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feat: Add support for file:// URIs in iOS and macOS WebView #21573

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feat: Add support for file:// URIs in iOS and macOS WebView #21573

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440fc5a
Initial plan
Copilot Oct 7, 2025
eecf9e9
feat: Add file:// URI support for iOS WebView
Copilot Oct 7, 2025
21ca8b1
test: Add runtime test for file:// URI with relative paths
Copilot Oct 7, 2025
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3 changes: 3 additions & 0 deletions src/Uno.UI.Runtime.Skia.MacOS/UnoNativeMac/UnoNativeMac/UNOWebView.m
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Expand Up @@ -88,6 +88,9 @@ void uno_set_webview_unsupported_scheme_identified_callback(uno_webview_unsuppor
config.preferences.javaScriptCanOpenWindowsAutomatically = true;
config.mediaTypesRequiringUserActionForPlayback = WKAudiovisualMediaTypeVideo | WKAudiovisualMediaTypeAudio;

// Enable file access from file URLs to support relative paths in local HTML content
[config.preferences setValue:@YES forKey:@"allowFileAccessFromFileURLs"];

UNOWebView* webview = [[UNOWebView alloc] initWithFrame:NSMakeRect(0,0,0,0) configuration:config];
#if DEBUG
NSLog(@"uno_webview_create %p", webview);
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5 changes: 5 additions & 0 deletions src/Uno.UI.RuntimeTests/Assets/WebView_FileAccess_Test.css
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@@ -0,0 +1,5 @@
#test-div {
background-color: green;
color: white;
padding: 10px;
}
22 changes: 22 additions & 0 deletions src/Uno.UI.RuntimeTests/Assets/WebView_FileAccess_Test.html
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@@ -0,0 +1,22 @@
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>File Access Test</title>
<link rel="stylesheet" href="WebView_FileAccess_Test.css">
</head>
<body>
<div id="test-div">Test Content</div>
<script>
// Set a flag that can be checked by the test to verify the page loaded
window.fileAccessTestLoaded = true;

// Check if CSS was loaded by reading the computed style
window.addEventListener('load', function() {
var testDiv = document.getElementById('test-div');
var computedStyle = window.getComputedStyle(testDiv);
window.cssLoaded = computedStyle.backgroundColor === 'rgb(0, 128, 0)' || computedStyle.backgroundColor === 'green';
});
</script>
</body>
</html>
44 changes: 44 additions & 0 deletions src/Uno.UI.RuntimeTests/Tests/Windows_UI_Xaml_Controls/Given_WebView.cs
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Expand Up @@ -246,5 +246,49 @@ public async Task When_InvokeScriptAsync_Non_String()
Assert.AreEqual("", result);
}
#endif

#if __IOS__ || __SKIA__
[TestMethod]
public async Task When_FileUri_With_Relative_Paths()
{
var border = new Border();
var webView = new WebView();
webView.Width = 200;
webView.Height = 200;
border.Child = webView;
TestServices.WindowHelper.WindowContent = border;
await TestServices.WindowHelper.WaitForLoaded(border);

bool navigationStarting = false;
bool navigationDone = false;
webView.NavigationStarting += (s, e) => navigationStarting = true;
webView.NavigationCompleted += (s, e) => navigationDone = true;

// Get the path to the test HTML file
var testHtmlPath = System.IO.Path.Combine(
global::Windows.ApplicationModel.Package.Current.InstalledLocation.Path,
"Assets",
"WebView_FileAccess_Test.html");

// Navigate to the file:// URI
var fileUri = new Uri($"file://{testHtmlPath}");
webView.Source = fileUri;

await TestServices.WindowHelper.WaitFor(() => navigationStarting, 3000);
await TestServices.WindowHelper.WaitFor(() => navigationDone, 3000);

// Wait a bit for the page to fully load and execute scripts
await Task.Delay(500);

// Verify the page loaded
var pageLoaded = await webView.InvokeScriptAsync("eval", new[] { "window.fileAccessTestLoaded ? 'true' : 'false'" });
Assert.AreEqual("true", pageLoaded, "HTML page should have loaded");

// Verify the CSS file was loaded and applied
// This tests that relative file:// URIs work correctly
var cssLoaded = await webView.InvokeScriptAsync("eval", new[] { "window.cssLoaded ? 'true' : 'false'" });
Assert.AreEqual("true", cssLoaded, "CSS file should have been loaded via relative path");
}
#endif
}
#endif
3 changes: 3 additions & 0 deletions src/Uno.UI/UI/Xaml/Controls/WebView/Native/iOSmacOS/UnoWKWebView.iOSmacOS.cs
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Expand Up @@ -88,6 +88,9 @@ partial class UnoWKWebView : WKWebView, INativeWebView, IWKScriptMessageHandler

Configuration.UserContentController.AddScriptMessageHandler(this, WebMessageHandlerName);

// Enable file access from file URLs to support relative paths in local HTML content
Configuration.Preferences.SetValueForKey(NSObject.FromObject(true), (NSString)"allowFileAccessFromFileURLs");

// Set strings with fallback to default English
OkString = !string.IsNullOrEmpty(ok) ? ok : "OK";
CancelString = !string.IsNullOrEmpty(cancel) ? cancel : "Cancel";
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