Added twig tag for links: {% link icon 'theme://images/favicon.png' priority: 20 with { type: 'image/png' } %}

CHANGELOG.md

@@ -4,6 +4,7 @@
 1. [](#new)
     * Added links and modules support to `HtmlBlock` class
     * Added module support for twig script tag: `{% script module 'theme://js/module.mjs' %}`
+    * Added twig tag for links: `{% link icon 'theme://images/favicon.png' priority: 20 with { type: 'image/png' } %}`
 
 # v1.7.27.1
 ## 01/12/2022

system/src/Grav/Common/Twig/Extension/GravExtension.php

@@ -22,6 +22,7 @@ use Grav\Common\Page\Media;
 use Grav\Common\Scheduler\Cron;
 use Grav\Common\Security;
 use Grav\Common\Twig\TokenParser\TwigTokenParserCache;
+use Grav\Common\Twig\TokenParser\TwigTokenParserLink;
 use Grav\Common\Twig\TokenParser\TwigTokenParserRender;
 use Grav\Common\Twig\TokenParser\TwigTokenParserScript;
 use Grav\Common\Twig\TokenParser\TwigTokenParserStyle;
@@ -252,6 +253,7 @@ class GravExtension extends AbstractExtension implements GlobalsInterface
             new TwigTokenParserTryCatch(),
             new TwigTokenParserScript(),
             new TwigTokenParserStyle(),
+            new TwigTokenParserLink(),
             new TwigTokenParserMarkdown(),
             new TwigTokenParserSwitch(),
             new TwigTokenParserCache(),

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

@@ -0,0 +1,98 @@
+<?php
+
+/**
+ * @package    Grav\Common\Twig
+ *
+ * @copyright  Copyright (c) 2015 - 2022 Trilby Media, LLC. All rights reserved.
+ * @license    MIT License; see LICENSE file for details.
+ */
+
+namespace Grav\Common\Twig\Node;
+
+use LogicException;
+use Twig\Compiler;
+use Twig\Node\Expression\AbstractExpression;
+use Twig\Node\Node;
+use Twig\Node\NodeCaptureInterface;
+
+/**
+ * Class TwigNodeLink
+ * @package Grav\Common\Twig\Node
+ */
+class TwigNodeLink extends Node implements NodeCaptureInterface
+{
+    /** @var string */
+    protected $tagName = 'link';
+
+    /**
+     * TwigNodeLink constructor.
+     * @param string|null $rel
+     * @param AbstractExpression|null $file
+     * @param AbstractExpression|null $group
+     * @param AbstractExpression|null $priority
+     * @param AbstractExpression|null $attributes
+     * @param int $lineno
+     * @param string|null $tag
+     */
+    public function __construct(?string $rel, ?AbstractExpression $file, ?AbstractExpression $group, ?AbstractExpression $priority, ?AbstractExpression $attributes, $lineno = 0, $tag = null)
+    {
+        $nodes = ['file' => $file, 'group' => $group, 'priority' => $priority, 'attributes' => $attributes];
+        $nodes = array_filter($nodes);
+
+        parent::__construct($nodes, ['rel' => $rel], $lineno, $tag);
+    }
+
+    /**
+     * Compiles the node to PHP.
+     *
+     * @param Compiler $compiler A Twig Compiler instance
+     * @return void
+     * @throws LogicException
+     */
+    public function compile(Compiler $compiler): void
+    {
+        $compiler->addDebugInfo($this);
+        if (!$this->hasNode('file')) {
+            return;
+        }
+
+        $compiler->write("\$assets = \\Grav\\Common\\Grav::instance()['assets'];\n");
+
+        $compiler->write('$attributes = [\'rel\' => \'' . $this->getAttribute('rel') . '\'];' . "\n");
+        if ($this->hasNode('attributes')) {
+            $compiler
+                ->write('$attributes += ')
+                ->subcompile($this->getNode('attributes'))
+                ->raw(";\n")
+                ->write("if (!is_array(\$attributes)) {\n")
+                ->indent()
+                ->write("throw new UnexpectedValueException('{% {$this->tagName} with x %}: x is not an array');\n")
+                ->outdent()
+                ->write("}\n");
+        }
+
+        if ($this->hasNode('group')) {
+            $compiler
+                ->write("\$attributes['group'] = ")
+                ->subcompile($this->getNode('group'))
+                ->raw(";\n")
+                ->write("if (!is_string(\$attributes['group'])) {\n")
+                ->indent()
+                ->write("throw new UnexpectedValueException('{% {$this->tagName} in x %}: x is not a string');\n")
+                ->outdent()
+                ->write("}\n");
+        }
+
+        if ($this->hasNode('priority')) {
+            $compiler
+                ->write("\$attributes['priority'] = (int)(")
+                ->subcompile($this->getNode('priority'))
+                ->raw(");\n");
+        }
+
+        $compiler
+            ->write('$assets->addLink(')
+            ->subcompile($this->getNode('file'))
+            ->raw(", \$attributes);\n");
+    }
+}

