release: v3.1.0 premium smart core engines and 14 new accessibility rules

src/Rules/DuplicateH1.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace YakNet\AccessibilityConsole\Rules;
+
+use DOMElement;
+use YakNet\AccessibilityConsole\Core\Severity;
+use YakNet\AccessibilityConsole\Core\Violation;
+use YakNet\AccessibilityConsole\Core\WCAGStandard;
+
+class DuplicateH1 extends AbstractRule
+{
+    public function getId(): string { return 'WCAG_1_3_1_DUPLICATE_H1'; }
+    public function getDescription(): string { return 'Pages should not contain more than one h1 element.'; }
+    public function getStandard(): WCAGStandard { return WCAGStandard::A; }
+    public function getSeverity(): Severity { return Severity::WARNING; }
+    public function getLevel(): int { return 2; }
+
+    public function check(DOMElement $element): ?Violation
+    {
+        if (strtolower($element->tagName) !== 'h1') {
+            return null;
+        }
+
+        $doc = $element->ownerDocument;
+        if ($doc) {
+            $h1s = $doc->getElementsByTagName('h1');
+            if ($h1s->length > 1 && $h1s->item(0) !== $element) {
+                return $this->createViolation(
+                    $element,
+                    $this->getDescription(),
+                    'Change this heading to an h2 or lower level heading, keeping only one h1 per page.'
+                );
+            }
+        }
+
+        return null;
+    }
+}