|
| 1 | +CoreWebView2Frame.FrameCreated API |
| 2 | +=== |
| 3 | + |
| 4 | +# Background |
| 5 | +At present, WebView2 enables developers to track only first-level |
| 6 | +iframes, which are the direct child iframes of the main frame. |
| 7 | +However, we see that WebView2 customers want to manage nested |
| 8 | +iframes, such as recording the navigation history for a second |
| 9 | +level iframe. To address this, we will introduce the |
| 10 | +`CoreWebView2Frame.FrameCreated` API. This new API will allow |
| 11 | +developers to subscribe to the nested iframe creation event, |
| 12 | +giving them access to all properties, methods, and events of |
| 13 | +[CoreWebView2Frame](https://learn.microsoft.com/dotnet/api/microsoft.web.webview2.core.corewebview2frame) |
| 14 | +for the nested iframe. |
| 15 | + |
| 16 | +With the new API, developers can manage iframe tracking on a page |
| 17 | +contains multiple levels of iframes. They can choose track only the |
| 18 | +main page and first-level iframes (the default behavior), a partial |
| 19 | +WebView2 frames tree with specific iframes of interest, or the full |
| 20 | +WebView2 frames tree. |
| 21 | + |
| 22 | +# Examples |
| 23 | +## Track partial WebView2 Frames Tree |
| 24 | +### C++ Sample |
| 25 | +```cpp |
| 26 | +wil::com_ptr<ICoreWebView2> m_webview; |
| 27 | +std::map<UINT32, std::vector<std::wstring>> m_frame_navigation_urls; |
| 28 | +// In this example, we present a scenario where a WebView2 application wants to |
| 29 | +// manage the navigation of third-party content residing in second-level iframes |
| 30 | +// (Main frame -> First-level frame -> Second-level third-party frames). |
| 31 | +void TrackThirdPartyFrameNavigations() |
| 32 | +{ |
| 33 | + auto webview2_4 = m_webView.try_query<ICoreWebView2_4>(); |
| 34 | + if (webview2_4) |
| 35 | + { |
| 36 | + webview2_4->add_FrameCreated( |
| 37 | + Callback<ICoreWebView2FrameCreatedEventHandler>( |
| 38 | + [this](ICoreWebView2* sender, ICoreWebView2FrameCreatedEventArgs* args) |
| 39 | + noexcept -> HRESULT |
| 40 | + { |
| 41 | + // [AddFrameCreated] |
| 42 | + wil::com_ptr<ICoreWebView2Frame> webviewFrame; |
| 43 | + CHECK_FAILURE(args->get_Frame(&webviewFrame)); |
| 44 | + |
| 45 | + // Track nested (second-level) webview frame. |
| 46 | + auto frame7 = webviewFrame.try_query<ICoreWebView2Frame7>(); |
| 47 | + if (frame7) |
| 48 | + { |
| 49 | + frame7->add_FrameCreated( |
| 50 | + Callback<ICoreWebView2FrameChildFrameCreatedEventHandler>( |
| 51 | + [this]( |
| 52 | + ICoreWebView2Frame* sender, |
| 53 | + ICoreWebView2FrameCreatedEventArgs* args) noexcept |
| 54 | + -> HRESULT |
| 55 | + { |
| 56 | + wil::com_ptr<ICoreWebView2Frame> webviewFrame; |
| 57 | + CHECK_FAILURE(args->get_Frame(&webviewFrame)); |
| 58 | + |
| 59 | + wil::com_ptr<ICoreWebView2Frame2> frame2 = |
| 60 | + webviewFrame.try_query<ICoreWebView2Frame2>(); |
| 61 | + if (frame2) |
| 62 | + { |
| 63 | + // Subscribe to nested (second-level) webview frame |
| 64 | + // navigation starting event. |
| 65 | + frame2->add_NavigationStarting( |
| 66 | + Callback< |
| 67 | + ICoreWebView2FrameNavigationStartingEventHandler>( |
| 68 | + [this]( |
| 69 | + ICoreWebView2Frame* sender, |
| 70 | + ICoreWebView2NavigationStartingEventArgs* args) |
| 71 | + noexcept -> HRESULT |
| 72 | + { |
| 73 | + // Manage the navigation, e.g. cancel the |
| 74 | + // navigation if it's on block list. |
| 75 | + |
| 76 | + UINT32 frameId = 0; |
| 77 | + auto frame5 = |
| 78 | + wil::try_query<ICoreWebView2Frame5>(sender); |
| 79 | + if (frame5) |
| 80 | + { |
| 81 | + CHECK_FAILURE( |
| 82 | + frame5->get_FrameId(&frameId)); |
| 83 | + } |
| 84 | + wil::unique_cotaskmem_string uri; |
| 85 | + CHECK_FAILURE(args->get_Uri(&uri)); |
| 86 | + |
| 87 | + // Log the navigation history per frame Id. |
