Add RSS feed for Markdown blog posts

config/hyde.php

@@ -44,6 +44,8 @@
     |
     | Here are some configuration options for URL generation.
     |
+    | A site_url is required to use sitemaps and RSS feeds.
+    |
     | `site_url` is used to create canonical URLs and permalinks.
     | `prettyUrls` will when enabled create links that do not end in .html.
     | `generateSitemap` determines if a sitemap.xml file should be generated.

src/Commands/HydeBuildStaticSiteCommand.php

@@ -13,6 +13,7 @@
 use Hyde\Framework\Models\MarkdownPage;
 use Hyde\Framework\Models\MarkdownPost;
 use Hyde\Framework\Services\DiscoveryService;
+use Hyde\Framework\Services\RssFeedService;
 use Hyde\Framework\Services\SitemapService;
 use Illuminate\Support\Facades\Config;
 use Illuminate\Support\Facades\File;
@@ -172,9 +173,17 @@ public function postBuildActions(): void
         }
 
         if (SitemapService::canGenerateSitemap()) {
-            $this->info('Generating sitemap.xml');
+            $actionTime = microtime(true);
+            $this->comment('Generating sitemap...');
             file_put_contents(Hyde::getSiteOutputPath('sitemap.xml'), SitemapService::generateSitemap());
-            $this->newLine();
+            $this->line(' > Created <info>sitemap.xml</> in '.$this->getExecutionTimeInMs($actionTime)."ms\n");
+        }
+
+        if (RssFeedService::canGenerateFeed()) {
+            $actionTime = microtime(true);
+            $this->comment('Generating RSS feed...');
+            file_put_contents(Hyde::getSiteOutputPath(RssFeedService::getDefaultOutputFilename()), RssFeedService::generateFeed());
+            $this->line(' > Created <info>'.RssFeedService::getDefaultOutputFilename().'</> in '.$this->getExecutionTimeInMs($actionTime)."ms\n");
         }
     }
 
@@ -198,4 +207,9 @@ private function runNodeCommand(string $command, string $message, ?string $actio
             $output ?? '<fg=red>Could not '.($actionMessage ?? 'run script').'! Is NPM installed?</>'
         );
     }
+
+    protected function getExecutionTimeInMs(float $timeStart): float
+    {
+        return number_format(((microtime(true) - $timeStart) * 1000), 2);
+    }
 }

src/Models/Author.php

@@ -47,4 +47,14 @@ public function __construct(string $username, ?array $data = [])
             $this->website = $data['website'];
         }
     }
+
+    /**
+     * Get the author's name.
+     *
+     * @return string
+     */
+    public function getName(): string
+    {
+        return $this->name ?? $this->username;
+    }
 }

src/Models/MarkdownPost.php

@@ -6,6 +6,7 @@
 use Hyde\Framework\Concerns\HasAuthor;
 use Hyde\Framework\Concerns\HasDateString;
 use Hyde\Framework\Concerns\HasFeaturedImage;
+use Hyde\Framework\Hyde;
 use Hyde\Framework\Models\Parsers\MarkdownPostParser;
 
 class MarkdownPost extends MarkdownDocument
@@ -36,4 +37,14 @@ public function getCurrentPagePath(): string
     {
         return 'posts/'.$this->slug;
     }
+
+    public function getCanonicalLink(): string
+    {
+        return Hyde::uriPath(Hyde::pageLink($this->getCurrentPagePath().'.html'));
+    }
+
+    public function getPostDescription(): string
+    {
+        return $this->matter['description'] ?? substr($this->body, 0, 125).'...';
+    }
 }

