Added {% switch %} twig tag

CHANGELOG.md

@@ -7,6 +7,7 @@
     * Added `$grav['uri]->getCurrentUri()` method to get `Grav\Framework\Uri\Uri` instance for the current URL
     * Added `$grav['uri]->getCurrentRoute()` method to get `Grav\Framework\Route\Route` instance for the current URL
     * Added ability to have `php` version dependencies in GPM assets
+    * Added new `{% switch %}` twig tag for more elegant if statements
     * Added new `{% markdown %}` twig tag
 1. [](#improved)
     * Vendor library updated to latest  

system/src/Grav/Common/Twig/Node/TwigNodeSwitch.php

@@ -0,0 +1,71 @@
+<?php
+/**
+ * @package    Grav.Common.Twig
+ *
+ * @copyright  Copyright (C) 2015 - 2018 Trilby Media, LLC. All rights reserved.
+ * @license    MIT License; see LICENSE file for details.
+ */
+
+namespace Grav\Common\Twig\Node;
+
+class TwigNodeSwitch extends \Twig_Node implements \Twig_NodeOutputInterface
+{
+    public function __construct(\Twig_NodeInterface $value, \Twig_NodeInterface $cases, \Twig_NodeInterface $default = null, $lineno, $tag = null)
+    {
+        parent::__construct(array('value' => $value, 'cases' => $cases, 'default' => $default), array(), $lineno, $tag);
+    }
+
+    /**
+     * Compiles the node to PHP.
+     *
+     * @param \Twig_Compiler A Twig_Compiler instance
+     */
+    public function compile(\Twig_Compiler $compiler)
+    {
+        $compiler
+            ->addDebugInfo($this)
+            ->write("switch (")
+            ->subcompile($this->getNode('value'))
+            ->raw(") {\n")
+            ->indent();
+
+        foreach ($this->getNode('cases') as $case)
+        {
+            if (!$case->hasNode('body'))
+            {
+                continue;
+            }
+
+            foreach ($case->getNode('values') as $value)
+            {
+                $compiler
+                    ->write('case ')
+                    ->subcompile($value)
+                    ->raw(":\n");
+            }
+
+            $compiler
+                ->write("{\n")
+                ->indent()
+                ->subcompile($case->getNode('body'))
+                ->write("break;\n")
+                ->outdent()
+                ->write("}\n");
+        }
+
+        if ($this->hasNode('default') && $this->getNode('default') !== null)
+        {
+            $compiler
+                ->write("default:\n")
+                ->write("{\n")
+                ->indent()
+                ->subcompile($this->getNode('default'))
+                ->outdent()
+                ->write("}\n");
+        }
+
+        $compiler
+            ->outdent()
+            ->write("}\n");
+    }
+}

system/src/Grav/Common/Twig/TokenParser/TwigTokenParserSwitch.php

@@ -0,0 +1,138 @@
+<?php
+/**
+ * @package    Grav.Common.Twig
+ *
+ * @copyright  Copyright (C) 2015 - 2018 Trilby Media, LLC. All rights reserved.
+ * @license    MIT License; see LICENSE file for details.
+ * @origin     https://gist.github.com/maxgalbu/9409182
+ */
+
+namespace Grav\Common\Twig\TokenParser;
+
+use Grav\Common\Twig\Node\TwigNodeSwitch;
+
+/**
+ * Adds ability use elegant switch instead of ungainly if statements
+ *
+ * {% switch type %}
+ *   {% case 'foo' %}
+ *      {{ my_data.foo }}
+ *   {% case 'bar' %}
+ *      {{ my_data.bar }}
+ *   {% default %}
+ *      {{ my_data.default }}
+ * {% endswitch %}
+ */
+class TwigTokenParserSwitch extends \Twig_TokenParser
+{
+    /**
+     * {@inheritdoc}
+     */
+    public function parse(\Twig_Token $token)
+    {
+        $lineno = $token->getLine();
+        $stream = $this->parser->getStream();
+
+        $name = $this->parser->getExpressionParser()->parseExpression();
+        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+
+        // There can be some whitespace between the {% switch %} and first {% case %} tag.
+        while ($stream->getCurrent()->getType() == \Twig_Token::TEXT_TYPE && trim($stream->getCurrent()->getValue()) == '')
+        {
+            $stream->next();
+        }
+
+        $stream->expect(\Twig_Token::BLOCK_START_TYPE);
+
+        $expressionParser = $this->parser->getExpressionParser();
+
+        $default = null;
+        $cases = array();
+        $end = false;
+
+        while (!$end)
+        {
+            $next = $stream->next();
+
+            switch ($next->getValue())
+            {
+                case 'case':
+                    {
+                        $values = array();
+
+                        while (true)
+                        {
+                            $values[] = $expressionParser->parsePrimaryExpression();
+                            // Multiple allowed values?
+                            if ($stream->test(\Twig_Token::OPERATOR_TYPE, 'or'))
+                            {
+                                $stream->next();
+                            }
+                            else
+                            {
+                                break;
+                            }
+                        }
+
+                        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+                        $body = $this->parser->subparse(array($this, 'decideIfFork'));
+                        $cases[] = new \Twig_Node(array(
+                            'values' => new \Twig_Node($values),
+                            'body' => $body
+                        ));
+                        break;
+                    }
+                case 'default':
+                    {
+                        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+                        $default = $this->parser->subparse(array($this, 'decideIfEnd'));
+                        break;
+                    }
+                case 'endswitch':
+                    {
+                        $end = true;
+                        break;
+                    }
+                default:
+                    {
+                        throw new \Twig_Error_Syntax(sprintf('Unexpected end of template. Twig was looking for the following tags "case", "default", or "endswitch" to close the "switch" block started at line %d)', $lineno), -1);
+                    }
+            }
+        }
+
+        $stream->expect(\Twig_Token::BLOCK_END_TYPE);
+
+        return new TwigNodeSwitch($name, new \Twig_Node($cases), $default, $lineno, $this->getTag());
+    }
+
+    /**
+     * Decide if current token marks switch logic.
+     *
+     * @param \Twig_Token $token
+     * @return bool
+     */
+    public function decideIfFork(\Twig_Token $token)
+    {
+        return $token->test(array('case', 'default', 'endswitch'));
+    }
+
+    /**
+     * Decide if current token marks end of swtich block.
+     *
+     * @param \Twig_Token $token
+     * @return bool
+     */
+    public function decideIfEnd(\Twig_Token $token)
+    {
+        return $token->test(array('endswitch'));
+    }
+
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getTag()
+    {
+        return 'switch';
+    }
+}

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

@@ -13,6 +13,7 @@
 use Grav\Common\Page\Media;
 use Grav\Common\Twig\TokenParser\TwigTokenParserScript;
 use Grav\Common\Twig\TokenParser\TwigTokenParserStyle;
+use Grav\Common\Twig\TokenParser\TwigTokenParserSwitch;
 use Grav\Common\Twig\TokenParser\TwigTokenParserTryCatch;
 use Grav\Common\Twig\TokenParser\TwigTokenParserMarkdown;
 use Grav\Common\Utils;
@@ -158,6 +159,7 @@ public function getTokenParsers()
             new TwigTokenParserScript(),
             new TwigTokenParserStyle(),
             new TwigTokenParserMarkdown(),
+            new TwigTokenParserSwitch(),
         ];
     }