interface ICoreWebView2Frame3

interface ICoreWebView2Frame3
  : public ICoreWebView2Frame2

This is an extension of the ICoreWebView2Frame interface that supports PermissionRequested.

Summary

Members	Descriptions
add_PermissionRequested	Adds an event handler for the PermissionRequested event.
remove_PermissionRequested	Removes an event handler previously added with add_PermissionRequested.

Applies to

Product	Introduced
WebView2 Win32	1.0.1185.39
WebView2 Win32 Prerelease	1.0.1158

Members

add_PermissionRequested

Adds an event handler for the PermissionRequested event.

public HRESULT add_PermissionRequested(ICoreWebView2FramePermissionRequestedEventHandler * eventHandler, EventRegistrationToken * token)

Add an event handler for the PermissionRequested event. PermissionRequested is raised when content in an iframe any of its descendant iframes requests permission to privileged resources.

This relates to the PermissionRequested event on the CoreWebView2. Both these events will be raised in the case of an iframe requesting permission. The CoreWebView2Frame's event handlers will be invoked before the event handlers on the CoreWebView2. If the Handled property of the PermissionRequestedEventArgs is set to TRUE within the CoreWebView2Frame event handler, then the event will not be raised on the CoreWebView2, and it's event handlers will not be invoked.

In the case of nested iframes, the 'PermissionRequested' event will be raised from the top level iframe.

If a deferral is not taken on the event args, the subsequent scripts are blocked until the event handler returns. If a deferral is taken, the scripts are blocked until the deferral is completed.

    m_webView4 = m_webView.try_query<ICoreWebView2_4>();
    if (m_webView4)
    {
        CHECK_FAILURE(m_webView4->add_FrameCreated(
            Callback<ICoreWebView2FrameCreatedEventHandler>(
                [this](ICoreWebView2* sender, ICoreWebView2FrameCreatedEventArgs* args) -> HRESULT {
                    wil::com_ptr<ICoreWebView2Frame> webviewFrame;
                    CHECK_FAILURE(args->get_Frame(&webviewFrame));

                    m_frame3 = webviewFrame.try_query<ICoreWebView2Frame3>();
                    if (m_frame3)
                    {
                        CHECK_FAILURE(m_frame3->add_PermissionRequested(
                            Callback<ICoreWebView2FramePermissionRequestedEventHandler>(
                                this, &ScenarioIFrameDevicePermission::OnPermissionRequested
                            ).Get(),
                            &m_PermissionRequestedToken));
                    }
                    else {
                        m_appWindow->RunAsync([]{ FeatureNotAvailable(); });
                    }
                    m_webView4->remove_FrameCreated(m_FrameCreatedToken);
                    return S_OK;
            }).Get(),
            &m_FrameCreatedToken));
    }
    else
    {
        FeatureNotAvailable();
    }

HRESULT ScenarioIFrameDevicePermission::OnPermissionRequested(
    ICoreWebView2Frame* sender, ICoreWebView2PermissionRequestedEventArgs2* args)
{
    // If we set Handled to true, then we will not fire the PermissionRequested
    // event off of the CoreWebView2.
    args->put_Handled(true);

    // Obtain a deferral for the event so that the CoreWebView2
    // doesn't examine the properties we set on the event args until
    // after we call the Complete method asynchronously later.
    wil::com_ptr<ICoreWebView2Deferral> deferral;
    CHECK_FAILURE(args->GetDeferral(&deferral));

    // Do the rest asynchronously, to avoid calling MessageBox in an event handler.
    m_appWindow->RunAsync([this, deferral, args]
    {
        COREWEBVIEW2_PERMISSION_KIND kind = COREWEBVIEW2_PERMISSION_KIND_UNKNOWN_PERMISSION;
        BOOL userInitiated = FALSE;
        wil::unique_cotaskmem_string uri;
        CHECK_FAILURE(args->get_PermissionKind(&kind));
        CHECK_FAILURE(args->get_IsUserInitiated(&userInitiated));
        CHECK_FAILURE(args->get_Uri(&uri));

        COREWEBVIEW2_PERMISSION_STATE state;

        auto cached_key = std::make_tuple(std::wstring(uri.get()), kind, userInitiated);
        auto cached_permission = m_cached_permissions.find(cached_key);
        if (cached_permission != m_cached_permissions.end())
        {
            state = (cached_permission->second
                ? COREWEBVIEW2_PERMISSION_STATE_ALLOW
                : COREWEBVIEW2_PERMISSION_STATE_DENY);
        }
        else
        {
            std::wstring message = L"An iframe has requested device permission for ";
            message += PermissionKindToString(kind);
            message += L" to the website at ";
            message += uri.get();
            message += L"?\n\n";
            message += L"Do you want to grant permission?\n";
            message += (userInitiated
                ? L"This request came from a user gesture."
                : L"This request did not come from a user gesture.");

            int response = MessageBox(
                nullptr, message.c_str(), L"Permission Request",
                MB_YESNOCANCEL | MB_ICONWARNING);
            switch (response) {
                case IDYES:
                    m_cached_permissions[cached_key] = true;
                    state = COREWEBVIEW2_PERMISSION_STATE_ALLOW;
                    break;
                case IDNO:
                    m_cached_permissions[cached_key] = false;
                    state = COREWEBVIEW2_PERMISSION_STATE_DENY;
                    break;
                default:
                    state = COREWEBVIEW2_PERMISSION_STATE_DEFAULT;
                    break;
            }
        }

        CHECK_FAILURE(args->put_State(state));
        CHECK_FAILURE(deferral->Complete());
    });
    return S_OK;
}

remove_PermissionRequested

Removes an event handler previously added with add_PermissionRequested.

public HRESULT remove_PermissionRequested(EventRegistrationToken token)