| 88 | + m_frame_navigation_urls[frameId].push_back(uri.get()); |
| 89 | + return S_OK; |
| 90 | + }) |
| 91 | + .Get(), |
| 92 | + nullptr); |
| 93 | + } |
| 94 | + return S_OK; |
| 95 | + }) |
| 96 | + .Get(), |
| 97 | + nullptr); |
| 98 | + } |
| 99 | + // [AddFrameCreated] |
| 100 | + return S_OK; |
| 101 | + }) |
| 102 | + .Get(), |
| 103 | + nullptr); |
| 104 | + } |
| 105 | +} |
| 106 | + |
| 107 | +``` |
| 108 | +### C# Sample |
| 109 | +```c# |
| 110 | +var _frameNavigationUrls = new Dictionary<UINT32, List<string>>(); |
| 111 | +// In this example, we present a scenario where a WebView2 application wants to |
| 112 | +// manage the navigation of third-party content residing in second-level iframes |
| 113 | +// (Main frame -> First-level frame -> second-level third-party frames). |
| 114 | +void TrackThirdPartyFrameNavigations() |
| 115 | +{ |
| 116 | + webView.CoreWebView2.FrameCreated += (sender, args) => |
| 117 | + { |
| 118 | + // Track nested (second-level) webview frame. |
| 119 | + args.Frame.FrameCreated += (frameCreatedSender, frameCreatedArgs) => |
| 120 | + { |
| 121 | + CoreWebView2Frame childFrame = frameCreatedArgs.Frame; |
| 122 | + childFrame.NavigationStarting += OnFrameNavigationStarting; |
| 123 | + }; |
| 124 | + }; |
| 125 | +} |
| 126 | + |
| 127 | +void OnFrameNavigationStarting(object sender, |
| 128 | + CoreWebView2NavigationStartingEventArgs args) |
| 129 | +{ |
| 130 | + // Manage the navigation, e.g. cancel the navigation |
| 131 | + // if it's on block list. |
| 132 | + CoreWebView2Frame frame = (CoreWebView2Frame)sender; |
| 133 | + if (!_frameNavigationUrls.ContainsKey(frame.FrameId)) |
| 134 | + { |
| 135 | + _frameNavigationUrls[frame.FrameId] = new List<string>(); |
| 136 | + } |
| 137 | + // Log the navigation history per frame Id. |
| 138 | + _frameNavigationUrls[frame.FrameId].Add(args.Uri); |
| 139 | +} |
| 140 | +``` |
| 141 | + |
| 142 | +## Track entire WebView2 Frames Tree |
| 143 | +### C++ Sample |
| 144 | +```C++ |
| 145 | +wil::com_ptr<ICoreWebView2> m_webview; |
| 146 | +std::map<UINT32, std::vector<std::wstring>> m_frame_navigation_urls; |
| 147 | +void OnFrameCreated(wil::com_ptr<ICoreWebView2Frame> webviewFrame); |
| 148 | +// In this example, we present a scenario where a WebView2 application |
| 149 | +// wants to manage the navigation in all iframes. |
| 150 | +void TrackAllFrameNavigations() |
| 151 | +{ |
| 152 | + auto webview2_4 = m_webview.try_query<ICoreWebView2_4>(); |
| 153 | + if (webview2_4) |
| 154 | + { |
| 155 | + webview2_4->add_FrameCreated( |
| 156 | + Callback<ICoreWebView2FrameCreatedEventHandler>( |
| 157 | + [this](ICoreWebView2* sender, ICoreWebView2FrameCreatedEventArgs* args) |
| 158 | + noexcept -> HRESULT |
| 159 | + { |
| 160 | + wil::com_ptr<ICoreWebView2Frame> webviewFrame; |
| 161 | + CHECK_FAILURE(args->get_Frame(&webviewFrame)); |
| 162 | + // Track first-level webview frame. |
| 163 | + OnFrameCreated(webviewFrame); |
| 164 | + return S_OK; |
| 165 | + }) |
| 166 | + .Get(), |
| 167 | + nullptr); |
| 168 | + } |
| 169 | +} |
| 170 | + |
| 171 | +void OnFrameCreated(wil::com_ptr<ICoreWebView2Frame> webviewFrame) |
| 172 | +{ |
| 173 | + auto frame7 = webviewFrame.try_query<ICoreWebView2Frame7>(); |
| 174 | + if (frame7) |
| 175 | + { |
| 176 | + //! [AddFrameCreated] |
| 177 | + frame7->add_FrameCreated( |
| 178 | + Callback<ICoreWebView2FrameChildFrameCreatedEventHandler>( |
| 179 | + [this]( |
| 180 | + ICoreWebView2Frame* sender, |
| 181 | + ICoreWebView2FrameCreatedEventArgs* args) noexcept -> HRESULT |
| 182 | + { |
| 183 | + wil::com_ptr<ICoreWebView2Frame> webviewFrame; |
| 184 | + CHECK_FAILURE(args->get_Frame(&webviewFrame)); |
| 185 | + // Make a recursive call to track all nested |
| 186 | + // webview frame. |
| 187 | + OnFrameCreated(webviewFrame); |
| 188 | + return S_OK; |
