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| author | E.Z. Hart <hartez@users.noreply.github.com> | 2016-08-03 15:22:14 -0600 |
|---|---|---|
| committer | Jason Smith <jason.smith@xamarin.com> | 2016-08-03 14:22:14 -0700 |
| commit | b186254d1f4a0547c67f4fd30669df9d4cf36b65 (patch) | |
| tree | 6278a0f3217c726aed4e29c2027b10eb61522aeb /Xamarin.Forms.Platform.WinRT | |
| parent | b60fa6acf84d897d6283310e58b1c6c6365c391c (diff) | |
| download | xamarin-forms-b186254d1f4a0547c67f4fd30669df9d4cf36b65.tar.gz xamarin-forms-b186254d1f4a0547c67f4fd30669df9d4cf36b65.tar.bz2 xamarin-forms-b186254d1f4a0547c67f4fd30669df9d4cf36b65.zip | |
Enable WebView to render local HTML files on WinRT platforms (#277)
* Enable WebView to render local HTML files on WinRT platforms
* Add test to demonstrate that the solution works even if
<head> isn't in the HTML string
Diffstat (limited to 'Xamarin.Forms.Platform.WinRT')
| -rw-r--r-- | Xamarin.Forms.Platform.WinRT/WebViewRenderer.cs | 59 |
1 files changed, 52 insertions, 7 deletions
diff --git a/Xamarin.Forms.Platform.WinRT/WebViewRenderer.cs b/Xamarin.Forms.Platform.WinRT/WebViewRenderer.cs index 78d69abd..e3fcb898 100644 --- a/Xamarin.Forms.Platform.WinRT/WebViewRenderer.cs +++ b/Xamarin.Forms.Platform.WinRT/WebViewRenderer.cs @@ -1,8 +1,14 @@ using System; +using System.Collections.Generic; using System.ComponentModel; +using System.Diagnostics; +using System.Threading.Tasks; using Windows.UI.Core; +using Windows.UI.WebUI; using Windows.UI.Xaml.Controls; +using Windows.Web.Http; using Xamarin.Forms.Internals; +using static System.String; #if WINDOWS_UWP @@ -16,19 +22,59 @@ namespace Xamarin.Forms.Platform.WinRT { WebNavigationEvent _eventState; bool _updating; + const string LocalScheme = "ms-appx-web:///"; + + // Script to insert a <base> tag into an HTML document + const string BaseInsertionScript = @" +var head = document.getElementsByTagName('head')[0]; +var bases = head.getElementsByTagName('base'); +if(bases.length == 0){ + head.innerHTML = 'baseTag' + head.innerHTML; +}"; public void LoadHtml(string html, string baseUrl) { - /* - * FIXME: If baseUrl is a file URL, set the Base property to its path. - * Otherwise, it doesn't seem as if WebBrowser can handle it. - */ - Control.NavigateToString(html); + if (IsNullOrEmpty(baseUrl)) + { + baseUrl = LocalScheme; + } + + // Generate a base tag for the document + var baseTag = $"<base href=\"{baseUrl}\"></base>"; + + string htmlWithBaseTag; + + // Set up an internal WebView we can use to load and parse the original HTML string + var internalWebView = new Windows.UI.Xaml.Controls.WebView(); + + // When the 'navigation' to the original HTML string is done, we can modify it to include our <base> tag + internalWebView.NavigationCompleted += async (sender, args) => + { + // Generate a version of the <base> script with the correct <base> tag + var script = BaseInsertionScript.Replace("baseTag", baseTag); + + // Run it and retrieve the updated HTML from our WebView + await sender.InvokeScriptAsync("eval", new[] { script }); + htmlWithBaseTag = await sender.InvokeScriptAsync("eval", new[] { "document.documentElement.outerHTML;" }); + + // Set the HTML for the 'real' WebView to the updated HTML + Control.NavigateToString(!IsNullOrEmpty(htmlWithBaseTag) ? htmlWithBaseTag : html); + }; + + // Kick off the initial navigation + internalWebView.NavigateToString(html); } public void LoadUrl(string url) { - Control.Source = new Uri(url); + Uri uri = new Uri(url, UriKind.RelativeOrAbsolute); + + if (!uri.IsAbsoluteUri) + { + uri = new Uri(LocalScheme + url, UriKind.RelativeOrAbsolute); + } + + Control.Source = uri; } protected override void Dispose(bool disposing) @@ -165,7 +211,6 @@ namespace Xamarin.Forms.Platform.WinRT _eventState = WebNavigationEvent.NewPage; } - // Nasty hack because we cant bind this because OneWayToSource isn't a thing in WP8, yay void UpdateCanGoBackForward() { Element.CanGoBack = Control.CanGoBack; |