options' => [], /*  Array of twig options */
                     'globals' => ['html' => '\yii\helpers\Html'],
+                    'uses' => ['yii\bootstrap'],
                 ],
                 // ...
             ],
@@ -78,15 +79,70 @@ In case you don't need result you shoud use `void` wrapper:
 
 ```
 {{ void(my_function({'a' : 'b'})) }}
-{{ void(myObject.my_function({'a' : 'b'})} }}
+{{ void(myObject.my_function({'a' : 'b'})) }}
 ```
 
+#### Importing namespaces and classes
+
+You can import additional classes and namespaces right in the template:
+
+```
+Namespace import:
+{{ use('/app/widgets') }}
+
+Class import:
+{{ use('/yii/widgets/ActiveForm') }}
+
+Aliased class import:
+{{ use({'alias' => '/app/widgets/MyWidget'}) }}
+```
+
+#### Widgets
+
+Extension helps using widgets in convenient way converting their syntax to function calls:
+
+```
+{{ use('yii/bootstrap') }}
+{{ nav_bar_begin({
+    'brandLabel': 'My Company',
+}) }}
+    {{ nav_widget({
+        'options': {
+            'class': 'navbar-nav navbar-right',
+        },
+        'items': [{
+            'label': 'Home',
+            'url': '/site/index',
+        }]
+    }) }}
+{{ nav_bar_end() }}
+```
+
+In the template above `nav_bar_begin`, `nav_bar_end` or `nav_widget` consists of two parts. First part is widget name
+coverted to lowercase and underscores: `NavBar` becomes `nav_bar`, `Nav` becomes `nav`. `_begin`, `_end` and `_widget`
+are the same as `::begin()`, `::end()` and `::widget()` calls of a widget.
+
+One could also use more generic `widget_end()` that executes `Widget::end()`.
+
+#### Assets
+
+Assets could be registered the following way:
+
+```
+{{ use('yii/web/JqueryAsset') }}
+{{ register_jquery_asset() }}
+```
+
+In the call above `register` identifies that we're working with assets while `jquery_asset` translates to `JqueryAsset`
+class that we've already imported with `use`.
+
 #### Forms
 
-There are two form helper functions `form_begin` and `form_end` to make using forms more convenient:
+You can build forms the following way:
 
 ```
-{% set form = form_begin({
+{{ use('yii/widgets/ActiveForm') }}
+{% set form = active_form_begin({
     'id' : 'login-form',
     'options' : {'class' : 'form-horizontal'},
 }) %}
@@ -96,7 +152,7 @@ There are two form helper functions `form_begin` and `form_end` to make using fo
     <div class="form-group">
         <input type="submit" value="Login" class="btn btn-primary" />
     </div>
-{{ form_end() }}
+{{ active_form_end() }}
 ```
 
 

extensions/twig/CHANGELOG.md

@@ -8,6 +8,11 @@ Yii Framework 2 twig extension Change Log
 - Bug #3767: Fixed repeated adding of extensions when using config. One may now pass extension instances as well (grachov)
 - Bug #3877: Fixed `lexerOptions` throwing exception (dapatrese)
 - Enh #1799: Added `form_begin`, `form_end` to twig extension (samdark)
+- Chg #3535: Syntax changes:
+    - Removed `form_begin`, `form_end` (samdark)
+    - Added `use()` and `ViewRenderer::uses` that are importing classes and namespaces (grachov, samdark)
+    - Added widget dynamic functions `*_begin`, `*_end`, `*_widget`, `widget_end` (grachov, samdark)
+    - Added more tests (samdark)
 - Chg: Renamed `TwigSimpleFileLoader` into `FileLoader` (samdark)
 
