1 files changed, 31 insertions, 0 deletions
diff --git a/Digitigrade/FormattingProvider/SanitisedHtml.php b/Digitigrade/FormattingProvider/SanitisedHtml.php
new file mode 100644
index 0000000..fa2e5eb
--- /dev/null
+++ b/Digitigrade/FormattingProvider/SanitisedHtml.php
@@ -0,0 +1,31 @@
+<?php
+namespace Digitigrade\FormattingProvider;
+
+use Digitigrade\FormattingProvider;
+use Digitigrade\Singleton;
+use Symfony\Component\HtmlSanitizer\HtmlSanitizer;
+use Symfony\Component\HtmlSanitizer\HtmlSanitizerConfig;
+
+class SanitisedHtml extends Singleton implements FormattingProvider {
+    private HtmlSanitizer $sanitiser;
+
+    public const ALLOWED_URL_SCHEMES = [
+        'http', 'https', 'ftp', 'gopher', 'gemini', 'web+pawpub', 'web+ap', 'matrix', 'xmpp', 'mailto'
+    ];
+
+    protected function __construct() {
+        $this->sanitiser = new HtmlSanitizer((new HtmlSanitizerConfig())
+            ->allowSafeElements()
+            ->allowLinkSchemes(self::ALLOWED_URL_SCHEMES)
+        );
+    }
+
+    public function renderToHtml(string $input): string {
+        return $this->sanitiser->sanitize($input);
+    }
+
+    public function renderToPlainText(string $input): string {
+        // TODO: somehow remove tags and leave the unformatted content behind
+        return htmlspecialchars($input);
+    }
+}
+\ No newline at end of file