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

@@ -0,0 +1,109 @@
+<?php
+
+/**
+ * @package    Grav\Common\Twig
+ *
+ * @copyright  Copyright (c) 2015 - 2022 Trilby Media, LLC. All rights reserved.
+ * @license    MIT License; see LICENSE file for details.
+ */
+
+namespace Grav\Common\Twig\TokenParser;
+
+use Grav\Common\Twig\Node\TwigNodeLink;
+use Twig\Error\SyntaxError;
+use Twig\Token;
+use Twig\TokenParser\AbstractTokenParser;
+
+/**
+ * Adds a link to the document. First parameter is always value of `rel` without quotes.
+ *
+ * {% link icon 'theme://images/favicon.png' priority: 20 with { type: 'image/png' } %}
+ * {% link modulepreload 'plugin://grav-plugin/build/js/vendor.js' %}
+ */
+class TwigTokenParserLink extends AbstractTokenParser
+{
+    protected $rel = [
+        'alternate',
+        'author',
+        'dns-prefetch',
+        'help',
+        'icon',
+        'license',
+        'next',
+        'pingback',
+        'preconnect',
+        'prefetch',
+        'preload',
+        'prerender',
+        'prev',
+        'search',
+        'stylesheet',
+    ];
+
+    /**
+     * Parses a token and returns a node.
+     *
+     * @param Token $token
+     * @return TwigNodeLink
+     * @throws SyntaxError
+     */
+    public function parse(Token $token)
+    {
+        $lineno = $token->getLine();
+
+        [$rel, $file, $group, $priority, $attributes] = $this->parseArguments($token);
+
+        return new TwigNodeLink($rel, $file, $group, $priority, $attributes, $lineno, $this->getTag());
+    }
+
+    /**
+     * @param Token $token
+     * @return array
+     */
+    protected function parseArguments(Token $token): array
+    {
+        $stream = $this->parser->getStream();
+
+
+        $rel = null;
+        if ($stream->test(Token::NAME_TYPE, $this->rel)) {
+            $rel = $stream->getCurrent()->getValue();
+            $stream->next();
+        }
+
+        $file = null;
+        if (!$stream->test(Token::NAME_TYPE) && !$stream->test(Token::BLOCK_END_TYPE)) {
+            $file = $this->parser->getExpressionParser()->parseExpression();
+        }
+
+        $group = null;
+        if ($stream->nextIf(Token::NAME_TYPE, 'at')) {
+            $group = $this->parser->getExpressionParser()->parseExpression();
+        }
+
+        $priority = null;
+        if ($stream->nextIf(Token::NAME_TYPE, 'priority')) {
+            $stream->expect(Token::PUNCTUATION_TYPE, ':');
+            $priority = $this->parser->getExpressionParser()->parseExpression();
+        }
+
+        $attributes = null;
+        if ($stream->nextIf(Token::NAME_TYPE, 'with')) {
+            $attributes = $this->parser->getExpressionParser()->parseExpression();
+        }
+
+        $stream->expect(Token::BLOCK_END_TYPE);
+
+        return [$rel, $file, $group, $priority, $attributes];
+    }
+
+    /**
+     * Gets the tag name associated with this token parser.
+     *
+     * @return string The tag name
+     */
+    public function getTag(): string
+    {
+        return 'link';
+    }
+}