Added {% try %} ... {% catch %} Error: {{ e.message }} {% endcatch %} tag to allow basic exception handling inside Twig

CHANGELOG.md

@@ -7,6 +7,7 @@
     * Added `Grav\Framework\Object` classes for creating collections of objects
     * Added `Grav\Framework\Page` interfaces
     * Added `|nicenumber` Twig filter
+    * Added `{% try %} ... {% catch %} Error: {{ e.message }} {% endcatch %}` tag to allow basic exception handling inside Twig
     * Deprecated GravTrait
 1. [](#improved)
     * Make it possible to include debug bar also into non-HTML responses

system/src/Grav/Common/Debugger.php

@@ -74,7 +74,7 @@ class Debugger
      */
     public function enabled($state = null)
     {
-        if (isset($state)) {
+        if ($state !== null) {
             $this->enabled = $state;
         }
 
@@ -92,7 +92,7 @@ class Debugger
 
             // Only add assets if Page is HTML
             $page = $this->grav['page'];
-            if ($page->templateFormat() != 'html') {
+            if ($page->templateFormat() !== 'html') {
                 return $this;
             }
 
@@ -107,13 +107,13 @@ class Debugger
 
             // Get the required CSS files
             list($css_files, $js_files) = $this->renderer->getAssets(null, JavascriptRenderer::RELATIVE_URL);
-            foreach ($css_files as $css) {
+            foreach ((array)$css_files as $css) {
                 $assets->addCss($css);
             }
 
             $assets->addCss('/system/assets/debugger.css');
 
-            foreach ($js_files as $js) {
+            foreach ((array)$js_files as $js) {
                 $assets->addJs($js);
             }
         }
@@ -166,7 +166,7 @@ class Debugger
         if ($this->enabled()) {
             // Only add assets if Page is HTML
             $page = $this->grav['page'];
-            if ($page->templateFormat() != 'html' || !$this->renderer) {
+            if (!$this->renderer || $page->templateFormat() !== 'html') {
                 return $this;
             }
 
@@ -216,7 +216,7 @@ class Debugger
      */
     public function startTimer($name, $description = null)
     {
-        if ($name[0] == '_' || $this->enabled()) {
+        if ($name[0] === '_' || $this->enabled()) {
             $this->debugbar['time']->startMeasure($name, $description);
             $this->timers[] = $name;
         }
@@ -233,7 +233,7 @@ class Debugger
      */
     public function stopTimer($name)
     {
-        if (in_array($name, $this->timers) && ($name[0] == '_' || $this->enabled())) {
+        if (in_array($name, $this->timers, true) && ($name[0] === '_' || $this->enabled())) {
             $this->debugbar['time']->stopMeasure($name);
         }
 

system/src/Grav/Common/Twig/TokenParserTry.php

@@ -0,0 +1,66 @@
+<?php
+/**
+ * @package    Grav.Common.Twig
+ *
+ * @copyright  Copyright (C) 2014 - 2017 RocketTheme, LLC. All rights reserved.
+ * @license    MIT License; see LICENSE file for details.
+ */
+
+namespace Grav\Common\Twig;
+
+/**
+ * Handles try/catch in template file.
+ *
+ * <pre>
+ * {% try %}
+ *    <li>{{ user.get('name') }}</li>
+ * {% catch %}
+ *    {{ e.message }}
+ * {% endcatch %}
+ * </pre>
+ */
+class TokenParserTry extends \Twig_TokenParser
+{
+    /**
+     * Parses a token and returns a node.
+     *
+     * @param \Twig_Token $token A Twig_Token instance
+     *
+     * @return \Twig_NodeInterface A Twig_NodeInterface instance
+     */
+    public function parse(\Twig_Token $token)
+    {
+        $lineno = $token->getLine();
+        $stream = $this->parser->getStream();
+
+        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+        $try = $this->parser->subparse([$this, 'decideCatch']);
+        $stream->next();
+        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+        $catch = $this->parser->subparse([$this, 'decideEnd']);
+        $stream->next();
+        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+
+        return new TwigNodeTry($try, $catch, $lineno, $this->getTag());
+    }
+
+    public function decideCatch(\Twig_Token $token)
+    {
+        return $token->test(array('catch'));
+    }
+
+    public function decideEnd(\Twig_Token $token)
+    {
+        return $token->test(array('endtry')) || $token->test(array('endcatch'));
+    }
+
+    /**
+     * Gets the tag name associated with this token parser.
+     *
+     * @return string The tag name
+     */
+    public function getTag()
+    {
+        return 'try';
+    }
+}

system/src/Grav/Common/Twig/TwigExtension.php

@@ -148,6 +148,16 @@ class TwigExtension extends \Twig_Extension
         ];
     }
 
+    /**
+     * @return array
+     */
+    public function getTokenParsers()
+    {
+        return [
+            new TokenParserTry(),
+        ];
+    }
+
     /**
      * Filters field name by changing dot notation into array notation.
      *

system/src/Grav/Common/Twig/TwigNodeTry.php

@@ -0,0 +1,52 @@
+<?php
+/**
+ * @package    Grav.Common.Twig
+ *
+ * @copyright  Copyright (C) 2014 - 2017 RocketTheme, LLC. All rights reserved.
+ * @license    MIT License; see LICENSE file for details.
+ */
+
+namespace Grav\Common\Twig;
+
+class TwigNodeTry extends \Twig_Node
+{
+    public function __construct(\Twig_NodeInterface $try, \Twig_NodeInterface $catch = null, $lineno, $tag = null)
+    {
+        parent::__construct(array('try' => $try, 'catch' => $catch), array(), $lineno, $tag);
+    }
+
+    /**
+     * Compiles the node to PHP.
+     *
+     * @param \Twig_Compiler $compiler A Twig_Compiler instance
+     * @throws \LogicException
+     */
+    public function compile(\Twig_Compiler $compiler)
+    {
+        $compiler->addDebugInfo($this);
+
+        $compiler
+            ->write('try {')
+        ;
+
+        $compiler
+            ->indent()
+            ->subcompile($this->getNode('try'))
+        ;
+
+        if ($this->hasNode('catch') && null !== $this->getNode('catch')) {
+            $compiler
+                ->outdent()
+                ->write('} catch (\Exception $e) {' . "\n")
+                ->indent()
+                ->write('if (isset($context[\'grav\'][\'debugger\'])) $context[\'grav\'][\'debugger\']->addException($e);' . "\n")
+                ->write('$context[\'e\'] = $e;' . "\n")
+                ->subcompile($this->getNode('catch'))
+            ;
+        }
+
+        $compiler
+            ->outdent()
+            ->write("}\n");
+    }
+}