| 189 | + }) |
| 190 | + .Get(), |
| 191 | + nullptr); |
| 192 | + //! [AddFrameCreated] |
| 193 | + } |
| 194 | + |
| 195 | + // Subscribe to webview frame navigation starting event. |
| 196 | + wil::com_ptr<ICoreWebView2Frame2> frame2 = webviewFrame.try_query<ICoreWebView2Frame2>(); |
| 197 | + if (frame2) |
| 198 | + { |
| 199 | + frame2->add_NavigationStarting( |
| 200 | + Callback<ICoreWebView2FrameNavigationStartingEventHandler>( |
| 201 | + [this]( |
| 202 | + ICoreWebView2Frame* sender, |
| 203 | + ICoreWebView2NavigationStartingEventArgs* args) noexcept -> HRESULT |
| 204 | + { |
| 205 | + // Manage the navigation, e.g. cancel the |
| 206 | + // navigation if it's on block list. |
| 207 | + |
| 208 | + UINT32 frameId = 0; |
| 209 | + auto frame5 = wil::try_query<ICoreWebView2Frame5>(sender); |
| 210 | + if (frame5) |
| 211 | + { |
| 212 | + CHECK_FAILURE(frame5->get_FrameId(&frameId)); |
| 213 | + } |
| 214 | + wil::unique_cotaskmem_string uri; |
| 215 | + CHECK_FAILURE(args->get_Uri(&uri)); |
| 216 | + |
| 217 | + // Log the navigation history per frame Id. |
| 218 | + m_frame_navigation_urls[frameId].push_back(uri.get()); |
| 219 | + return S_OK; |
| 220 | + }) |
| 221 | + .Get(), |
| 222 | + nullptr); |
| 223 | + } |
| 224 | +} |
| 225 | +``` |
| 226 | +
|
| 227 | +### C# Sample |
| 228 | +```C# |
| 229 | +var _frameNavigationUrls = new Dictionary<UINT32, List<string>>(); |
| 230 | +// In this example, we present a scenario where a WebView2 application |
| 231 | +// wants to manage the navigation in all iframes. |
| 232 | +void TrackAllFrameNavigations(object target, ExecutedRoutedEventArgs e) |
| 233 | +{ |
| 234 | + webView.CoreWebView2.FrameCreated += OnFrameCreated; |
| 235 | +} |
| 236 | +
|
| 237 | +void OnFrameCreated(object sender, CoreWebView2FrameCreatedEventArgs args) |
| 238 | +{ |
| 239 | + CoreWebView2Frame childFrame = args.Frame; |
| 240 | + // Make a recursive call to track all nested webview frames event. |
| 241 | + childFrame.FrameCreated += OnFrameCreated; |
| 242 | + childFrame.NavigationStarting += OnFrameNavigationStarting; |
| 243 | +} |
| 244 | +
|
| 245 | +void OnFrameNavigationStarting(object sender, CoreWebView2NavigationStartingEventArgs args) |
| 246 | +{ |
| 247 | + // Manage the navigation, e.g. cancel the navigation |
| 248 | + // if it's on block list. |
| 249 | + CoreWebView2Frame frame = (CoreWebView2Frame)sender; |
| 250 | + if (!_frameNavigationUrls.ContainsKey(frame.FrameId)) |
| 251 | + { |
| 252 | + _frameNavigationUrls[frame.FrameId] = new List<string>(); |
| 253 | + } |
| 254 | + // Log the navigation history per frame Id. |
| 255 | + _frameNavigationUrls[frame.FrameId].Add(args.Uri); |
| 256 | +} |
| 257 | +``` |
| 258 | + |
| 259 | +# API Details |
| 260 | +## C++ |
| 261 | +```C++ |
| 262 | +/// Receives `FrameCreated` events. |
| 263 | +interface ICoreWebView2FrameChildFrameCreatedEventHandler : IUnknown { |
| 264 | + /// Provides the event args for the corresponding event. |
| 265 | + HRESULT Invoke( |
| 266 | + [in] ICoreWebView2Frame* sender, |
| 267 | + [in] ICoreWebView2FrameCreatedEventArgs* args); |
| 268 | +} |
| 269 | + |
| 270 | +/// This is the ICoreWebView2Frame interface. |
| 271 | +interface ICoreWebView2Frame7 : IUnknown { |
| 272 | + /// Adds an event handler for the `FrameCreated` event. |
| 273 | + /// Raised when a new direct descendant iframe is created. |
| 274 | + /// Handle this event to get access to `ICoreWebView2Frame` objects. |
| 275 | + /// Use `ICoreWebView2Frame::add_Destroyed` to listen for when this |
| 276 | + /// iframe goes away. |
| 277 | + /// |
| 278 | + /// \snippet ScenarioWebViewEventMonitor.cpp AddFrameCreated |
| 279 | + HRESULT add_FrameCreated( |
| 280 | + [in] ICoreWebView2FrameChildFrameCreatedEventHandler* eventHandler, |
| 281 | + [out] EventRegistrationToken* token); |