src/Services/RssFeedService.php

@@ -0,0 +1,137 @@
+<?php
+
+namespace Hyde\Framework\Services;
+
+use Hyde\Framework\Hyde;
+use Hyde\Framework\Models\MarkdownPost;
+use SimpleXMLElement;
+
+/**
+ * @see \Tests\Feature\Services\RssFeedServiceTest
+ * @see https://validator.w3.org/feed/docs/rss2.html
+ */
+class RssFeedService
+{
+    public SimpleXMLElement $feed;
+
+    public function __construct()
+    {
+        $this->feed = new SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?>
+            <rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom" xmlns:dc="http://purl.org/dc/elements/1.1/" />');
+        $this->feed->addChild('channel');
+
+        $this->addInitialChannelItems();
+    }
+
+    public function generate(): self
+    {
+        /** @var MarkdownPost $post */
+        foreach (Hyde::getLatestPosts() as $post) {
+            $this->addItem($post);
+        }
+
+        return $this;
+    }
+
+    public function getXML(): string
+    {
+        return $this->feed->asXML();
+    }
+
+    protected function addItem(MarkdownPost $post): void
+    {
+        $item = $this->feed->channel->addChild('item');
+        $item->addChild('title', $post->findTitleForDocument());
+        $item->addChild('link', $post->getCanonicalLink());
+        $item->addChild('guid', $post->getCanonicalLink());
+        $item->addChild('description', $post->getPostDescription());
+
+        $this->addAdditionalItemData($item, $post);
+    }
+
+    protected function addAdditionalItemData(SimpleXMLElement $item, MarkdownPost $post): void
+    {
+        if (isset($post->date)) {
+            $item->addChild('pubDate', $post->date->dateTimeObject->format(DATE_RSS));
+        }
+
+        if (isset($post->author)) {
+            $item->addChild('dc:creator', $post->author->getName(), 'http://purl.org/dc/elements/1.1/');
+        }
+
+        if (isset($post->category)) {
+            $item->addChild('category', $post->category);
+        }
+
+        // Only support local images, as remote images would take extra time to make HTTP requests to get length
+        if (isset($post->image) && isset($post->image->path)) {
+            $image = $item->addChild('enclosure');
+            $image->addAttribute('url', Hyde::uriPath(str_replace('_media', 'media', $post->image->path)));
+            $image->addAttribute('type', str_ends_with($post->image->path, '.png') ? 'image/png' : 'image/jpeg');
+            $image->addAttribute('length', filesize(Hyde::path($post->image->path)));
+        }
+    }
+
+    protected function addInitialChannelItems(): void
+    {
+        $this->feed->channel->addChild('title', $this->getTitle());
+        $this->feed->channel->addChild('link', $this->getLink());
+        $this->feed->channel->addChild('description', $this->getDescription());
+
+        $atomLink = $this->feed->channel->addChild('atom:link', namespace: 'http://www.w3.org/2005/Atom');
+        $atomLink->addAttribute('href', $this->getLink().'/'.static::getDefaultOutputFilename());
+        $atomLink->addAttribute('rel', 'self');
+        $atomLink->addAttribute('type', 'application/rss+xml');
+
+        $this->addAdditionalChannelData();
+    }
+
+    protected function addAdditionalChannelData(): void
+    {
+        $this->feed->channel->addChild('language', config('hyde.language', 'en'));
+        $this->feed->channel->addChild('generator', 'HydePHP '.Hyde::version());
+        $this->feed->channel->addChild('lastBuildDate', date(DATE_RSS));
+    }
+
+    protected function getTitle(): string
+    {
+        return $this->xmlEscape(
+            config('hyde.name', 'HydePHP')
+        );
+    }
+
+    protected function getLink(): string
+    {
+        return $this->xmlEscape(
+            config('hyde.site_url') ?? 'http://localhost'
+        );
+    }
+
+    protected function getDescription(): string
+    {
+        return $this->xmlEscape(
+            config('hyde.rssDescription',
+                $this->getTitle().' RSS Feed')
+        );
+    }
+
+    protected function xmlEscape(string $string): string
+    {
+        return htmlspecialchars($string, ENT_XML1 | ENT_COMPAT, 'UTF-8');
+    }
+
+    public static function getDefaultOutputFilename(): string
+    {
+        return config('hyde.rssFilename', 'feed.rss');
+    }
+
+    public static function generateFeed(): string
+    {
+        return (new static)->generate()->getXML();
+    }
+
+    public static function canGenerateFeed(): bool
+    {
+        return (Hyde::uriPath() !== false) && config('hyde.generateRssFeed', true);
+    }
+}

tests/Feature/Commands/BuildStaticSiteCommandTest.php

@@ -112,10 +112,55 @@ public function test_sitemap_is_generated_when_conditions_are_met()
 
         unlinkIfExists(Hyde::path('_site/sitemap.xml'));
         $this->artisan('build')
-            ->expectsOutput('Generating sitemap.xml')
+            ->expectsOutput('Generating sitemap...')
             ->assertExitCode(0);
 
         $this->assertFileExists(Hyde::path('_site/sitemap.xml'));
+        unlink(Hyde::path('_site/sitemap.xml'));
+    }
+
+    public function test_rss_feed_is_not_generated_when_conditions_are_not_met()
+    {
+        config(['hyde.site_url' => '']);
+        config(['hyde.generateRssFeed' => false]);
+
+        unlinkIfExists(Hyde::path('_site/feed.rss'));
+        $this->artisan('build')
+            ->assertExitCode(0);
+
+        $this->assertFileDoesNotExist(Hyde::path('_site/feed.rss'));
+    }
+
+    public function test_rss_feed_is_generated_when_conditions_are_met()
+    {
+        config(['hyde.site_url' => 'https://example.com']);
+        config(['hyde.generateRssFeed' => true]);
+
+        unlinkIfExists(Hyde::path('_site/feed.rss'));
+        $this->artisan('build')
+            ->expectsOutput('Generating RSS feed...')
+            ->assertExitCode(0);
+
+        $this->assertFileExists(Hyde::path('_site/feed.rss'));
+        unlink(Hyde::path('_site/feed.rss'));
+    }
+
+    public function test_rss_filename_can_be_changed()
+    {
+        config(['hyde.site_url' => 'https://example.com']);
+        config(['hyde.generateRssFeed' => true]);
+        config(['hyde.rssFilename' => 'blog.xml']);
+
+        unlinkIfExists(Hyde::path('_site/feed.rss'));
+        unlinkIfExists(Hyde::path('_site/blog.xml'));
+
+        $this->artisan('build')
+            ->expectsOutput('Generating RSS feed...')
+            ->assertExitCode(0);
+
+        $this->assertFileDoesNotExist(Hyde::path('_site/feed.rss'));
+        $this->assertFileExists(Hyde::path('_site/blog.xml'));
+        unlink(Hyde::path('_site/blog.xml'));
     }
 
     /**