 2.0.0-beta April 13, 2014

extensions/twig/Extension.php

@@ -0,0 +1,198 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\twig;
+
+use yii\base\InvalidCallException;
+use yii\helpers\Inflector;
+use yii\helpers\StringHelper;
+use yii\helpers\Url;
+
+/**
+ * Extension provides Yii-specific syntax for Twig templates.
+ *
+ * @author Andrey Grachov <[email protected]>
+ * @author Alexander Makarov <[email protected]>
+ */
+class Extension extends \Twig_Extension
+{
+    /**
+     * @var array used namespaces
+     */
+    protected $namespaces = [];
+
+    /**
+     * @var array used class aliases
+     */
+    protected $aliases = [];
+
+    /**
+     * @var array used widgets
+     */
+    protected $widgets = [];
+
+    /**
+     * Creates new instance
+     *
+     * @param array $uses namespaces and classes to use in the template
+     */
+    public function __construct(array $uses = [])
+    {
+        $this->addUses($uses);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getNodeVisitors()
+    {
+        return [
+            new Optimizer(),
+        ];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getFunctions()
+    {
+        $options = [
+            'is_safe' => ['html'],
+        ];
+        $functions = [
+            new \Twig_SimpleFunction('use', [$this, 'addUses'], $options),
+            new \Twig_SimpleFunction('*_begin', [$this, 'beginWidget'], $options),
+            new \Twig_SimpleFunction('*_end', [$this, 'endWidget'], $options),
+            new \Twig_SimpleFunction('widget_end', [$this, 'endWidget'], $options),
+            new \Twig_SimpleFunction('*_widget', [$this, 'widget'], $options),
+            new \Twig_SimpleFunction('path', [$this, 'path']),
+            new \Twig_SimpleFunction('url', [$this, 'url']),
+            new \Twig_SimpleFunction('void', function(){}),
+        ];
+
+        $options = array_merge($options, [
+            'needs_context' => true,
+        ]);
+        $functions[] = new \Twig_SimpleFunction('register_*', [$this, 'registerAsset'], $options);
+        foreach (['begin_page', 'end_page', 'begin_body', 'end_body', 'head'] as $helper) {
+            $functions[] = new \Twig_SimpleFunction($helper, [$this, 'viewHelper'], $options);
+        }
+        return $functions;
+    }
+
+    public function registerAsset($context, $asset)
+    {
+        return $this->resolveAndCall($asset, 'register', [
+            isset($context['this']) ? $context['this'] : null,
+        ]);
+    }
+
+    public function beginWidget($widget, $config = [])
+    {
+        $widget = $this->resolveClassName($widget);
+        $this->widgets[] = $widget;
+        return $this->call($widget, 'begin', [
+            $config,
+        ]);
+    }
+
+    public function endWidget($widget = null)
+    {
+        if ($widget === null) {
+            if (empty($this->widgets)) {
+                throw new InvalidCallException('Unexpected end_widget() call. A matching begin_widget() is not found.');
+            }
+            $this->call(array_pop($this->widgets), 'end');
+        } else {
+            array_pop($this->widgets);
+            $this->resolveAndCall($widget, 'end');
+        }
+    }
+
+    public function widget($widget, $config = [])
+    {
+        return $this->resolveAndCall($widget, 'widget', [
+            $config,
+        ]);
+    }
+
+    public function viewHelper($context, $name = null)
+    {
+        if ($name !== null && isset($context['this'])) {
+            $this->call($context['this'], Inflector::variablize($name));
+        }
+    }
+
+    public function resolveAndCall($className, $method, $arguments = null)
+    {
+        return $this->call($this->resolveClassName($className), $method, $arguments);
+    }
+
+    public function call($className, $method, $arguments = null)
+    {
+        $callable = [$className, $method];
+        if ($arguments === null) {
+            return call_user_func($callable);
+        } else {
+            return call_user_func_array($callable, $arguments);
+        }
+    }
+
+    public function resolveClassName($className)
+    {
+        $className = Inflector::id2camel($className, '_');
+        if (isset($this->aliases[$className])) {
+            return $this->aliases[$className];
+        }
+        $resolvedClassName = null;
+        foreach ($this->namespaces as $namespace) {
+            $resolvedClassName = $namespace . '\\' . $className;
+            if (class_exists($resolvedClassName)) {
+                return $this->aliases[$className] = $resolvedClassName;
+            }
+        }
+        return $className;
+    }
+
+    public function addUses($args)
+    {
+        foreach ((array)$args as $key => $value) {
+            $value = str_replace('/', '\\', $value);
+            if (is_int($key)) {
+                // namespace or class import
+                if (class_exists($value)) {
+                    // class import
+                    $this->aliases[StringHelper::basename($value)] = $value;
+                } else {
+                    // namespace
+                    $this->namespaces[] = $value;
+                }
+            } else {
+                // aliased class import
+                $this->aliases[$key] = $value;
+            }
+        }
+    }
+
+    public function path($path, $args = [])
+    {
+        return Url::to(array_merge([$path], $args));
+    }
+
+    public function url($path, $args = [])
+    {
+        return Url::to(array_merge([$path], $args), true);
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getName()
+    {
+        return 'yii2-twig';
+    }
+}

extensions/twig/Optimizer.php

@@ -0,0 +1,66 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\twig;
+
+/**
+ * Optimizer removes echo before special functions call and injects function name as an argument for the view helper
+ * calls.
+ *
+ * @author Andrey Grachov <[email protected]>
+ * @author Alexander Makarov <[email protected]>
+ */
+class Optimizer implements \Twig_NodeVisitorInterface
+{
+    /**
+     * @inheritdoc
+     */
+    public function enterNode(\Twig_NodeInterface $node, \Twig_Environment $env)
+    {
+        return $node;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function leaveNode(\Twig_NodeInterface $node, \Twig_Environment $env)
+    {
+        if ($node instanceof \Twig_Node_Print) {
+            $expression = $node->getNode('expr');
+            if ($expression instanceof \Twig_Node_Expression_Function) {
+                $name = $expression->getAttribute('name');
+                if (preg_match('/^(?:register_.+_asset|use|.+_begin|.+_end)$/', $name)) {
+                    return new \Twig_Node_Do($expression, $expression->getLine());
+                } elseif (in_array($name, ['begin_page', 'end_page', 'begin_body', 'end_body', 'head'])) {
+                    $arguments = [
+                        new \Twig_Node_Expression_Constant($name, $expression->getLine()),
+                    ];
+                    if ($expression->hasNode('arguments') && $expression->getNode('arguments') !== null) {
+                        foreach ($expression->getNode('arguments') as $key => $value) {
+                            if (is_int($key)) {
+                                $arguments[] = $value;
+                            } else {
+                                $arguments[$key] = $value;
+                            }
+                        }
+                    }
+                    $expression->setNode('arguments', new \Twig_Node($arguments));
+                    return new \Twig_Node_Do($expression, $expression->getLine());
+                }
+            }
+        }
+        return $node;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getPriority()
+    {
+        return 100;
+    }
+}