| 282 | + |
| 283 | + /// Removes an event handler previously added with `add_FrameCreated`. |
| 284 | + HRESULT remove_FrameCreated( |
| 285 | + [in] EventRegistrationToken token); |
| 286 | +} |
| 287 | +``` |
| 288 | + |
| 289 | +## C# |
| 290 | +```c# |
| 291 | +namespace Microsoft.Web.WebView2.Core |
| 292 | +{ |
| 293 | + runtimeclass CoreWebView2Frame |
| 294 | + { |
| 295 | + [interface_name("Microsoft.Web.WebView2.Core.ICoreWebView2Frame7")] |
| 296 | + { |
| 297 | + event Windows.Foundation.TypedEventHandler<CoreWebView2Frame, CoreWebView2FrameCreatedEventArgs> FrameCreated; |
| 298 | + } |
| 299 | + } |
| 300 | +} |
| 301 | +``` |
| 302 | + |
| 303 | +# Appendix |
| 304 | +## Impacted API |
| 305 | +### `CoreWebView2Frame.PermissionRequested` and `CoreWebView2Frame.ScreenCaptureStarting` |
| 306 | +In the current case of nested iframes, the [PermissionRequested](https://learn.microsoft.com/microsoft-edge/webview2/reference/winrt/microsoft_web_webview2_core/corewebview2frame#permissionrequested) |
| 307 | +and [ScreenCaptureStarting](https://learn.microsoft.com/microsoft-edge/webview2/reference/winrt/microsoft_web_webview2_core/corewebview2frame#screencapturestarting) |
| 308 | +events will be raised from the top-level iframe. With the support |
| 309 | +of tracking nested iframes, we can now handle these requests directly |
| 310 | +within the nested iframe. Specifically, these requests are raised to |
| 311 | +the nearest tracked frame, which is the `CoreWebView2Frame` closest |
| 312 | +to the frame that initiates the request (from bottom to top). |
| 313 | +``` |
| 314 | +// Example: |
| 315 | +// A (main frame/CoreWebView2) |
| 316 | +// | |
| 317 | +// B (first-level iframe/CoreWebView2Frame) |
| 318 | +// | |
| 319 | +// C (nested iframe) |
| 320 | +// | |
| 321 | +// D (nested iframe) |
| 322 | +``` |
| 323 | +Suppose there's a `PermissionRequest` comes from D. |
| 324 | +* If D is a tracked frame (`CoreWebView2Frame`), then D is the |
| 325 | +closest tracked frame from which the request will be raised from. |
| 326 | +* If D is not being tracked, and C is a tracked frame. Then C |
| 327 | +is the closest tracked frame from which the request will be |
| 328 | +raised from. |
| 329 | +* If neither C nor D is tracked, then B is the closest tracked |
| 330 | +frame from which the request will be raised. This case applies |
| 331 | +to current `PermissionRequested` developers, as they haven't |
| 332 | +subscribed to the `CoreWebView2Frame.FrameCreated` event. |
| 333 | +Consequently, there is no change in behavior, and requests |
| 334 | +originating from iframes will continue to be raised from the |
| 335 | +first-level iframe. |
| 336 | + |
| 337 | +If the `PermissionRequested` event is not handled in the current |
| 338 | +tracked frame, the request will propagate to its parent |
| 339 | +`CoreWebView2Frame`, or to `CoreWebView2` if the parent frame |
| 340 | +is the main frame. For example, if frame D is tracked but does |
| 341 | +not handle the request, the request will bubble up to frame C. |
| 342 | +If frame C handles the request, it will not propagate further |
| 343 | +to its parent frame B. |
| 344 | + |
| 345 | +### `CoreWebView2.ProcessFailed` |
| 346 | +With the support of tracking nested iframes, the processes |
| 347 | +which support these nested iframes will be also tracked by |
| 348 | +[ProcessFailed](https://learn.microsoft.com/dotnet/api/microsoft.web.webview2.core.corewebview2.processfailed). |
| 349 | +As we only track processes running tracked iframes, existing |
| 350 | +developers will not receive any process failed events specific |
| 351 | +to nested iframes as they haven't subscribed to the |
| 352 | +`CoreWebView2Frame.FrameCreated` event. |
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