✨ Add own helpers plugin

.gitignore

@@ -68,4 +68,5 @@ Icon
 # ---------------
 
 /kirby
-/site/plugins
+/site/plugins/*
+!/site/plugins/kirby-helpers

site/plugins/kirby-helpers/index.php

@@ -0,0 +1,7 @@
+<?php
+
+use Kirby\Filesystem\F;
+
+F::loadClasses([
+    'Mmk2410\\KirbyHelpers\\RssFeed' => 'src/RssFeed.php'
+], __DIR__);

site/plugins/kirby-helpers/src/RssFeed.php

@@ -0,0 +1,151 @@
+<?php
+
+namespace Mmk2410\KirbyHelpers;
+
+use Kirby\Cms\Page;
+use Kirby\Cms\Pages;
+use Kirby\Cms\Site;
+use XMLWriter;
+
+class RssFeed
+{
+    private XMLWriter $writer;
+
+    private int $openElements = 0;
+
+    public function __construct(
+        private Site $site,
+        private Pages $articles,
+        private string $path
+    ) {}
+
+    public function generate(): string
+    {
+        $this->createWriter();
+        $this->initialiseDocument();
+        $this->writeMetadata();
+
+        foreach ($this->articles as $article) {
+            /** @var Kirby\Cms\Page $article */
+            $this->writeArticle($article);
+        }
+
+        $this->finishDocument();
+
+        return $this->writer->outputMemory();
+    }
+
+    private function createWriter(): void
+    {
+        $this->writer = new XMLWriter();
+        $this->writer->openMemory();
+        $this->writer->setIndent(true);
+        $this->writer->setIndentString('  ');
+    }
+
+    private function initialiseDocument(): void
+    {
+        $this->writer->startDocument('1.0', 'UTF-8', 'yes');
+        $this->writer->startElement('rss');
+        $this->writer->writeAttribute('version', '2.0');
+        $this->writer->writeAttributeNs('xmlns', 'atom', null, 'http://www.w3.org/2005/Atom');
+    }
+
+    private function writeMetadata(): void
+    {
+        $this->openElement('channel');
+        $this->writer->writeElement('title', $this->title());
+        $this->writer->writeElement('link', url());
+        $this->writer->writeElement('description', $this->description());
+        $this->writer->writeElement('language', 'en-GB');
+        $this->writer->writeElement('lastBuildDate', $this->lastBuildDate());
+        $this->writer->writeElement('generator', 'Kirby CMS');
+        $this->writer->writeElement('docs', 'https://www.rssboard.org/rss-specification');
+
+        $this->writeMetadataAtomLink();
+        $this->writeMetadataImage();
+    }
+
+    private function writeMetadataAtomLink(): void
+    {
+        $this->openElementNs('atom', 'link', null);
+        $this->writer->writeAttribute('href', url($this->path));
+        $this->writer->writeAttribute('rel', 'self');
+        $this->writer->writeAttribute('type', 'application/rss+xml');
+        $this->closeElement();
+    }
+
+    private function writeMetadataImage(): void
+    {
+        $this->openElement('image');
+        $this->writer->writeElement('url', url('/assets/img/favicon/favicon.png'));
+        $this->writer->writeElement('title', $this->title());
+        $this->writer->writeElement('link', url());
+        $this->closeElement();
+    }
+
+    private function writeArticle(Page $article): void
+    {
+        $this->openElement('item');
+
+        $this->writer->writeElement('title', $article->title()->toString());
+        $this->writer->writeElement('link', url($article->url()));
+        $this->writer->writeElement('guid', url($article->url()));
+        $this->writer->writeElement('pubDate', $article->date()->toDate(DATE_RSS));
+
+        $this->openElement('description');
+        $this->writer->writeCdata($article->text()->kirbytext()->toString());
+        $this->closeElement(); // description
+
+        $this->closeElement(); // item
+    }
+
+    private function finishDocument(): void
+    {
+        $this->closeRemainingElements();
+        $this->writer->endDocument();
+    }
+
+    private function title(): string
+    {
+        return $this->site->title()->toString();
+    }
+
+    private function description(): string
+    {
+        return $this->site->description()->toString();
+    }
+
+    private function lastBuildDate(): string
+    {
+        return $this->articles->first()->date()->toDate(DATE_RSS);
+    }
+
+    private function openElement(string $name): void
+    {
+        $this->writer->startElement($name);
+        $this->openElements++;
+    }
+
+    private function openElementNs(
+        ?string $prefix,
+        string $name,
+        ?string $namespace
+    ): void {
+        $this->writer->startElementNs($prefix, $name, $namespace);
+        $this->openElements++;
+    }
+
+    private function closeElement(): void
+    {
+        $this->writer->endElement();
+        $this->openElements--;
+    }
+
+    private function closeRemainingElements(): void
+    {
+        while ($this->openElements > 0) {
+            $this->closeElement();
+        }
+    }
+}