Add support for data-src attribute in IFRAME elements with src priority (#1497)

Author: Copilot

packages/fwfh_webview/lib/src/internal.dart

@@ -1,4 +1,5 @@
 const kTagIframe = 'iframe';
+const kAttributeIframeDataSrc = 'data-src';
 const kAttributeIframeHeight = 'height';
 const kAttributeIframeSandbox = 'sandbox';
 const kAttributeIframeSandboxAllowScripts = 'allow-scripts';

packages/fwfh_webview/lib/src/web_view_factory.dart

@@ -132,7 +132,11 @@ mixin WebViewFactory on WidgetFactory {
               }
 
               final a = meta.element.attributes;
-              final src = urlFull(a[kAttributeIframeSrc] ?? '');
+              final dataSrc = a[kAttributeIframeDataSrc];
+              final srcAttr = a[kAttributeIframeSrc];
+              final src = urlFull(
+                (srcAttr?.isNotEmpty == true) ? srcAttr! : (dataSrc ?? '')
+              );
               if (src == null) {
                 return widgets;
               }

packages/fwfh_webview/test/web_view_factory_test.dart

@@ -318,6 +318,32 @@ void main() {
     });
   });
 
+  group('data-src attribute', () {
+    testWidgets('renders with data-src', (tester) async {
+      const html = '<iframe data-src="$src"></iframe>';
+      final explained = await explain(tester, html);
+      expect(explained, contains('url=$src,'));
+    });
+
+    testWidgets('src takes priority over data-src', (tester) async {
+      const html = '<iframe data-src="$src/1" src="$src/2"></iframe>';
+      final explained = await explain(tester, html);
+      expect(explained, contains('url=$src/2,'));
+    });
+
+    testWidgets('falls back to data-src when src is empty', (tester) async {
+      const html = '<iframe data-src="$src" src=""></iframe>';
+      final explained = await explain(tester, html);
+      expect(explained, contains('url=$src,'));
+    });
+
+    testWidgets('uses src when data-src is missing', (tester) async {
+      const html = '<iframe src="$src"></iframe>';
+      final explained = await explain(tester, html);
+      expect(explained, contains('url=$src,'));
+    });
+  });
+
   group('errors', () {
     testWidgets('no src', (tester) async {
       const html = '<iframe></iframe>';
@@ -330,6 +356,12 @@ void main() {
       final explained = await explain(tester, html);
       expect(explained, equals('[widget0]'));
     });
+
+    testWidgets('bad data-src (cannot build full url)', (tester) async {
+      const html = '<iframe data-src="bad"></iframe>';
+      final explained = await explain(tester, html);
+      expect(explained, equals('[widget0]'));
+    });
   });
 }